: the representation of rape in Lewis Nkosi’s Mating Birds and Arthur Maimane’s Hate No More
- Authors: Yawa, Sibulele Yola
- Date: 2021-02
- Subjects: South Africa--Politics and government--1994 , Post-apartheid era--South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21134 , vital:47131
- Description: The main aim of this thesis is to provide a literary study through a comparative analysis of how sexual politics are played out in the texts Mating Birds by Lewis Nkosi and Hate No More by Arthur Maimane. It seeks to determine the modalities of representation of rape in each text and also to investigate the extent to which the novels are similar or different in the way in which they represent sexual politics or the politics of rape during the apartheid era. This investigation was done using Frantz Fanon‟s postcolonial theory and, particularly, his seminal work, Black Skin, White Masks. Most importantly, for the purpose of this study, is Fanon‟s chapter on the love/sexual relationships between the man of colour and the white woman. This is helpful as Fanon touches on what he believes the attraction of the man of colour to the white woman stems from. Using Fanon‟s theory, one discovers that the motivation for Ndi Sibiya to allegedly rape Veronica stems from his anger at the system of apartheid and its oppression of black people. This is similar to Philip Mokone‟s case; the novel explicitly states that he was motivated by anger and his rape of Jean Ryan was a form of communication to the white people and the apartheid system. , Thesis (MA) (English) -- University of Fort Hare, 2021
- Full Text:
- Authors: Yawa, Sibulele Yola
- Date: 2021-02
- Subjects: South Africa--Politics and government--1994 , Post-apartheid era--South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21134 , vital:47131
- Description: The main aim of this thesis is to provide a literary study through a comparative analysis of how sexual politics are played out in the texts Mating Birds by Lewis Nkosi and Hate No More by Arthur Maimane. It seeks to determine the modalities of representation of rape in each text and also to investigate the extent to which the novels are similar or different in the way in which they represent sexual politics or the politics of rape during the apartheid era. This investigation was done using Frantz Fanon‟s postcolonial theory and, particularly, his seminal work, Black Skin, White Masks. Most importantly, for the purpose of this study, is Fanon‟s chapter on the love/sexual relationships between the man of colour and the white woman. This is helpful as Fanon touches on what he believes the attraction of the man of colour to the white woman stems from. Using Fanon‟s theory, one discovers that the motivation for Ndi Sibiya to allegedly rape Veronica stems from his anger at the system of apartheid and its oppression of black people. This is similar to Philip Mokone‟s case; the novel explicitly states that he was motivated by anger and his rape of Jean Ryan was a form of communication to the white people and the apartheid system. , Thesis (MA) (English) -- University of Fort Hare, 2021
- Full Text:
A framework to improve social media as a communication tool in technical vocational education and training colleges in South Africa: a case of twitter.
- Nyamanhare, Sangudzayi Innocent
- Authors: Nyamanhare, Sangudzayi Innocent
- Date: 2021-02
- Subjects: Social media , Education, Higher , Universities and colleges
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20495 , vital:46008
- Description: South Africa uses social media as a communication tool. The use of Twitter as a communication tool in Technical Vocational Education and Training Colleges (TVET) in South Africa is a crucial factor for efficient and effective communication between TVET College administration and stakeholders such as prospective students, students, prospective employers, prospective employees and the Twitter community which follow various Twitter accounts. Literature has found that TVET Colleges use Twitter in a monologic manner which promotes one-way information flow. Twitter is also used in a limited fashion and within silos within TVET Colleges that have incorporated this social media platform into their communication strategy. The main purpose of this research study was to develop a framework to improve social media as a communication tool in TVET Colleges in South Africa. The Social Media-Integration- Theory-Model was used as the theoretical framework to evaluate the use of Twitter in TVET Colleges in South Africa, thus enabling the development of critical success factors to improve the use of social media as a communication tool. The Interpretivist paradigm and qualitative research approach was chosen for this study. Netnography was used to collect the online data from Twitter that was analysed in the study. Data was collected from 36 TVET Colleges in South Africa that have a Twitter account over a one-year period (April 2019 – March 2020). After the data collection, content and thematic analysis were used to analyse the date. The study developed a framework from the analyses of tweets which incorporated the four constructs from the Social-Media-Integration-Theory-Model. The study also developed five critical success factors, namely, procuring and maintaining of ICT infrastructure; implementing a policy that guide the use of social networks for communication purposes in TVET Colleges; raising awareness on the use of Twitter as a tool for communication; intensive training to manage administration of Twitter accounts and appointing champions to promote Twitter as a communication tool in TVET Colleges. , Thesis (MCom) (Information Systems)-- University of Fort Hare, 2021
- Full Text:
- Authors: Nyamanhare, Sangudzayi Innocent
- Date: 2021-02
- Subjects: Social media , Education, Higher , Universities and colleges
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20495 , vital:46008
- Description: South Africa uses social media as a communication tool. The use of Twitter as a communication tool in Technical Vocational Education and Training Colleges (TVET) in South Africa is a crucial factor for efficient and effective communication between TVET College administration and stakeholders such as prospective students, students, prospective employers, prospective employees and the Twitter community which follow various Twitter accounts. Literature has found that TVET Colleges use Twitter in a monologic manner which promotes one-way information flow. Twitter is also used in a limited fashion and within silos within TVET Colleges that have incorporated this social media platform into their communication strategy. The main purpose of this research study was to develop a framework to improve social media as a communication tool in TVET Colleges in South Africa. The Social Media-Integration- Theory-Model was used as the theoretical framework to evaluate the use of Twitter in TVET Colleges in South Africa, thus enabling the development of critical success factors to improve the use of social media as a communication tool. The Interpretivist paradigm and qualitative research approach was chosen for this study. Netnography was used to collect the online data from Twitter that was analysed in the study. Data was collected from 36 TVET Colleges in South Africa that have a Twitter account over a one-year period (April 2019 – March 2020). After the data collection, content and thematic analysis were used to analyse the date. The study developed a framework from the analyses of tweets which incorporated the four constructs from the Social-Media-Integration-Theory-Model. The study also developed five critical success factors, namely, procuring and maintaining of ICT infrastructure; implementing a policy that guide the use of social networks for communication purposes in TVET Colleges; raising awareness on the use of Twitter as a tool for communication; intensive training to manage administration of Twitter accounts and appointing champions to promote Twitter as a communication tool in TVET Colleges. , Thesis (MCom) (Information Systems)-- University of Fort Hare, 2021
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Adolescent sexual reproductive health and rights in the Alice area, Eastern Cape Province of South Africa
- Authors: Moko, Zukhanye
- Date: 2021-02
- Subjects: Reproductive health , Right to health , HIV infections
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20676 , vital:46423
- Description: Sexual Reproductive Health (SRH) is a significant aspect of adolescent’s growth. Adolescents particularly girls face the risk of exposure to Human Immunodeficiency Virus (HIV), Sexually Transmitted Diseases (STDs), child marriages, high rates of unwanted pregnancy and the risk of those pregnancies can lead to unsafe abortion. In South Africa, considerable progress has been made in achieving improved access to Sexual Reproductive Health and Rights (SRHR) among the general population, however, some factors influencing SRHR of adolescents and young people have been slow to achieve. The study aims to investigate factors influencing Sexual Reproductive Health and Rights of adolescents in Alice, which is located in the Eastern Cape Province of South Africa. The Social-Ecological Model was considered appropriate for this study as it provides a comprehensive understanding of the multiple and interacting determinants of Sexual Reproductive Health and Rights. A qualitative methodology was adopted, involving focus groups with high school learners, in-depth interviews with institutional actors (Department of Health, Basic Education and Social Development), and participant observations. The study reveals that adolescents’ have access to Sexual Reproductive Health services from healthcare centres but only a few utilize or access them due to barriers such as the geographical location, denial and judgement about young people's sexuality limits their access to comprehensive knowledge to protect and promote their Sexual and Reproductive Health. The findings show that the adolescents who were most affected by Sexual Reproductive Health and Rights challenges were those from deep rural areas. They had minimal information/education compared to those residing in areas close to the town of Alice and major roads. Multi-sectoral interventions empowering adolescents and young people to exercise their rights to optimize SRHR service yield better results. , Thesis (MSc) -- Faculty of Science & Agriculture, 2021
- Full Text:
- Authors: Moko, Zukhanye
- Date: 2021-02
- Subjects: Reproductive health , Right to health , HIV infections
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20676 , vital:46423
- Description: Sexual Reproductive Health (SRH) is a significant aspect of adolescent’s growth. Adolescents particularly girls face the risk of exposure to Human Immunodeficiency Virus (HIV), Sexually Transmitted Diseases (STDs), child marriages, high rates of unwanted pregnancy and the risk of those pregnancies can lead to unsafe abortion. In South Africa, considerable progress has been made in achieving improved access to Sexual Reproductive Health and Rights (SRHR) among the general population, however, some factors influencing SRHR of adolescents and young people have been slow to achieve. The study aims to investigate factors influencing Sexual Reproductive Health and Rights of adolescents in Alice, which is located in the Eastern Cape Province of South Africa. The Social-Ecological Model was considered appropriate for this study as it provides a comprehensive understanding of the multiple and interacting determinants of Sexual Reproductive Health and Rights. A qualitative methodology was adopted, involving focus groups with high school learners, in-depth interviews with institutional actors (Department of Health, Basic Education and Social Development), and participant observations. The study reveals that adolescents’ have access to Sexual Reproductive Health services from healthcare centres but only a few utilize or access them due to barriers such as the geographical location, denial and judgement about young people's sexuality limits their access to comprehensive knowledge to protect and promote their Sexual and Reproductive Health. The findings show that the adolescents who were most affected by Sexual Reproductive Health and Rights challenges were those from deep rural areas. They had minimal information/education compared to those residing in areas close to the town of Alice and major roads. Multi-sectoral interventions empowering adolescents and young people to exercise their rights to optimize SRHR service yield better results. , Thesis (MSc) -- Faculty of Science & Agriculture, 2021
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An analysis of students’ constructions of the ‘fees must Fall’ movement at an historically black university
- Authors: Chandler, Kelly Jean
- Date: 2021-02
- Subjects: Student movements , College students--Political activity , Student protesters
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21058 , vital:46939
- Description: The ‘Fees Must Fall’ movement which occured in 2015 and 2016 was a major national event which affected most higher education institutions in South Africa. This research considers the constructions of the ‘Fees Must Fall’ movement at an historically black university, namely, the University of Fort Hare. Furthermore, the research analyzes how students are positioned in their constructions in relation to the movement. The study aims to contribute to the understanding of the lived experiences of student activists in the 2015 and 2016 ‘Fees Must Fall’ movement at the University of Fort Hare. The data collection method used was a convenience sampling method with seven participants interviewed. Making use of the guidelines of a Foucauldian Discourse Analysis, four primary discourses were identified from the data collected: coercion discourses; fear discourses; financial discourses; and meritocracy discourses. The positions of students were varied and consisted of both agentic and submissive positions, with the student representative council frequently being positioned dominantly. The theoretical framework also included Michel Foucault’s theories of governmentality and biopower which contributed significantly to the understandings of institutional power in the university context. The research is conducted against ethical backdrop of the philosophies and guidelines of postcolonial psychology. The broader context of South Africa is observed and discussed, specifically recognizing the legacy of apartheid and other historical antecedents such as colonization. The issues of transformation, institutional racism, and decolonization are placed at the forefront of this research endeavour. , Thesis (MSoc Sci) (Psychology) - - University of Fort Hare, 2021
- Full Text:
- Authors: Chandler, Kelly Jean
- Date: 2021-02
- Subjects: Student movements , College students--Political activity , Student protesters
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21058 , vital:46939
- Description: The ‘Fees Must Fall’ movement which occured in 2015 and 2016 was a major national event which affected most higher education institutions in South Africa. This research considers the constructions of the ‘Fees Must Fall’ movement at an historically black university, namely, the University of Fort Hare. Furthermore, the research analyzes how students are positioned in their constructions in relation to the movement. The study aims to contribute to the understanding of the lived experiences of student activists in the 2015 and 2016 ‘Fees Must Fall’ movement at the University of Fort Hare. The data collection method used was a convenience sampling method with seven participants interviewed. Making use of the guidelines of a Foucauldian Discourse Analysis, four primary discourses were identified from the data collected: coercion discourses; fear discourses; financial discourses; and meritocracy discourses. The positions of students were varied and consisted of both agentic and submissive positions, with the student representative council frequently being positioned dominantly. The theoretical framework also included Michel Foucault’s theories of governmentality and biopower which contributed significantly to the understandings of institutional power in the university context. The research is conducted against ethical backdrop of the philosophies and guidelines of postcolonial psychology. The broader context of South Africa is observed and discussed, specifically recognizing the legacy of apartheid and other historical antecedents such as colonization. The issues of transformation, institutional racism, and decolonization are placed at the forefront of this research endeavour. , Thesis (MSoc Sci) (Psychology) - - University of Fort Hare, 2021
- Full Text:
Bio-utilization of keratinous waste biomass for the production of keratinolytic proteases by Chryseobactreium aquifrigidense isolated from poultry waste dumpsite
- Authors: Bokveld, Amahle
- Date: 2021-02
- Subjects: Keratin
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20550 , vital:46120
- Description: Keratin is an insoluble and a fibrous protein that is mostly found in feathers, animal wool, and hair, making them mechanically stable. Avian feathers are the most ubiquitously generated keratinous waste biomass from the poultry processing plants. Keratinous waste biomass valorization could produce amino acids and bioactive peptides. Hence, the bio-recycling of keratin-rich wastes bears an advantage over the chemical and thermal means. In recent times, the microbial keratinases continues to gain traction due to the litany of their potential significance in green technology. Consequently, this study assessed chicken feather degrading and keratinase production potentials of bacteria isolated from a local poultry dumpsite. Soil samples were collected from the poultry dumpsite. Bacteria were isolated using basal salt medium and screened for keratinolytic activity. The identification of potent chicken feather degrading bacterial isolates was through 16S rRNA gene sequence analysis. Keratinase production efficiency of isolates on chicken feather constituted medium was optimized. Hydrolysate's amino acid compositions were quantified, and the keratinases produced was characterized. Out of 22 bacteria isolated from the soil samples, 12 showed a varying degree of proteolytic activity on skimmed milk agar. Four (4) isolates, coded as FPS-01, FPS-07, FPS-09, WDS-06, out of the 12 proteolytic strains further displayed remarkable degradation of the intact chicken feather; percentage degradation ranged from 69 percent for FPS-01 to 88 percent for FPS-09. The extracellular keratinase activity ranged from 610.91 ± 56.57 U/mL for WDS-06 and 834.55 ± 66.86 U/mL for FPS-07. Additionally, the sulfhydryl group concentration quantified from the fermentation broth was 2.22 ± 0.37 (mM), 0.22 ± 0.08 (mM), 2.27 ± 0.09 (mM), and 2.76 ± 0.79 (mM) for FPS-01, FPS-07, FPS-09 and WDS-06, respectively. Based on 16S rRNA gene sequencing and phylogenetic analyses, the isolates FPS-07 and FPS-09 were identified as Chryseobacterium aquifrigidense FANN1 and Chryseobacterium aquifrigidense FANN2. Following the optimization process, the improved fermentation conditions were pH 6, inoculum side (4 percent, v/v), temperature (30 oC), and chicken feather (0.5-1.5 percent, w/v) for FANN1. FANN2 optimal fermentation conditions were pH 6, inoculum (5 percent, v/v), temperature (30 oC), and chicken feather (1.5 percent, w/v). Both bacterial isolates showed the highest extracellular keratinase production after 72 h of the fermentation time. Analysis of the hydrolysates generated from the bacteria fermentation showed a high concentration of arginine, serine, glutamic acid, glycine, proline, valine, and leucine at a respective concentration of 1.13, 1.02, 0.83, 0.94, 0.85, 0.84, and 0.86 (g/100g sample) against FANN1. Similarly, FANN2 generated hydrolysate showed high concentrations of glutamic acid, arginine, serine, aspartic acid, and glycine at this respective abundance 2.52, 1.92, 2.12, 2.25 and 1.9 (g/100g sample). Keratinases from FANN1 and FANN2 showed optimal catalytic efficiency at pH 8 and temperature between 40-50 oC. The enzyme was considerably thermostable at 40 oC and 50 oC after 120 min of preheating. Both FANN1 and FANN2 showed variable residual activity in the presence of the different metal ions. Keratinase from FANN1 recorded the following residual activity of Fe3+ (120 ± 5.06 percent), Ca2+ (100 ± 10.33 percent), Na+ (122 ± 2.95 percent), Al3+ (106 ± 10.33 percent). Likewise, FANN2 keratinase showed remarkable stability against Na+ (108 ± 13.71 percent), Ba2+ (102 ± 0.86 percent), Al3+ (105 ± 2.57 percent), and Ca2+ (96 ± 2.99 percent). Keratinase from FANN1 was catalytically activated after 60 min of pre-treatment with the following detergents, Sunlight (129 percent), Ariel (116 percent), MAQ (151 percent), and Surf (143 percent) compared to the control. FANN2 keratinase showed less stability with laundry detergents after 60 min of preincubation. FANN1 keratinase showed remarkable stability in the presence of chemical agents tested, with residual activity of 90 ± 0.18 percent, 105 ± 7.55 percent, 108 ± 4.31 percent, 123 ± 1.44 percent, 132 ± 1.26 percent, 96 ± 7.19 percent, and 101 ± 3.06 percent for DTT, hydrogen peroxide, DMSO, acetonitrile, triton X-100, tween-80, and SDS, respectively. The enzyme activity was also considerably inhibited by PMSF and EDTA, which suggested a mixed type of protease. Furthermore, keratinase from FANN2 was inhibited by EDTA, and such inhibition pattern grouped it as a metallo-type of protease. The enzyme was also stable in the presence of other chemical agents tested. Therefore, the findings suggest the isolates and their enzymes' relevance to sustainable recycling of recalcitrant keratinous wastes into high-value products with immense application potentials. The remarkable stability shown by keratinases from FANN1 and FANN2, post detergent and chemical agents pre-treatment, indicates promise for the biotechnology and industrial sector. , Thesis(MSc) (Microbiology) -- University of Fort Hare, 2021
- Full Text:
- Authors: Bokveld, Amahle
- Date: 2021-02
- Subjects: Keratin
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20550 , vital:46120
- Description: Keratin is an insoluble and a fibrous protein that is mostly found in feathers, animal wool, and hair, making them mechanically stable. Avian feathers are the most ubiquitously generated keratinous waste biomass from the poultry processing plants. Keratinous waste biomass valorization could produce amino acids and bioactive peptides. Hence, the bio-recycling of keratin-rich wastes bears an advantage over the chemical and thermal means. In recent times, the microbial keratinases continues to gain traction due to the litany of their potential significance in green technology. Consequently, this study assessed chicken feather degrading and keratinase production potentials of bacteria isolated from a local poultry dumpsite. Soil samples were collected from the poultry dumpsite. Bacteria were isolated using basal salt medium and screened for keratinolytic activity. The identification of potent chicken feather degrading bacterial isolates was through 16S rRNA gene sequence analysis. Keratinase production efficiency of isolates on chicken feather constituted medium was optimized. Hydrolysate's amino acid compositions were quantified, and the keratinases produced was characterized. Out of 22 bacteria isolated from the soil samples, 12 showed a varying degree of proteolytic activity on skimmed milk agar. Four (4) isolates, coded as FPS-01, FPS-07, FPS-09, WDS-06, out of the 12 proteolytic strains further displayed remarkable degradation of the intact chicken feather; percentage degradation ranged from 69 percent for FPS-01 to 88 percent for FPS-09. The extracellular keratinase activity ranged from 610.91 ± 56.57 U/mL for WDS-06 and 834.55 ± 66.86 U/mL for FPS-07. Additionally, the sulfhydryl group concentration quantified from the fermentation broth was 2.22 ± 0.37 (mM), 0.22 ± 0.08 (mM), 2.27 ± 0.09 (mM), and 2.76 ± 0.79 (mM) for FPS-01, FPS-07, FPS-09 and WDS-06, respectively. Based on 16S rRNA gene sequencing and phylogenetic analyses, the isolates FPS-07 and FPS-09 were identified as Chryseobacterium aquifrigidense FANN1 and Chryseobacterium aquifrigidense FANN2. Following the optimization process, the improved fermentation conditions were pH 6, inoculum side (4 percent, v/v), temperature (30 oC), and chicken feather (0.5-1.5 percent, w/v) for FANN1. FANN2 optimal fermentation conditions were pH 6, inoculum (5 percent, v/v), temperature (30 oC), and chicken feather (1.5 percent, w/v). Both bacterial isolates showed the highest extracellular keratinase production after 72 h of the fermentation time. Analysis of the hydrolysates generated from the bacteria fermentation showed a high concentration of arginine, serine, glutamic acid, glycine, proline, valine, and leucine at a respective concentration of 1.13, 1.02, 0.83, 0.94, 0.85, 0.84, and 0.86 (g/100g sample) against FANN1. Similarly, FANN2 generated hydrolysate showed high concentrations of glutamic acid, arginine, serine, aspartic acid, and glycine at this respective abundance 2.52, 1.92, 2.12, 2.25 and 1.9 (g/100g sample). Keratinases from FANN1 and FANN2 showed optimal catalytic efficiency at pH 8 and temperature between 40-50 oC. The enzyme was considerably thermostable at 40 oC and 50 oC after 120 min of preheating. Both FANN1 and FANN2 showed variable residual activity in the presence of the different metal ions. Keratinase from FANN1 recorded the following residual activity of Fe3+ (120 ± 5.06 percent), Ca2+ (100 ± 10.33 percent), Na+ (122 ± 2.95 percent), Al3+ (106 ± 10.33 percent). Likewise, FANN2 keratinase showed remarkable stability against Na+ (108 ± 13.71 percent), Ba2+ (102 ± 0.86 percent), Al3+ (105 ± 2.57 percent), and Ca2+ (96 ± 2.99 percent). Keratinase from FANN1 was catalytically activated after 60 min of pre-treatment with the following detergents, Sunlight (129 percent), Ariel (116 percent), MAQ (151 percent), and Surf (143 percent) compared to the control. FANN2 keratinase showed less stability with laundry detergents after 60 min of preincubation. FANN1 keratinase showed remarkable stability in the presence of chemical agents tested, with residual activity of 90 ± 0.18 percent, 105 ± 7.55 percent, 108 ± 4.31 percent, 123 ± 1.44 percent, 132 ± 1.26 percent, 96 ± 7.19 percent, and 101 ± 3.06 percent for DTT, hydrogen peroxide, DMSO, acetonitrile, triton X-100, tween-80, and SDS, respectively. The enzyme activity was also considerably inhibited by PMSF and EDTA, which suggested a mixed type of protease. Furthermore, keratinase from FANN2 was inhibited by EDTA, and such inhibition pattern grouped it as a metallo-type of protease. The enzyme was also stable in the presence of other chemical agents tested. Therefore, the findings suggest the isolates and their enzymes' relevance to sustainable recycling of recalcitrant keratinous wastes into high-value products with immense application potentials. The remarkable stability shown by keratinases from FANN1 and FANN2, post detergent and chemical agents pre-treatment, indicates promise for the biotechnology and industrial sector. , Thesis(MSc) (Microbiology) -- University of Fort Hare, 2021
- Full Text:
Bioconversion of chicken feather into amino acids and keratinase production by mesophilic Chryseobacterium proteolyticum and Pseudomonas aeruginosa isolated from municipal waste dumpsites
- Giwu, Nonkonzo https://orcid.org/0000-0001-9416-7896
- Authors: Giwu, Nonkonzo https://orcid.org/0000-0001-9416-7896
- Date: 2021-02
- Subjects: Poultry -- Processing , Proteolytic enzymes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22732 , vital:52720
- Description: Chicken feathers are by-products of poultry processing which are generated in large amount because of the global growing demand for poultry meats. They have high contents of crude proteins in the form of keratin which could be valorized into digestible products. Keratinases are classified as a specific collection of proteolytic enzymes that have the ability for the degradation of recalcitrant keratinous substrates. Isolation and characterization of these enzymes from various microbial producers are gaining prominence in recent years due to their industrial and biotechnological application potentials. For this research, the collection of soil samples was done as well as the isolation of bacteria and the screening for keratinolytic activity. 16S rDNA sequencing and phylogenetic analysis were used to identify the isolates with efficient chicken feathers degrading capacity. Optimum conditions for the fermentation prcocess was enhanced for the production of keratinase. The fermentation broth was also analysed for various amino acids of protein, and the biochemical properties of the enzymes were likewise determined. Twenty two (22) bacteria were isolated from the soil samples, and 18 out of the 22 isolates showed proteolytic activity on solid media with diameters of halo zone that ranged from 5 ± 0.71 mm for isolate coded as PSS-03 to 25 ± 1.41 mm for isolate coded as PSS-06. Intact chicken feathers were degraded by proteolytic bacterial isolates in variable degree that ranged from 24percent for PSS-10 and 81percent for DSS-02. Extracellular keratinase production recorded for the isolates ranged from 63.63 ± 4.14 U/mL for PSS-10 to 693.63 ± 62.99 U/mL for DSS-02. Based on 16S rDNA sequence and phylogenetic analysis, the 2 isolates with remarkable keratinolytic activity coded as DSS-02 and PSS-14 were identified as Chryseobacterium proteolyticum FGNn and Pseudomonas aeruginosa GNFx. C. proteolyticum showed the maximum keratinase production of 756.36 U/mL after 72 h of incubation at optimized fermentation conditions which involved initial medium pH (4), incubation temperature (30 oC), inoculum size (2percent; v/v), and chicken feathers (1.5percent; w/v). Similarly, P. aeruginosa optimally produced keratinase (1055.45 U/mL) after 96 h of incubation at optimized fermentation conditions that involved initial medium pH (7-8), incubation temperature (30 oC), inoculum size (5percent; v/v), and chicken feathers (2.5percent; w/v). Furthermore, feather hydrolysate from C. proteolyticum FGNn had relatively higher abundance (>1.5g/100g sample) of arginine (1.85), serine (1.63), glycine (1.9) and lysine (1.62); while P. aeruginosa GNFx feather hydrolysate showed high abundance of arginine, serine, aspartic acid, glutamic acid, glycine, alanine, valine, and leucine with respective concentration of 2.06, 1.67, 2.39, 3.05, 1.87, 1.73, 1.56 and 1.65 (g/100g sample). The results showed that keratinases from the two bacterial isolates were optimally active at pH 8, and temperature of 50 oC for FGNn keratinase and 50-60 oC for GNFx keratinase. The enzymes displayed remarkable pH stability. Keratinase from C. proteolyticum was catalytically inhibited by EDTA and 1,10-phenanthroline but not affected by PMSF; while P. aeruginosa keratinase was not significantly affected by those class of protease inhibitors. Adiitionally, FGNn keratinase demonstrated high residual activity of 90percent, 103percent, 101percent, 110percent, 130, and 105percent in the presence of DTT, hydrogen peroxides, acetonitrile, triton X-100, tween-80 and SDS, respectively. Similarly, catalytic efficiency of GNFx keratinase was promoted in the presence of hydrogen peroxides (119percent), triton X-100 (140percent), tween-80 (150percent) and SDS (147percent) compared to the control. Furthermore, the keratinases from the both bacterial isolates exhibited catalytic efficiency enhancement and remarkable structural stability in the presence of laundry detergents tested. The findings from the study suggest the application potentials of the isolates for the bioconversion of recalcitrant keratinous wastes into digestible and quality protein hydrolysates. The properties of these microbial keratinases indicate that they may be exploited for various biotechnological and industrial processes especially in the formulation of detergents. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Authors: Giwu, Nonkonzo https://orcid.org/0000-0001-9416-7896
- Date: 2021-02
- Subjects: Poultry -- Processing , Proteolytic enzymes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22732 , vital:52720
- Description: Chicken feathers are by-products of poultry processing which are generated in large amount because of the global growing demand for poultry meats. They have high contents of crude proteins in the form of keratin which could be valorized into digestible products. Keratinases are classified as a specific collection of proteolytic enzymes that have the ability for the degradation of recalcitrant keratinous substrates. Isolation and characterization of these enzymes from various microbial producers are gaining prominence in recent years due to their industrial and biotechnological application potentials. For this research, the collection of soil samples was done as well as the isolation of bacteria and the screening for keratinolytic activity. 16S rDNA sequencing and phylogenetic analysis were used to identify the isolates with efficient chicken feathers degrading capacity. Optimum conditions for the fermentation prcocess was enhanced for the production of keratinase. The fermentation broth was also analysed for various amino acids of protein, and the biochemical properties of the enzymes were likewise determined. Twenty two (22) bacteria were isolated from the soil samples, and 18 out of the 22 isolates showed proteolytic activity on solid media with diameters of halo zone that ranged from 5 ± 0.71 mm for isolate coded as PSS-03 to 25 ± 1.41 mm for isolate coded as PSS-06. Intact chicken feathers were degraded by proteolytic bacterial isolates in variable degree that ranged from 24percent for PSS-10 and 81percent for DSS-02. Extracellular keratinase production recorded for the isolates ranged from 63.63 ± 4.14 U/mL for PSS-10 to 693.63 ± 62.99 U/mL for DSS-02. Based on 16S rDNA sequence and phylogenetic analysis, the 2 isolates with remarkable keratinolytic activity coded as DSS-02 and PSS-14 were identified as Chryseobacterium proteolyticum FGNn and Pseudomonas aeruginosa GNFx. C. proteolyticum showed the maximum keratinase production of 756.36 U/mL after 72 h of incubation at optimized fermentation conditions which involved initial medium pH (4), incubation temperature (30 oC), inoculum size (2percent; v/v), and chicken feathers (1.5percent; w/v). Similarly, P. aeruginosa optimally produced keratinase (1055.45 U/mL) after 96 h of incubation at optimized fermentation conditions that involved initial medium pH (7-8), incubation temperature (30 oC), inoculum size (5percent; v/v), and chicken feathers (2.5percent; w/v). Furthermore, feather hydrolysate from C. proteolyticum FGNn had relatively higher abundance (>1.5g/100g sample) of arginine (1.85), serine (1.63), glycine (1.9) and lysine (1.62); while P. aeruginosa GNFx feather hydrolysate showed high abundance of arginine, serine, aspartic acid, glutamic acid, glycine, alanine, valine, and leucine with respective concentration of 2.06, 1.67, 2.39, 3.05, 1.87, 1.73, 1.56 and 1.65 (g/100g sample). The results showed that keratinases from the two bacterial isolates were optimally active at pH 8, and temperature of 50 oC for FGNn keratinase and 50-60 oC for GNFx keratinase. The enzymes displayed remarkable pH stability. Keratinase from C. proteolyticum was catalytically inhibited by EDTA and 1,10-phenanthroline but not affected by PMSF; while P. aeruginosa keratinase was not significantly affected by those class of protease inhibitors. Adiitionally, FGNn keratinase demonstrated high residual activity of 90percent, 103percent, 101percent, 110percent, 130, and 105percent in the presence of DTT, hydrogen peroxides, acetonitrile, triton X-100, tween-80 and SDS, respectively. Similarly, catalytic efficiency of GNFx keratinase was promoted in the presence of hydrogen peroxides (119percent), triton X-100 (140percent), tween-80 (150percent) and SDS (147percent) compared to the control. Furthermore, the keratinases from the both bacterial isolates exhibited catalytic efficiency enhancement and remarkable structural stability in the presence of laundry detergents tested. The findings from the study suggest the application potentials of the isolates for the bioconversion of recalcitrant keratinous wastes into digestible and quality protein hydrolysates. The properties of these microbial keratinases indicate that they may be exploited for various biotechnological and industrial processes especially in the formulation of detergents. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
Chicken feather delipidation by lipolytic bacteria isolated from an aquatic environment
- Shiri, Tariro https://orcid.org/0000-0002-0290-9854
- Authors: Shiri, Tariro https://orcid.org/0000-0002-0290-9854
- Date: 2021-02
- Subjects: Keratin
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21479 , vital:48693
- Description: Keratinous biomass contributes a significant proportion of agro-based wastes in the ecosystem with minimal potentials for valuable product recovery. The generation of huge quantities of chicken feather from poultry processing farms prompts the valorization attempt via diverse avenues. Chicken feathers are a rich source of valuable keratin, yet the overall value chain is rudimentary based on unsustainable recovery techniques involving corrosive chemicals and high energy input processes. Although attempts have been made to extract keratin using microbial techniques successfully, the pre-treatment stage remains dominated by chemical use. Chicken feathers are composed of approximately 91percent keratin, 1percent lipids, and 8percent water. Therefore, lipid removal is a critical step in the valorization process as they contribute to access hindrance of the keratinases and other sulfitolytic systems to keratin. Consequently, the study undertook to explore the environment for lipolytic bacteria capable of degrading chicken feathers' lipid components. Sediment samples were collected for bacteria isolation. The bacteria were evaluated for lipolytic activity, and the potent isolates were identified based on 16S rRNA gene sequencing. The fermentation conditions for the production of extracellular lipases were optimized, and the produced lipases were characterized. Lastly, chicken feather lipids were hydrolysed with lipolytic bacteria. Out of twenty bacteria isolated from the sediment samples, six isolates coded as ACT003, ACT004, ACT010, ACT013, ACT016, and ACT019 showed lipolytic activity on solid media with a respective diameter of 12 mm, 66 mm, 29 mm, 11 mm, 12 mm, and 10 mm. Based on 16S rRNA gene sequencing and phylogenetic analysis, the isolates coded as ACT004 and ACT010 were identified as Bacillus sp. TTs1 and Bacillus sp. TTs2; and the nucleotide sequences were submitted to GenBank (NCBI) with the accession numbers MW556206 and MW556207, respectively. Bacillus sp. TTs1 showed the maximum lipase production of 641.25 U/mL at 72 h, under optimized conditions that included initial pH (5), inoculum size (2percent, v/v), incubation temperature (45 oC), agitation speed (140 rpm), CaCl2 (0.01percent, w/v), yeast extract (1percent, w/v), and tween-80 (10percent, v/v). Similarly, the lipase production by Bacillus sp. TTs2 peaked at 96 h with enzyme activity of 618.8 U/mL in improved fermentation conditions consisting of initial pH (5), inoculum size (2-8percent, v/v), incubation temperature (25 oC), agitation speed (180 rpm), CaCl2 (0.01percent, w/v), yeast extract and peptone (1percent, w/v), and tween-80 (10percent, v/v). The evaluation of chicken feather concentrations on free fatty acid liberation showed that 6-8percent (w/v) chicken feather was adequate with free fatty acids contents of 0.58percent and 0.86percent for Bacillus sp. TTs1 and Bacillus sp. TTs2, respectively. Both isolates' lipases showed remarkable catalytic efficiency at pH and temperature of 7 and 40oC, respectively. The comparative analysis of residual lipids between pre-and post-fermentation indicated a 39.9 ± 7.8percent and 51.2 ± 20.2percent hydrolysis efficiency for Bacillus sp. TTs1 and Bacillus sp. TTs2, respectively. This study's findings indicated the lipolytic potentials of Bacillus spp. and suggest the possibility of a full bio-based approach for chicken feather lipid removal in the valorization of chicken feathers. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Authors: Shiri, Tariro https://orcid.org/0000-0002-0290-9854
- Date: 2021-02
- Subjects: Keratin
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21479 , vital:48693
- Description: Keratinous biomass contributes a significant proportion of agro-based wastes in the ecosystem with minimal potentials for valuable product recovery. The generation of huge quantities of chicken feather from poultry processing farms prompts the valorization attempt via diverse avenues. Chicken feathers are a rich source of valuable keratin, yet the overall value chain is rudimentary based on unsustainable recovery techniques involving corrosive chemicals and high energy input processes. Although attempts have been made to extract keratin using microbial techniques successfully, the pre-treatment stage remains dominated by chemical use. Chicken feathers are composed of approximately 91percent keratin, 1percent lipids, and 8percent water. Therefore, lipid removal is a critical step in the valorization process as they contribute to access hindrance of the keratinases and other sulfitolytic systems to keratin. Consequently, the study undertook to explore the environment for lipolytic bacteria capable of degrading chicken feathers' lipid components. Sediment samples were collected for bacteria isolation. The bacteria were evaluated for lipolytic activity, and the potent isolates were identified based on 16S rRNA gene sequencing. The fermentation conditions for the production of extracellular lipases were optimized, and the produced lipases were characterized. Lastly, chicken feather lipids were hydrolysed with lipolytic bacteria. Out of twenty bacteria isolated from the sediment samples, six isolates coded as ACT003, ACT004, ACT010, ACT013, ACT016, and ACT019 showed lipolytic activity on solid media with a respective diameter of 12 mm, 66 mm, 29 mm, 11 mm, 12 mm, and 10 mm. Based on 16S rRNA gene sequencing and phylogenetic analysis, the isolates coded as ACT004 and ACT010 were identified as Bacillus sp. TTs1 and Bacillus sp. TTs2; and the nucleotide sequences were submitted to GenBank (NCBI) with the accession numbers MW556206 and MW556207, respectively. Bacillus sp. TTs1 showed the maximum lipase production of 641.25 U/mL at 72 h, under optimized conditions that included initial pH (5), inoculum size (2percent, v/v), incubation temperature (45 oC), agitation speed (140 rpm), CaCl2 (0.01percent, w/v), yeast extract (1percent, w/v), and tween-80 (10percent, v/v). Similarly, the lipase production by Bacillus sp. TTs2 peaked at 96 h with enzyme activity of 618.8 U/mL in improved fermentation conditions consisting of initial pH (5), inoculum size (2-8percent, v/v), incubation temperature (25 oC), agitation speed (180 rpm), CaCl2 (0.01percent, w/v), yeast extract and peptone (1percent, w/v), and tween-80 (10percent, v/v). The evaluation of chicken feather concentrations on free fatty acid liberation showed that 6-8percent (w/v) chicken feather was adequate with free fatty acids contents of 0.58percent and 0.86percent for Bacillus sp. TTs1 and Bacillus sp. TTs2, respectively. Both isolates' lipases showed remarkable catalytic efficiency at pH and temperature of 7 and 40oC, respectively. The comparative analysis of residual lipids between pre-and post-fermentation indicated a 39.9 ± 7.8percent and 51.2 ± 20.2percent hydrolysis efficiency for Bacillus sp. TTs1 and Bacillus sp. TTs2, respectively. This study's findings indicated the lipolytic potentials of Bacillus spp. and suggest the possibility of a full bio-based approach for chicken feather lipid removal in the valorization of chicken feathers. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
Electrochemical sensing based on functionalised carbon dots prepared by bottom-up approach
- Madikizela, Ziyanda https://orcid.org/0000-0003-0405-8464
- Authors: Madikizela, Ziyanda https://orcid.org/0000-0003-0405-8464
- Date: 2021-02
- Subjects: Electrochemical analysis , Electrodes, Carbon
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22545 , vital:52424
- Description: This research was aimed at preparing carbon dots using the microwave method as a bottomup synthetic approach. The prepared carbon dots were them to be used as an electrode modifier in electrochemical detection of metal ion. The structure of the carbon dots prepared were characterized using different techniques including the FTIR, TEM, UV-Vis, PL, XRD and Raman Spectroscopy. It was observed that the nanoparticles consisted of carboxylic acid, amine and alcohol functional groups at their core and surface. UV-Vis and PL revealed that the carbon dots absorb more light in the visible and ultraviolet region, and the sizes of the carbon dots prepared were less than 10 nm. The carbon dots were then utilized for electrochemical sensing of Cd2+ ion, which is considered as one of harmful heavy metal ion when not controlled. Glassy carbon electrode modified with the carbon dots was utilized for the detection of Cd2+ through square wave voltammetry. Effect of different experimental parameters was studied which include electrode preparation, frequency, and amplitude. The electrochemical characterization of the electrode was done using the cyclic voltammetry and electrochemical impedance spectroscopy (EIS), the modified electrode was found conductive with much improved electrochemical performances. The obtained detection limit for Cd2+ sensing was 9.39 ppb, the developed C-dots modified GCE electrode was also tested with tap water Cd2+ spiked solution to demonstrate its implementation in real sample analysis. , Thesis (MA) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Authors: Madikizela, Ziyanda https://orcid.org/0000-0003-0405-8464
- Date: 2021-02
- Subjects: Electrochemical analysis , Electrodes, Carbon
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22545 , vital:52424
- Description: This research was aimed at preparing carbon dots using the microwave method as a bottomup synthetic approach. The prepared carbon dots were them to be used as an electrode modifier in electrochemical detection of metal ion. The structure of the carbon dots prepared were characterized using different techniques including the FTIR, TEM, UV-Vis, PL, XRD and Raman Spectroscopy. It was observed that the nanoparticles consisted of carboxylic acid, amine and alcohol functional groups at their core and surface. UV-Vis and PL revealed that the carbon dots absorb more light in the visible and ultraviolet region, and the sizes of the carbon dots prepared were less than 10 nm. The carbon dots were then utilized for electrochemical sensing of Cd2+ ion, which is considered as one of harmful heavy metal ion when not controlled. Glassy carbon electrode modified with the carbon dots was utilized for the detection of Cd2+ through square wave voltammetry. Effect of different experimental parameters was studied which include electrode preparation, frequency, and amplitude. The electrochemical characterization of the electrode was done using the cyclic voltammetry and electrochemical impedance spectroscopy (EIS), the modified electrode was found conductive with much improved electrochemical performances. The obtained detection limit for Cd2+ sensing was 9.39 ppb, the developed C-dots modified GCE electrode was also tested with tap water Cd2+ spiked solution to demonstrate its implementation in real sample analysis. , Thesis (MA) -- Faculty of Science and Agriculture, 2021
- Full Text:
Investigations of water deficit interactions with heat and elevated carbon dioxide in wheat
- Authors: Mavindidze, Peter
- Date: 2021-02
- Subjects: Plants--Effect of heat on , Growth (Plants)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20664 , vital:46422
- Description: Future climate is predicted to be characterised by elevated carbon dioxide (eCO2), as well as more incidences of heat and water deficit. eCO2 has been widely reported as enhancing growth, biomass and grain yield. To investigate the interactive effects of abiotic stresses on genotypic performance, an experiment was established in open-top chambers at the University of Rhodes eCO2 facility in Grahamstown, South Africa. The specific objectives of the study were: i) to evaluate the effects of eCO2 on wheat grain yield, yield components and grain quality under heat and terminal water deficit conditions; ii) to identify cultivar sources of tolerance to combined water deficit and heat stress under eCO2; iii) to identify appropriate stress indices that can be used as screening tools for tolerance to combined effects of water deficit and heat stress under eCO2. A total of 19 wheat genotypes were evaluated in three environments varying in CO2, temperature and water deficit during the 2019 winter season. The experiment was laid out in a split-split plot design arranged in blocks inside the chambers. The parameters recorded were: leaf water potential (LWP), biomass content (TB), number of productive tillers (NPT), days to flowering (DTA), days to maturity (DTM), plant height (PH), thousand kernel weight (TKW), number of kernels per spike (KPS), kernel weight per spike (KWS) and total grain weight (TGW). The following stress indices were determined: tolerance index, stress tolerance, yield susceptibility index, mean productivity, geometric mean productivity, stress intensity index and yield index. Elevated atmospheric CO2 ameliorated the negative effects of combined heat and water deficit stress by enhancing LWP, NPT, KPS, TB and TGW. Wheat genotypes responded the same way to CO2 with respect to grain yield. Furthermore, adequate water supply mitigated the adverse effects of heat stress. In addition, the combined effects of eCO2, heat and water deficit are confounding and hypo-additive in nature. The separation of environmental effects revealed that significant genotypic responses on grain yield and biomass were caused by heat and water deficit stress, while eCO2 mitigated their negative effects, promoting growth and reproduction. Both Principal component analysis (PCA) biplot analysis and cultivar superiority measure proved to be reliable statistical tools since they managed to identify 13-5HTSBWYT-H18, Ncema and SST8135 as having both specific adaptations to future climates as well as wide adaption to multiple environments. The genotypes may be used as sources (parents for crosses) for wide adaptation in breeding programmes in the wake of predicted future climate environments. PCA biplot analysis identified mean productivity (MP) and geometric mean productivity (GMP) as the best indices; hence can also be as secondary traits complimenting traditional agronomic and physiological traits in wheat breeding under environments varying in water availability, CO2 and temperature. The interactive effects of eCO2 with heat and water deficit stress did not significantly compromise the grain physical characteristics, flour extraction, protein content, falling number and flour ash. eCO2 ameliorated the negative effects of heat and water deficit by increasing protein content by 4.75 percent , Thesis (MSc) (Crop Science) -- University of Fort Hare, 2021
- Full Text:
- Authors: Mavindidze, Peter
- Date: 2021-02
- Subjects: Plants--Effect of heat on , Growth (Plants)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20664 , vital:46422
- Description: Future climate is predicted to be characterised by elevated carbon dioxide (eCO2), as well as more incidences of heat and water deficit. eCO2 has been widely reported as enhancing growth, biomass and grain yield. To investigate the interactive effects of abiotic stresses on genotypic performance, an experiment was established in open-top chambers at the University of Rhodes eCO2 facility in Grahamstown, South Africa. The specific objectives of the study were: i) to evaluate the effects of eCO2 on wheat grain yield, yield components and grain quality under heat and terminal water deficit conditions; ii) to identify cultivar sources of tolerance to combined water deficit and heat stress under eCO2; iii) to identify appropriate stress indices that can be used as screening tools for tolerance to combined effects of water deficit and heat stress under eCO2. A total of 19 wheat genotypes were evaluated in three environments varying in CO2, temperature and water deficit during the 2019 winter season. The experiment was laid out in a split-split plot design arranged in blocks inside the chambers. The parameters recorded were: leaf water potential (LWP), biomass content (TB), number of productive tillers (NPT), days to flowering (DTA), days to maturity (DTM), plant height (PH), thousand kernel weight (TKW), number of kernels per spike (KPS), kernel weight per spike (KWS) and total grain weight (TGW). The following stress indices were determined: tolerance index, stress tolerance, yield susceptibility index, mean productivity, geometric mean productivity, stress intensity index and yield index. Elevated atmospheric CO2 ameliorated the negative effects of combined heat and water deficit stress by enhancing LWP, NPT, KPS, TB and TGW. Wheat genotypes responded the same way to CO2 with respect to grain yield. Furthermore, adequate water supply mitigated the adverse effects of heat stress. In addition, the combined effects of eCO2, heat and water deficit are confounding and hypo-additive in nature. The separation of environmental effects revealed that significant genotypic responses on grain yield and biomass were caused by heat and water deficit stress, while eCO2 mitigated their negative effects, promoting growth and reproduction. Both Principal component analysis (PCA) biplot analysis and cultivar superiority measure proved to be reliable statistical tools since they managed to identify 13-5HTSBWYT-H18, Ncema and SST8135 as having both specific adaptations to future climates as well as wide adaption to multiple environments. The genotypes may be used as sources (parents for crosses) for wide adaptation in breeding programmes in the wake of predicted future climate environments. PCA biplot analysis identified mean productivity (MP) and geometric mean productivity (GMP) as the best indices; hence can also be as secondary traits complimenting traditional agronomic and physiological traits in wheat breeding under environments varying in water availability, CO2 and temperature. The interactive effects of eCO2 with heat and water deficit stress did not significantly compromise the grain physical characteristics, flour extraction, protein content, falling number and flour ash. eCO2 ameliorated the negative effects of heat and water deficit by increasing protein content by 4.75 percent , Thesis (MSc) (Crop Science) -- University of Fort Hare, 2021
- Full Text:
Keratinous poultry waste valorization through novel keratinases of C. cucumeris and S. multivorium isolated from poultry sludge
- Authors: Qaphela, Hendrick
- Date: 2021-02
- Subjects: Food--Biotechnology , Poultry , Poultry industry
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20860 , vital:46640
- Description: Annually, about 55 percent of keratinous wastes are generated from various agro-industrial processing farms in South Africa. These wastes are difficult to handle due to structural integrity; hence, they constitute environmental issues due to the disposal means. Degradation of keratinous wastes using microbial-based technology has been deemed advantageous as it generates products with high-end values. Therefore, in this study, chicken feather and soil samples were collected from a local poultry farm, and bacteria were isolated using basal salt media supplemented with chicken feathers. The isolates were evaluated for proteolytic and keratinolytic potentials. The potent isolates were identified through 16S rDNA sequence and phylogenetic analysis. Fermentation media were optimized for enhanced keratinase production, and the amino acids liberated in the media during feather biodegradation were quantified. The biochemical properties of the keratinases produced were likewise determined. Ten (10) proteolytic bacteria were obtained from 20 isolates recovered from the samples with a diameter of halo on skimmed milk agar plate ranging from 15.5 ± 0.71 (mm) for isolate coded as PSW-15 to 28 ± 1.41 (mm) for isolate coded as PSW-08. The proteolytic bacteria showed variable keratinolytic potentials with percentage feather degradation that ranged from 29 percent for PSW-11 to 84 percent for PSW-14, and keratinase activity ranging from 99.99 U/mL for PSW-15 to 761.82 U/mL for PSW-14. The most potent isolates coded as PSW-14 and PSW-16 were identified as Chryseobacterium cucumeris FHN1 and Sphingobacterium multivorum HNFx. Their nucleotide sequences were submitted to the GenBank as MW16587 and MK82939, respectively. The optimization of fermentation conditions; C. cucumeris FHN1 showed improved activity at pH 5 - 6, inoculum size (4 percent, v/v), chicken feather concentration (1 percent, w/v), fermentation temperature (25o C). Similarly, S. multivorum HNFx showed optimal activity at pH 4.0, inoculum size (5 percent, v/v), chicken feather concentration (2.5 percent, w/v), and fermentation temperature (25-30 oC). C. cucumeris FHN1 and S. multivorum HNFx showed maximum keratinase production of 485.54 U/mL and 526.36 U/mL at 96 h and 72 h of incubation period respectively. Serine, aspartic acid, glutamic acid, and proline were the most abundant amino acids in the degraded chicken feathers, and upon quantitation, the following concentration was respectively obtained; 3.71, 3.4, 4.19 and 4.35 (g/100g sample) against C. cucumeris FHN1. While S. multivorum HNFx yielded aspartic acid (2.04 g/100g sample) and glutamic acid (2.0 g/100g sample) in high concentration. The keratinases showed optimal catalytic efficiency at pH and temperature of 8.0 and 90 oC, respectively. C. cucumeris FHN1 keratinase was inhibited by metal ion chelating agents; EDTA and 1,10-phenanthroline, suggesting a metallo-type of protease. The enzyme showed remarkable stability after pre-treatment with DTT, Fe2+, Fe3+ and Cu2+, with respective residual activity of 108 percent, 102 percent, 114 percent, and 104 percent. The S. multivorum HNFx keratinase; activity was not inhibited by serine- and metallo-protease inhibitors. It maintained the following residual activity against the following chemical agents; DTT (124 percent), hydrogen peroxide (152 percent), DMSO (161 percent), triton X-100 (152 percent), tween-80 (101 percent), and metal ions; Fe2+ (128 percent), Fe3+ (104 percent), K+ (117 percent), Ca2+ (104 percent), Na+ (103 percent), Ba2+ (115 percent), Al3+ (126 percent). The enzyme showed a substantial loss of catalytic efficiency after pre-incubation with various laundry detergents. The keratinases' remarkable stability in the presence of various chemical agents and metal ions tested suggests biotechnological and industrial application potentials. Consequently, the isolates portend industrial relevance for keratinous waste valorization and an excellent source of keratinases of industrial relevance. , Thesis (MSc) (Microbiology) -- University of Fort Hare, 2021
- Full Text:
- Authors: Qaphela, Hendrick
- Date: 2021-02
- Subjects: Food--Biotechnology , Poultry , Poultry industry
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20860 , vital:46640
- Description: Annually, about 55 percent of keratinous wastes are generated from various agro-industrial processing farms in South Africa. These wastes are difficult to handle due to structural integrity; hence, they constitute environmental issues due to the disposal means. Degradation of keratinous wastes using microbial-based technology has been deemed advantageous as it generates products with high-end values. Therefore, in this study, chicken feather and soil samples were collected from a local poultry farm, and bacteria were isolated using basal salt media supplemented with chicken feathers. The isolates were evaluated for proteolytic and keratinolytic potentials. The potent isolates were identified through 16S rDNA sequence and phylogenetic analysis. Fermentation media were optimized for enhanced keratinase production, and the amino acids liberated in the media during feather biodegradation were quantified. The biochemical properties of the keratinases produced were likewise determined. Ten (10) proteolytic bacteria were obtained from 20 isolates recovered from the samples with a diameter of halo on skimmed milk agar plate ranging from 15.5 ± 0.71 (mm) for isolate coded as PSW-15 to 28 ± 1.41 (mm) for isolate coded as PSW-08. The proteolytic bacteria showed variable keratinolytic potentials with percentage feather degradation that ranged from 29 percent for PSW-11 to 84 percent for PSW-14, and keratinase activity ranging from 99.99 U/mL for PSW-15 to 761.82 U/mL for PSW-14. The most potent isolates coded as PSW-14 and PSW-16 were identified as Chryseobacterium cucumeris FHN1 and Sphingobacterium multivorum HNFx. Their nucleotide sequences were submitted to the GenBank as MW16587 and MK82939, respectively. The optimization of fermentation conditions; C. cucumeris FHN1 showed improved activity at pH 5 - 6, inoculum size (4 percent, v/v), chicken feather concentration (1 percent, w/v), fermentation temperature (25o C). Similarly, S. multivorum HNFx showed optimal activity at pH 4.0, inoculum size (5 percent, v/v), chicken feather concentration (2.5 percent, w/v), and fermentation temperature (25-30 oC). C. cucumeris FHN1 and S. multivorum HNFx showed maximum keratinase production of 485.54 U/mL and 526.36 U/mL at 96 h and 72 h of incubation period respectively. Serine, aspartic acid, glutamic acid, and proline were the most abundant amino acids in the degraded chicken feathers, and upon quantitation, the following concentration was respectively obtained; 3.71, 3.4, 4.19 and 4.35 (g/100g sample) against C. cucumeris FHN1. While S. multivorum HNFx yielded aspartic acid (2.04 g/100g sample) and glutamic acid (2.0 g/100g sample) in high concentration. The keratinases showed optimal catalytic efficiency at pH and temperature of 8.0 and 90 oC, respectively. C. cucumeris FHN1 keratinase was inhibited by metal ion chelating agents; EDTA and 1,10-phenanthroline, suggesting a metallo-type of protease. The enzyme showed remarkable stability after pre-treatment with DTT, Fe2+, Fe3+ and Cu2+, with respective residual activity of 108 percent, 102 percent, 114 percent, and 104 percent. The S. multivorum HNFx keratinase; activity was not inhibited by serine- and metallo-protease inhibitors. It maintained the following residual activity against the following chemical agents; DTT (124 percent), hydrogen peroxide (152 percent), DMSO (161 percent), triton X-100 (152 percent), tween-80 (101 percent), and metal ions; Fe2+ (128 percent), Fe3+ (104 percent), K+ (117 percent), Ca2+ (104 percent), Na+ (103 percent), Ba2+ (115 percent), Al3+ (126 percent). The enzyme showed a substantial loss of catalytic efficiency after pre-incubation with various laundry detergents. The keratinases' remarkable stability in the presence of various chemical agents and metal ions tested suggests biotechnological and industrial application potentials. Consequently, the isolates portend industrial relevance for keratinous waste valorization and an excellent source of keratinases of industrial relevance. , Thesis (MSc) (Microbiology) -- University of Fort Hare, 2021
- Full Text:
Keratinous poultry wastes valorization through novel keratinases of Chryseobacterium cucumeris and Sphingobacterium multivorum isolated from poultry sludge
- Hendrick, Qaphela https://orcid.org/0000-0001-7529-8129
- Authors: Hendrick, Qaphela https://orcid.org/0000-0001-7529-8129
- Date: 2021-02
- Subjects: Agricultural wastes , Factory and trade waste
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21400 , vital:48537
- Description: Annually, about 55percent of keratinous wastes are generated from various agro-industrial processing farms in South Africa. These wastes are difficult to handle due to structural integrity; hence, they constitute environmental issues due to the disposal means. Degradation of keratinous wastes using microbial-based technology has been deemed advantageous as it generates products with high-end values. Therefore, in this study, chicken feather and soil samples were collected from a local poultry farm, and bacteria were isolated using basal salt media supplemented with chicken feathers. The isolates were evaluated for proteolytic and keratinolytic potentials. The potent isolates were identified through 16S rDNA sequence and phylogenetic analysis. Fermentation media were optimized for enhanced keratinase production, and the amino acids liberated in the media during feather biodegradation were quantified. The biochemical properties of the keratinases produced were likewise determined. Ten (10) proteolytic bacteria were obtained from 20 isolates recovered from the samples with a diameter of halo on skimmed milk agar plate ranging from 15.5 ± 0.71 (mm) for isolate coded as PSW-15 to 28 ± 1.41 (mm) for isolate coded as PSW-08. The proteolytic bacteria showed variable keratinolytic potentials with percentage feather degradation that ranged from 29percent for PSW-11 to 84percent for PSW-14, and keratinase activity ranging from 99.99 U/mL for PSW-15 to 761.82 U/mL for PSW-14. The most potent isolates coded as PSW-14 and PSW-16 were identified as Chryseobacterium cucumeris FHN1 and Sphingobacterium multivorum HNFx. Their nucleotide sequences were submitted to the GenBank as MW16587 and MK82939, respectively. The optimization of fermentation conditions; C. cucumeris FHN1 showed improved activity at pH 5 - 6, inoculum size (4percent, v/v), chicken feather concentration (1percent, w/v), fermentation temperature (25o C). Similarly, S. multivorum HNFx showed optimal activity at pH 4.0, inoculum size (5percent, v/v), chicken feather concentration (2.5percent, w/v), and fermentation temperature (25-30 oC). C. cucumeris FHN1 and S. multivorum HNFx showed maximum keratinase production of 485.54 U/mL and 526.36 U/mL at 96 h and 72 h of incubation period respectively. Serine, aspartic acid, glutamic acid, and proline were the most abundant amino acids in the degraded chicken feathers, and upon quantitation, the following concentration was respectively obtained; 3.71, 3.4, 4.19 and 4.35 (g/100g sample) against C. cucumeris FHN1. While S. multivorum HNFx yielded aspartic acid (2.04 g/100g sample) and glutamic acid (2.0 g/100g sample) in high concentration. The keratinases showed optimal catalytic efficiency at pH and temperature of 8.0 and 90 oC, respectively. C. cucumeris FHN1 keratinase was inhibited by metal ion chelating agents; EDTA and 1,10-phenanthroline, suggesting a metallo-type of protease. The enzyme showed remarkable stability after pre-treatment with DTT, Fe2+, Fe3+ and Cu2+, with respective residual activity of 108percent, 102percent, 114percent, and 104percent. The S. multivorum HNFx keratinase; activity was not inhibited by serine- and metallo-protease inhibitors. It maintained the following residual activity against the following chemical agents; DTT (124percent), hydrogen peroxide (152percent), DMSO (161percent), triton X-100 (152percent), tween-80 (101percent), and metal ions; Fe2+ (128percent), Fe3+ (104percent), K+ (117percent), Ca2+ (104percent), Na+ (103percent), Ba2+ (115percent), Al3+ (126percent). The enzyme showed a substantial loss of catalytic efficiency after pre-incubation with various laundry detergents. The keratinases' remarkable stability in the presence of various chemical agents and metal ions tested suggests biotechnological and industrial application potentials. Consequently, the isolates portend industrial relevance for keratinous waste valorization and an excellent source of keratinases of industrial relevance. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Authors: Hendrick, Qaphela https://orcid.org/0000-0001-7529-8129
- Date: 2021-02
- Subjects: Agricultural wastes , Factory and trade waste
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21400 , vital:48537
- Description: Annually, about 55percent of keratinous wastes are generated from various agro-industrial processing farms in South Africa. These wastes are difficult to handle due to structural integrity; hence, they constitute environmental issues due to the disposal means. Degradation of keratinous wastes using microbial-based technology has been deemed advantageous as it generates products with high-end values. Therefore, in this study, chicken feather and soil samples were collected from a local poultry farm, and bacteria were isolated using basal salt media supplemented with chicken feathers. The isolates were evaluated for proteolytic and keratinolytic potentials. The potent isolates were identified through 16S rDNA sequence and phylogenetic analysis. Fermentation media were optimized for enhanced keratinase production, and the amino acids liberated in the media during feather biodegradation were quantified. The biochemical properties of the keratinases produced were likewise determined. Ten (10) proteolytic bacteria were obtained from 20 isolates recovered from the samples with a diameter of halo on skimmed milk agar plate ranging from 15.5 ± 0.71 (mm) for isolate coded as PSW-15 to 28 ± 1.41 (mm) for isolate coded as PSW-08. The proteolytic bacteria showed variable keratinolytic potentials with percentage feather degradation that ranged from 29percent for PSW-11 to 84percent for PSW-14, and keratinase activity ranging from 99.99 U/mL for PSW-15 to 761.82 U/mL for PSW-14. The most potent isolates coded as PSW-14 and PSW-16 were identified as Chryseobacterium cucumeris FHN1 and Sphingobacterium multivorum HNFx. Their nucleotide sequences were submitted to the GenBank as MW16587 and MK82939, respectively. The optimization of fermentation conditions; C. cucumeris FHN1 showed improved activity at pH 5 - 6, inoculum size (4percent, v/v), chicken feather concentration (1percent, w/v), fermentation temperature (25o C). Similarly, S. multivorum HNFx showed optimal activity at pH 4.0, inoculum size (5percent, v/v), chicken feather concentration (2.5percent, w/v), and fermentation temperature (25-30 oC). C. cucumeris FHN1 and S. multivorum HNFx showed maximum keratinase production of 485.54 U/mL and 526.36 U/mL at 96 h and 72 h of incubation period respectively. Serine, aspartic acid, glutamic acid, and proline were the most abundant amino acids in the degraded chicken feathers, and upon quantitation, the following concentration was respectively obtained; 3.71, 3.4, 4.19 and 4.35 (g/100g sample) against C. cucumeris FHN1. While S. multivorum HNFx yielded aspartic acid (2.04 g/100g sample) and glutamic acid (2.0 g/100g sample) in high concentration. The keratinases showed optimal catalytic efficiency at pH and temperature of 8.0 and 90 oC, respectively. C. cucumeris FHN1 keratinase was inhibited by metal ion chelating agents; EDTA and 1,10-phenanthroline, suggesting a metallo-type of protease. The enzyme showed remarkable stability after pre-treatment with DTT, Fe2+, Fe3+ and Cu2+, with respective residual activity of 108percent, 102percent, 114percent, and 104percent. The S. multivorum HNFx keratinase; activity was not inhibited by serine- and metallo-protease inhibitors. It maintained the following residual activity against the following chemical agents; DTT (124percent), hydrogen peroxide (152percent), DMSO (161percent), triton X-100 (152percent), tween-80 (101percent), and metal ions; Fe2+ (128percent), Fe3+ (104percent), K+ (117percent), Ca2+ (104percent), Na+ (103percent), Ba2+ (115percent), Al3+ (126percent). The enzyme showed a substantial loss of catalytic efficiency after pre-incubation with various laundry detergents. The keratinases' remarkable stability in the presence of various chemical agents and metal ions tested suggests biotechnological and industrial application potentials. Consequently, the isolates portend industrial relevance for keratinous waste valorization and an excellent source of keratinases of industrial relevance. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
Synthesis and characterization of molybdenum dichalcogenides nanoparticles via solution-processed technique for photovoltaic applications
- Authors: Shelter, Chikukwa Evernice
- Date: 2021-02
- Subjects: Nanoparticles , Colloids
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20653 , vital:46417
- Description: Energy generated from non-renewable energy sources has a drawback of prompted outflow of ozone harming substances. These drawbacks of the non-renewable energy have quickened innovative work of renewable power sources, since they have an advantage of the provision of a better, preserved, decent environment that is free from natural contamination and commotion. Photovoltaic devices are prevalent in improving the green energy utilization and defeating the natural concerns yielded from the current most overwhelming energy sources. Herein, the synthesis, characterization, and application of Molybdenum chalcogenide nanoparticles (NP) as alternative sources in the absorber layer of quantum dot solar sensitized cells (QDSSCs) is discussed. The MoS2 NPs were synthesized from the aliphatic and aromatic dithiocarbamate (DTC) ligands and complexes as precursors. The successful synthesis of the DTC ligands and MoDTC complexes was confirmed through characterization with a variety of techniques including 1H and 13C-NMR, Raman Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-visible spectroscopy (UV-VIS), Thermogravimetric analysis (TGA) and Derivative thermogravimetric (DTG) analysis. The synthesized MoDTC complexes (precursors) were further used in the synthesis of MoS2 nanoparticles. A bottom -up colloidal approach was employed for the synthesis of the MoX2 NPs. The successful synthesis of the NP was confirmed as the results from the diffractive peaks obtained from XRD which were positive and agreed in comparison with the standard. The diffractive peaks were shown in the planes (100), (002), (100) and (105) for MoS2 nanoparticles; (002), (100), (103) and (110) for MoSe2 and (0002), (0004), (103) as well as (0006) for the MoTe2 nanoparticles. The MoSe2 nanoparticles showed the least size of the nanoparticles followed by MoTe2 and lastly MoS2. These results agreed with the results obtained using SEM analysis. For the optical properties of the nanoparticles, UV-VIS and PL were used, the shift of the peaks from the red shift (600 nm) to the blue shift 270-5 nm and 287-9 nm (UV-VIS) confirmed that the nanoparticles were quantum confined. The application of the MoX2 NPs in QDSSCs was done with MoSe2 showing the greatest PCE of 7.86 percent followed by MoTe2 6.93 percent and lastly MoS2 with a PCE of 6.05 percent and 5.47 percent. , Thesis (MSc) (Chemistry) -- University of Fort Hare, 2021
- Full Text:
- Authors: Shelter, Chikukwa Evernice
- Date: 2021-02
- Subjects: Nanoparticles , Colloids
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20653 , vital:46417
- Description: Energy generated from non-renewable energy sources has a drawback of prompted outflow of ozone harming substances. These drawbacks of the non-renewable energy have quickened innovative work of renewable power sources, since they have an advantage of the provision of a better, preserved, decent environment that is free from natural contamination and commotion. Photovoltaic devices are prevalent in improving the green energy utilization and defeating the natural concerns yielded from the current most overwhelming energy sources. Herein, the synthesis, characterization, and application of Molybdenum chalcogenide nanoparticles (NP) as alternative sources in the absorber layer of quantum dot solar sensitized cells (QDSSCs) is discussed. The MoS2 NPs were synthesized from the aliphatic and aromatic dithiocarbamate (DTC) ligands and complexes as precursors. The successful synthesis of the DTC ligands and MoDTC complexes was confirmed through characterization with a variety of techniques including 1H and 13C-NMR, Raman Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-visible spectroscopy (UV-VIS), Thermogravimetric analysis (TGA) and Derivative thermogravimetric (DTG) analysis. The synthesized MoDTC complexes (precursors) were further used in the synthesis of MoS2 nanoparticles. A bottom -up colloidal approach was employed for the synthesis of the MoX2 NPs. The successful synthesis of the NP was confirmed as the results from the diffractive peaks obtained from XRD which were positive and agreed in comparison with the standard. The diffractive peaks were shown in the planes (100), (002), (100) and (105) for MoS2 nanoparticles; (002), (100), (103) and (110) for MoSe2 and (0002), (0004), (103) as well as (0006) for the MoTe2 nanoparticles. The MoSe2 nanoparticles showed the least size of the nanoparticles followed by MoTe2 and lastly MoS2. These results agreed with the results obtained using SEM analysis. For the optical properties of the nanoparticles, UV-VIS and PL were used, the shift of the peaks from the red shift (600 nm) to the blue shift 270-5 nm and 287-9 nm (UV-VIS) confirmed that the nanoparticles were quantum confined. The application of the MoX2 NPs in QDSSCs was done with MoSe2 showing the greatest PCE of 7.86 percent followed by MoTe2 6.93 percent and lastly MoS2 with a PCE of 6.05 percent and 5.47 percent. , Thesis (MSc) (Chemistry) -- University of Fort Hare, 2021
- Full Text:
The acoustic niche and conservation status of the recently described Hogsback caco, Cacosternum thorini (Amphibia: Pyxicephalidae), Hogsback, Eastern Cape, South Africa
- Authors: Kom, Nokuthula
- Date: 2021-02
- Subjects: Amphibians
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20429 , vital:45665
- Description: Animals may compete for acoustic space (acoustic niche) in the same way they do for habitat space. The most intense competition involves individuals with the most similar resource requirements (i.e. conspecifics), but if competition is interspecific, then mate recognition must occur both within and between species. The coexistence of the bronze caco (Cacosternum nanum) and the Hogsback caco (C. thorini) in the Tor Doone area of Hogsback could be interpreted as a result of past competition, which drove acoustic partitioning by means of the evolution of specific calls that do not overlap in frequency. Frogs are known to coexist well with other frog species because of their highly specific advertisement calls, which differ even between closely related species. One of the main aims of the project was to record and provide a description of the call of the recently described Hogsback caco, C. thorini. I identified 30 calling males and recorded each for 10 min in February 2016, yielding a total of 235 calls. Summary values for the calls include duration of 40 ± 14 ms, with 16 ± 5 pulses produced at a pulse-rate of 46 ± 21 s-1 and a mean dominant frequency of 4.19 ± 0.58 kHz. The call of C. thorini differs from those of all other cacos, by its incremental structure (increased number of pulses within consecutive units). My second goal was to use playbacks to investigate the preferred habitat of C. thorini and to compare it with that of C. nanum. I conducted experiments to measure the propagation of C. thorini and C. nanum calls in three different habitats (C. thorini habitat, C. nanum habitat, and grassland with no water bodies). Finally, I investigated the effect of drought and flood on the pools used by males as calling sites, using a buried basin to which I added water in 10 litre aliquots. The optimal water level for call propagation in the artificial pools was half-full. Using playbacks, I tested whether the two species responded to each other’s calls. I found that, although the two species call at the same time and each call in response to the other’s calls, they do not recognise heterospecific calls; they simply respond to noise. I found no evidence of acoustic competition between the two species, and in fact, the abundant, dominant species, C. nanum, was rare in the C. thorini preferred habitat. The results of this study may assist efforts to conserve endemic amphibians in the Amatola Mountains. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Authors: Kom, Nokuthula
- Date: 2021-02
- Subjects: Amphibians
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20429 , vital:45665
- Description: Animals may compete for acoustic space (acoustic niche) in the same way they do for habitat space. The most intense competition involves individuals with the most similar resource requirements (i.e. conspecifics), but if competition is interspecific, then mate recognition must occur both within and between species. The coexistence of the bronze caco (Cacosternum nanum) and the Hogsback caco (C. thorini) in the Tor Doone area of Hogsback could be interpreted as a result of past competition, which drove acoustic partitioning by means of the evolution of specific calls that do not overlap in frequency. Frogs are known to coexist well with other frog species because of their highly specific advertisement calls, which differ even between closely related species. One of the main aims of the project was to record and provide a description of the call of the recently described Hogsback caco, C. thorini. I identified 30 calling males and recorded each for 10 min in February 2016, yielding a total of 235 calls. Summary values for the calls include duration of 40 ± 14 ms, with 16 ± 5 pulses produced at a pulse-rate of 46 ± 21 s-1 and a mean dominant frequency of 4.19 ± 0.58 kHz. The call of C. thorini differs from those of all other cacos, by its incremental structure (increased number of pulses within consecutive units). My second goal was to use playbacks to investigate the preferred habitat of C. thorini and to compare it with that of C. nanum. I conducted experiments to measure the propagation of C. thorini and C. nanum calls in three different habitats (C. thorini habitat, C. nanum habitat, and grassland with no water bodies). Finally, I investigated the effect of drought and flood on the pools used by males as calling sites, using a buried basin to which I added water in 10 litre aliquots. The optimal water level for call propagation in the artificial pools was half-full. Using playbacks, I tested whether the two species responded to each other’s calls. I found that, although the two species call at the same time and each call in response to the other’s calls, they do not recognise heterospecific calls; they simply respond to noise. I found no evidence of acoustic competition between the two species, and in fact, the abundant, dominant species, C. nanum, was rare in the C. thorini preferred habitat. The results of this study may assist efforts to conserve endemic amphibians in the Amatola Mountains. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
The optimisation of transportation methods for abalone (Haliotis midae Linnaeus, 1758 (Mollusca: Gastropoda)) larvae
- Authors: Bajaba, Sharone
- Date: 2021-02
- Subjects: Abalone fisheries , Haliotis midae , Abalone culture
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20561 , vital:46124
- Description: Sea ranching has been identified as a viable method for enhancing the natural stock of overexploited abalone (Haliotis midae). Currently, this process involves transporting live juvenile H. midae to the seeding site where they are released onto the reef however this is both costly and logistically problematic. Transportation of abalone larvae is another cost-effective option, as they are cheaper to produce and can be transported at high densities. A suitable larval transport method is required to minimise larval mortalities and stresses that might compromise settlement. A series of simulated experiments were conducted to optimise transportation systems of abalone (Haliotis midae) larvae. First, two potential transportation modes (Wet (W) and Dry (D) transportation) conducted at a cooler (14˚C) and average ambient (18˚C) temperatures with six replicates of each were compared with control treatments (six replicates) that were not subjected to transport, kept in water at 18˚C. Eighty hours post-initial settlement, the 14W treatment had significantly lower settlement (p=0.03) than the other three treatments (14D, 18W, 18D) and the Control. The Dry method was the prefered method to transport larvae as it is logistically simpler to employ. The second experiment investigated the effect of different stocking densities (200, 400 and 800 larvae cm-2) for the Dry method 18˚C over two transit periods (six and twelve hours) on post-transport settlement and post-settlement survival of H. midae larvae. Compared to the control, there was no difference in the number of settled larvae (p=0.368) and larvae still swimming (p=0.835) across all treatments. This suggested that H. midae larvae can be transported for twelve hours at 800 larvae cm-2 without compromising post-transport settlement or survival. This study’s results and recommendations can be used by abalone farms when there is a need to move abalone H. midae larvae between farms or to seeding sites for sea ranching. Furthermore, other researchers can use these results as a benchmark for larval transportation studies of H. midae and other abalone species. , Thesis (MSc) (Zoology) -- University of Fort Hare, 2021
- Full Text:
- Authors: Bajaba, Sharone
- Date: 2021-02
- Subjects: Abalone fisheries , Haliotis midae , Abalone culture
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20561 , vital:46124
- Description: Sea ranching has been identified as a viable method for enhancing the natural stock of overexploited abalone (Haliotis midae). Currently, this process involves transporting live juvenile H. midae to the seeding site where they are released onto the reef however this is both costly and logistically problematic. Transportation of abalone larvae is another cost-effective option, as they are cheaper to produce and can be transported at high densities. A suitable larval transport method is required to minimise larval mortalities and stresses that might compromise settlement. A series of simulated experiments were conducted to optimise transportation systems of abalone (Haliotis midae) larvae. First, two potential transportation modes (Wet (W) and Dry (D) transportation) conducted at a cooler (14˚C) and average ambient (18˚C) temperatures with six replicates of each were compared with control treatments (six replicates) that were not subjected to transport, kept in water at 18˚C. Eighty hours post-initial settlement, the 14W treatment had significantly lower settlement (p=0.03) than the other three treatments (14D, 18W, 18D) and the Control. The Dry method was the prefered method to transport larvae as it is logistically simpler to employ. The second experiment investigated the effect of different stocking densities (200, 400 and 800 larvae cm-2) for the Dry method 18˚C over two transit periods (six and twelve hours) on post-transport settlement and post-settlement survival of H. midae larvae. Compared to the control, there was no difference in the number of settled larvae (p=0.368) and larvae still swimming (p=0.835) across all treatments. This suggested that H. midae larvae can be transported for twelve hours at 800 larvae cm-2 without compromising post-transport settlement or survival. This study’s results and recommendations can be used by abalone farms when there is a need to move abalone H. midae larvae between farms or to seeding sites for sea ranching. Furthermore, other researchers can use these results as a benchmark for larval transportation studies of H. midae and other abalone species. , Thesis (MSc) (Zoology) -- University of Fort Hare, 2021
- Full Text:
The Relationship Between Food Sharing and Social Cohesion among Local Farmers: a case study of Ntafufu Location, Port St Johns Municipality.
- Mphompo, Aphiwe (https://orcid.org/ 0000-0003-0370-8007)
- Authors: Mphompo, Aphiwe (https://orcid.org/ 0000-0003-0370-8007)
- Date: 2021-02
- Subjects: Food supply , Social integration , Food relief
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20981 , vital:46876
- Description: The overall aim of this study was to examine how food sharing at Ntafufu location in Port St Johns (Republic of South Africa), augments social cohesion among local farmers. A mixed-method approach was used for this study. This study used a triangulation research method to measure the correlation between food sharing and social cohesion and to ensure that it is statistically sound, certainly gaining rich data from the study population. Focus groups and questionnaires were used to collect data. The researcher used thematic analysis for qualitative analysis and Statistical Packages for the Social Science (SPSS) for quantitative analysis. The researcher did not include the whole population. The researcher only interviewed selected participants, and these participants were taken from the study population. There were 13 participants for qualitative research and 43 participants for quantitative research totalling 56 participants. The findings revealed that there is a relationship between food sharing and social cohesion. An important finding to emerge in this study is that food sharing alleviates poverty. However, several limitations need to be considered. For instance, witchcraft was mentioned as a challenge for this practice. , Thesis (MSoc) (Anthropology) -- University of Fort Hare, 2021
- Full Text:
- Authors: Mphompo, Aphiwe (https://orcid.org/ 0000-0003-0370-8007)
- Date: 2021-02
- Subjects: Food supply , Social integration , Food relief
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20981 , vital:46876
- Description: The overall aim of this study was to examine how food sharing at Ntafufu location in Port St Johns (Republic of South Africa), augments social cohesion among local farmers. A mixed-method approach was used for this study. This study used a triangulation research method to measure the correlation between food sharing and social cohesion and to ensure that it is statistically sound, certainly gaining rich data from the study population. Focus groups and questionnaires were used to collect data. The researcher used thematic analysis for qualitative analysis and Statistical Packages for the Social Science (SPSS) for quantitative analysis. The researcher did not include the whole population. The researcher only interviewed selected participants, and these participants were taken from the study population. There were 13 participants for qualitative research and 43 participants for quantitative research totalling 56 participants. The findings revealed that there is a relationship between food sharing and social cohesion. An important finding to emerge in this study is that food sharing alleviates poverty. However, several limitations need to be considered. For instance, witchcraft was mentioned as a challenge for this practice. , Thesis (MSoc) (Anthropology) -- University of Fort Hare, 2021
- Full Text:
Valorization of chicken feather through dekeratinization by keratinolytic Bacillus species to amino acid
- Authors: Matches, Lupho
- Date: 2021-02
- Subjects: Proteolytic enzymes , Poultry -- Processing
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20451 , vital:45667
- Description: The poultry meat processing sector generates chicken feathers as by-products, and they are 90percent keratin in composition. Keratin is an insoluble and structural protein that shows recalcitrance to hydrolysis by classical proteolytic enzymes, including trypsin, pepsin, and papain. Keratinases are a group of proteolytic enzymes endowed with keratin degradation into peptides and amino acids. They are recently gaining traction for their multifaceted potential application in the green industrial space. Hence, keratinolytic bacteria previously isolated from dumpsite were identified using 16S rDNA sequencing. The optimal fermentation conditions were determined for enhanced extracellular keratinase production and chicken feather degradation. Also, the amino acid analysis of the chicken feather hydrolysates was carried out. The biochemical properties of the keratinases were also determined. Based on 16S rDNA sequencing and phylogenetic analysis, the isolates coded as SSN-02 and HSN-03 showed a high percentage of sequence homology with Bacillus spp.; hence, they were identified as Bacillus sp. NFH5 and Bacillus sp. FHNM, respectively. Bacillus sp. NFH5 showed optimal keratinase production of 1149.99 ± 80.99 U/mL after 96 h of incubation time, in optimized fermentation conditions that included pH (4.0), chicken feather (1.5percent, w/v), inoculum size (3percent, v/v) and temperature (30 oC). Similarly, Bacillus sp. FHNM demonstrated the maximum keratinase production of 480 ± 41.14 U/mL 144 h post cultivation, in optimized fermentation conditions with pH (7.0), chicken feather (2.0percent, w/v), inoculum size (3percent, v/v) and temperature (30 oC). For Bacillus sp. NFH5 chicken feather hydrolysate, the amino acids in relatively higher concentration (>1.0g/100g sample) include arginine (1.8), serine (1.16), aspartic acid (1.95), glutamic acid (2.47), proline (1.16) and glycine (1.45). Bacillus sp. FHNM feather hydrolysates, contained (g/100g of sample): arginine (1.9), serine (1.4), aspartic acid (2.5), glutamic acid (2.51), glycine (1.51), proline (1.13), leucine (1.030, histidine (1.25), and lysine (1.06) (g/100g of sample) in high concentration. The keratinases were optimally active at pH 8.0. Bacillus sp. FHNM showed an optimal temperature of 100 oC; while Bacillus sp. NFH5 keratinase displayed optimal activity at 90 oC. EDTA and 1,10-phenanthroline inhibited the keratinases, and the inhibition pattern indicated that they belong to metalloprotease. Keratinase from Bacillus sp. FHNM showed considerable residual activity in the presence of Co²⁺ (93percent), Fe³⁺ (99percent), and K⁺ (94percent). Bacillus sp. NFH5 keratinase retained 92percent, 92percent, 93percent of the original activity against Ba²⁺, Na⁺ and Fe³⁺ treatment. Bacillus sp. FHNM keratinase was remarkably stable after 60 min of detergents treatment with residual activity of 89percent, 96percent, 81percent, 73percent, 96percent, 88percent, 88percent and 98percent for Omo, Surf, Ariel, Sunlight, Prowash, Freshwave, Sky, and Evaklin, respectively. Maq impacted the enzyme stability negatively, with residual activity of 48percent after 60 min of incubation. Additionally, keratinase Bacillus sp. NFH5 retained 68percent, 78percent, 80percent, 84percent, 57percent, 80percent, 98percent, 106percent and 106percent of the original activity against Omo, Surf, Ariel, Sunlight, Maq, Prowash, Freshwave, Sky and Evaklin, respectively. Therefore, these results suggest that Bacillus spp. could be ideal candidates for sustainable production of active keratinases and valorization of the abundantly generated keratinous biomass. The stability displayed by keratinases from Bacillus sp. FHNM and Bacillus sp. NFH5 suggests their promising candidacy for detergent formulation. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Authors: Matches, Lupho
- Date: 2021-02
- Subjects: Proteolytic enzymes , Poultry -- Processing
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20451 , vital:45667
- Description: The poultry meat processing sector generates chicken feathers as by-products, and they are 90percent keratin in composition. Keratin is an insoluble and structural protein that shows recalcitrance to hydrolysis by classical proteolytic enzymes, including trypsin, pepsin, and papain. Keratinases are a group of proteolytic enzymes endowed with keratin degradation into peptides and amino acids. They are recently gaining traction for their multifaceted potential application in the green industrial space. Hence, keratinolytic bacteria previously isolated from dumpsite were identified using 16S rDNA sequencing. The optimal fermentation conditions were determined for enhanced extracellular keratinase production and chicken feather degradation. Also, the amino acid analysis of the chicken feather hydrolysates was carried out. The biochemical properties of the keratinases were also determined. Based on 16S rDNA sequencing and phylogenetic analysis, the isolates coded as SSN-02 and HSN-03 showed a high percentage of sequence homology with Bacillus spp.; hence, they were identified as Bacillus sp. NFH5 and Bacillus sp. FHNM, respectively. Bacillus sp. NFH5 showed optimal keratinase production of 1149.99 ± 80.99 U/mL after 96 h of incubation time, in optimized fermentation conditions that included pH (4.0), chicken feather (1.5percent, w/v), inoculum size (3percent, v/v) and temperature (30 oC). Similarly, Bacillus sp. FHNM demonstrated the maximum keratinase production of 480 ± 41.14 U/mL 144 h post cultivation, in optimized fermentation conditions with pH (7.0), chicken feather (2.0percent, w/v), inoculum size (3percent, v/v) and temperature (30 oC). For Bacillus sp. NFH5 chicken feather hydrolysate, the amino acids in relatively higher concentration (>1.0g/100g sample) include arginine (1.8), serine (1.16), aspartic acid (1.95), glutamic acid (2.47), proline (1.16) and glycine (1.45). Bacillus sp. FHNM feather hydrolysates, contained (g/100g of sample): arginine (1.9), serine (1.4), aspartic acid (2.5), glutamic acid (2.51), glycine (1.51), proline (1.13), leucine (1.030, histidine (1.25), and lysine (1.06) (g/100g of sample) in high concentration. The keratinases were optimally active at pH 8.0. Bacillus sp. FHNM showed an optimal temperature of 100 oC; while Bacillus sp. NFH5 keratinase displayed optimal activity at 90 oC. EDTA and 1,10-phenanthroline inhibited the keratinases, and the inhibition pattern indicated that they belong to metalloprotease. Keratinase from Bacillus sp. FHNM showed considerable residual activity in the presence of Co²⁺ (93percent), Fe³⁺ (99percent), and K⁺ (94percent). Bacillus sp. NFH5 keratinase retained 92percent, 92percent, 93percent of the original activity against Ba²⁺, Na⁺ and Fe³⁺ treatment. Bacillus sp. FHNM keratinase was remarkably stable after 60 min of detergents treatment with residual activity of 89percent, 96percent, 81percent, 73percent, 96percent, 88percent, 88percent and 98percent for Omo, Surf, Ariel, Sunlight, Prowash, Freshwave, Sky, and Evaklin, respectively. Maq impacted the enzyme stability negatively, with residual activity of 48percent after 60 min of incubation. Additionally, keratinase Bacillus sp. NFH5 retained 68percent, 78percent, 80percent, 84percent, 57percent, 80percent, 98percent, 106percent and 106percent of the original activity against Omo, Surf, Ariel, Sunlight, Maq, Prowash, Freshwave, Sky and Evaklin, respectively. Therefore, these results suggest that Bacillus spp. could be ideal candidates for sustainable production of active keratinases and valorization of the abundantly generated keratinous biomass. The stability displayed by keratinases from Bacillus sp. FHNM and Bacillus sp. NFH5 suggests their promising candidacy for detergent formulation. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
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Waste keratinous biomass valorization and characterization of keratinases produced by exiguobacteria species
- Authors: Dlume, Tutuka
- Date: 2021-02
- Subjects: Factory and trade waste -- Biodegradation , Bioremediation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20695 , vital:46438
- Description: Keratinous wastes are emanating in a million tons, as by-products, from various agro-industrial processing plants. Consequently, they create a serious solid waste problem in the environment due to poor handling. Microbial keratinases are proteolytic enzymes that effectively participate in keratin-rich biomass hydrolyses such as feathers, nail, hair, hooves, and horns. Therefore, proper management of these wastes via recycling into useful products is ecologically imperative. Biodegradation of keratin-rich biomass has been identified as an economical and environmentally friendly way of transforming these recalcitrant agro wastes into useful products, hence the motivation for this study. Feather degrading bacterial strains previously isolated from a municipal dumpsite and coded as SSB-02 and SSB-03 was identified through 16S rDNA sequencing and phylogenetic analysis. The fermentation conditions for keratinase production were optimized. The protein and amino acids constituents of the hydrolyzed chicken feather were analyzed. The biochemical properties of the keratinase produced were determined. Also, the effect of laundry detergents on the stability of the keratinase was studied. The isolates coded as SSB-02 and SSB-03 showed a high percentage of sequence homology with Exguobacterium spp., hence they were identified as Exiguobacterium sp. FBH5 and Exiguobacterium acetylicum FHBD, respectively. Exiguobacterium sp. FBH5 showed the highest extracellular keratinase production of 934.58 ± 27.27 U/mL at 72 h of incubation; in optimized fermentation conditions that included pH (5.0), temperature (30 oC), and chicken feather (0.5percent, w/v). Similarly, E. acetylicum FHBD displayed optimal keratinase production of 1023.64 ± 25.71 U/mL at 120 h of fermentation and improved fermentation conditions that involved pH (3.0), temperature (35 oC) and chicken feathers (0.5-1.5percent; w/v). The amino acid analysis showed that arginine, aspartic acid and glutamic acid were the most abundant amino acids cleaved from the degradation of chicken feathers by Exiguobacterium sp. FBH5 at a respective concentration of 1.16, 1.28 and 1.45 (g/100g sample). Additionally, hydrolysate that emanated from E. indicum FHBD degradation of feather showed high concentrations of arginine, serine, aspartic acid, glutamic acid, and glycine at the respective concentration (g/100g sample) of 1.2, 1.12, 1.34, 1.58 and 1.29. The keratinases were optimally active at pH and temperature of 8.0 and 50 oC, respectively. EDTA and PMSF did not highly repress keratinolytic proteases' activity, and this inhibitory pattern suggests that they may belong to a mixed protease family. Keratinase from E. acetylicum FHBD was highly stable in the presence of SDS, with 99percent residual activity and displayed variable stability in other chemical agents tested. A similar stability pattern was observed with keratinase from Exiguobacterium sp. FBH5, although the enzyme lost about 40percent of its original activity in the presence of SDS. Evaluation of metal ion stability indicated that E. acetylicum FHBD keratinase was remarkably stable in the presence of Fe3+, Mg2+, Cu2+, Zn2+, and Ba2+, with residual activity of 94percent, 88percent, 89percent, 90percent, and 97percent, respectively. Similarly, Exiguobacterium sp. FBH5 keratinase was considerably stable after treatment with Co2+, K+, and Zn2+ as it displayed a residual activity of 85percent, 84percent and 93percent, respectively. The study of the keratinases stability in laundry detergents showed that E. acetylicum FHBD keratinolytic proteases was activated in the presence of Omo, Surf, Sunlight, and Pro wash after 60 min of pre-incubation compared to 30 min, with residual activity of 94 ± 2.94percent, 91 ± 2.53percent, 95 ± 2.89percent and 87 ± 2.89percent respectively. Likewise, Exiguobacterium sp. FBH5 keratinase activity was promoted after 60 min of incubation compared to 30 min, with a residual enzyme activity of 79percent, 84percent, 101percent, 103percent and 105percent and 106percent for Ariel, Surf, Prowash, Freewave, Sky and Evaklin, respectively. Therefore Exiguobacterium spp., demonstrated excellent keratinolytic potentials that could be exploited for sustainable development of bio-innovative products. The study keratinases' properties suggest their industrial and biotechnological application potentials, especially as bio-additive in the formulation of laundry detergents. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Authors: Dlume, Tutuka
- Date: 2021-02
- Subjects: Factory and trade waste -- Biodegradation , Bioremediation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20695 , vital:46438
- Description: Keratinous wastes are emanating in a million tons, as by-products, from various agro-industrial processing plants. Consequently, they create a serious solid waste problem in the environment due to poor handling. Microbial keratinases are proteolytic enzymes that effectively participate in keratin-rich biomass hydrolyses such as feathers, nail, hair, hooves, and horns. Therefore, proper management of these wastes via recycling into useful products is ecologically imperative. Biodegradation of keratin-rich biomass has been identified as an economical and environmentally friendly way of transforming these recalcitrant agro wastes into useful products, hence the motivation for this study. Feather degrading bacterial strains previously isolated from a municipal dumpsite and coded as SSB-02 and SSB-03 was identified through 16S rDNA sequencing and phylogenetic analysis. The fermentation conditions for keratinase production were optimized. The protein and amino acids constituents of the hydrolyzed chicken feather were analyzed. The biochemical properties of the keratinase produced were determined. Also, the effect of laundry detergents on the stability of the keratinase was studied. The isolates coded as SSB-02 and SSB-03 showed a high percentage of sequence homology with Exguobacterium spp., hence they were identified as Exiguobacterium sp. FBH5 and Exiguobacterium acetylicum FHBD, respectively. Exiguobacterium sp. FBH5 showed the highest extracellular keratinase production of 934.58 ± 27.27 U/mL at 72 h of incubation; in optimized fermentation conditions that included pH (5.0), temperature (30 oC), and chicken feather (0.5percent, w/v). Similarly, E. acetylicum FHBD displayed optimal keratinase production of 1023.64 ± 25.71 U/mL at 120 h of fermentation and improved fermentation conditions that involved pH (3.0), temperature (35 oC) and chicken feathers (0.5-1.5percent; w/v). The amino acid analysis showed that arginine, aspartic acid and glutamic acid were the most abundant amino acids cleaved from the degradation of chicken feathers by Exiguobacterium sp. FBH5 at a respective concentration of 1.16, 1.28 and 1.45 (g/100g sample). Additionally, hydrolysate that emanated from E. indicum FHBD degradation of feather showed high concentrations of arginine, serine, aspartic acid, glutamic acid, and glycine at the respective concentration (g/100g sample) of 1.2, 1.12, 1.34, 1.58 and 1.29. The keratinases were optimally active at pH and temperature of 8.0 and 50 oC, respectively. EDTA and PMSF did not highly repress keratinolytic proteases' activity, and this inhibitory pattern suggests that they may belong to a mixed protease family. Keratinase from E. acetylicum FHBD was highly stable in the presence of SDS, with 99percent residual activity and displayed variable stability in other chemical agents tested. A similar stability pattern was observed with keratinase from Exiguobacterium sp. FBH5, although the enzyme lost about 40percent of its original activity in the presence of SDS. Evaluation of metal ion stability indicated that E. acetylicum FHBD keratinase was remarkably stable in the presence of Fe3+, Mg2+, Cu2+, Zn2+, and Ba2+, with residual activity of 94percent, 88percent, 89percent, 90percent, and 97percent, respectively. Similarly, Exiguobacterium sp. FBH5 keratinase was considerably stable after treatment with Co2+, K+, and Zn2+ as it displayed a residual activity of 85percent, 84percent and 93percent, respectively. The study of the keratinases stability in laundry detergents showed that E. acetylicum FHBD keratinolytic proteases was activated in the presence of Omo, Surf, Sunlight, and Pro wash after 60 min of pre-incubation compared to 30 min, with residual activity of 94 ± 2.94percent, 91 ± 2.53percent, 95 ± 2.89percent and 87 ± 2.89percent respectively. Likewise, Exiguobacterium sp. FBH5 keratinase activity was promoted after 60 min of incubation compared to 30 min, with a residual enzyme activity of 79percent, 84percent, 101percent, 103percent and 105percent and 106percent for Ariel, Surf, Prowash, Freewave, Sky and Evaklin, respectively. Therefore Exiguobacterium spp., demonstrated excellent keratinolytic potentials that could be exploited for sustainable development of bio-innovative products. The study keratinases' properties suggest their industrial and biotechnological application potentials, especially as bio-additive in the formulation of laundry detergents. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
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