Assessment of the flocculating efficiency of bioflocculant produced by bacillus sp. Aemreg4 isolated from Tyhume river, Eastern Cape, South Africa
- Authors: Ntsangani, Nozipho
- Date: 2016
- Subjects: Flocculants
- Language: English
- Type: Thesis , Masters , MSc (Biochemistry)
- Identifier: vital:11357 , http://hdl.handle.net/10353/d1021324
- Description: Bioflocculants are flocculating substances produced by microorganisms during growth and have recently received considerable attention from researchers; due to their biodegradability, non-toxicity and lack of secondary pollution from degradation intermediates. This study evaluated the efficiency of bioflocculant produced by Bacillus sp. AEMREG4 isolated from Tyhume River. The bacterial identification was through 16S rDNA sequencing; nucleotide sequences were deposited in GenBank as Bacillus sp. AEMREG4 with an Accession number KP406729. The optimum culture conditions for bioflocculant production were an inoculum size of 4% (v/v) and starch as well as yeast extract as sole carbon and nitrogen sources respectively. The addition of CaCl2 enhanced the flocculating activity, at a wide range of pH 4-10 and the highest flocculating activity was reached at an initial pH 8 (80%). A bioflocculant yield of 0.78 g was recovered from 1 L of culture broth. The optimum flocculating activity of 78% was reached at the lowest bioflocculant dosage of 0.1 mg/ml and the presence of divalent cations (Ca2+, Mn2+ and Mg2+) as well as a trivalent cation (Al3+) enhanced flocculating activity. The purified bioflocculant retained more than 70% flocculating activity when subjected to heating at 100 °C for 1 h and maximum flocculating activity of 83% was achieved at both acidic and basic pH values of 3 and 10 respectively. Chemical analysis showed that the bioflocculant is predominantly polysaccharide. The Fourier transform infrared (FTIR) spectrum revealed the presence of carboxyl, hydroxyl and methoxyl groups as the functional moieties and the scanning electron microscopy (SEM) imaging of the purified bioflocculant showed its morphological structure as rod-shaped which contributes to its high flocculating efficiency. The high flocculation activity displayed by this bioflocculant indicates its potential suitability for industrial application.Keywords: Bioflocculant, Bacillus sp. AEMREG4, flocculating activity.
- Full Text:
- Date Issued: 2016
Assessment of bioflocculant production by two marine bacteria isolated from the bottom sediment of marine Algoa Bay
- Authors: Ntozonke, Ncedo
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11298 , http://hdl.handle.net/10353/d1021290
- Description: Bioflocculants are polymers, mostly, of microbial origin which floc out suspended particles from liquid medium. The ability of these biopolymers to remove suspended particles from solutions is termed bioflocculation, and the efficiency of flocculation activities depends on the characteristics of the flocculants. In comparison with conventionally used flocculants, bioflocculants have the advantage of being safe (no toxic effects known), biodegradable and harmlessness to the environment. The study assessed production of bioflocculant by two marine bacteria from the bottom sediment of marine environment. The 16S rDNA was used for identification, and the two bacteria species were identified as Enterococcus hirae and Bacillus thuringiensis. Factors affecting the production and activity of the bioflocculants produced by these two organisms were studied. The bacteria optimally produced bioflocculant with fructose (91.7%) and urea (91%) as sole carbon and nitrogen sources respectively. Mg2+ (87%) and Ca2+ (86%), likewise, served as best cation sources on the production of the bioflocculant at pH 5(93%). Additionally, the flocculating activity of the bioflocculant increased with the addition of Mg2+ (81%) and Na+ (81%), and the highest flocculating activity was at pH 5 of the kaolin clay. The Fourier transform infrared spectroscopy (FTIR) shows that the bioflocculant is a glycoprotein. The second bacterium (Bacillus thuringiensis) produced bioflocculant optimally when the media had mixed nitrogen sources (Urea, ammonium chloride and tryptone (67%)) and glucose (85.65%) as a sole carbon source, also Ca2+ (74.6%) was the best cation that induced the production of bioflocculant. After purification, the bioflocculant flocculated optimally in alkaline pH 12 (81%) in the presence of Mn2+ (73%) and Ca2+ (72.8%). Chemical analysis of the bioflocculant revealed it to be a polysaccharide. Both bioflocculants flocculate efficiently and can be used to replace synthetic flocculants in water treatment, wastewater, in downstream processing, and processing of food and chemicals and other industrial uses of flocculants. Challenges though (i) are to develop conditions for large scale production of the bioflocculant, (ii) to do further characterization of the both bioflocculants (iii) to assess the bioflocculants for treatments of water/wastewater, and to apply it in various industrial processes.
- Full Text:
- Date Issued: 2015
Characterization of some virulence and antibiotic resistance genes of Staphylococcus aureus isolated from cases of Bovine Mastitis in Nkonkobe Municipality, Eastern Cape Province, RSA
- Authors: Pekana, Abongile
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11293 , http://hdl.handle.net/10353/d1021133
- Description: Staphylococcus aureus is one of the predominant causative agents of mastitis disease in dairy herds. Mastitis disease has a negative impact in the economic losses in the dairy sector across the globe. The aim of this study is to detect some of the virulence genes in the S. aureus isolated from 400 milk samples of subclinical and clinical mastitis dairy cows in Fort Hare dairy farm and Middle Drift dairy farm in Alice in the Eastern Cape province of South Africa. In addition antibiotic resistance pattern and antibiotic resistance genes were investigated. Gram-staining, oxidase test, catalase test and API Staph kit were preliminary biochemical tests used for the identification of S. aureus isolates. The MALDI-TOF-MS was also used for further identification. Polymerase chain reaction was performed of genes encoding antibiotic resistance as well as clumping (clfA), coagulase (coa) gene, toxic shock syndrome (tsst), exfoliative toxin A and B (eta and etb), and the gene segment encoding the immunoglobulin G binding region and X region of protein gene spa. A total of 20 (5%) S. aureus strains obtained from 400 milk samples from the two farms were subjected to 16 antibiotics for antibiotic susceptibility testing. In Middle Drift dairy farm 11 (5.5%) isolates were obtained from 200 samples and 9 (4.5%) isolates were obtained in Fort Hare dairy farm from 200 samples. A large percent of the isolates were resistant to penicillin G (60%), followed by trimethoprim (60%) and tetracycline (60%), trimethoprim-sulfamethaxazole (55%), telithroprim (55%) and doxycycline (45%). Most of the isolates were sensitive to several (50-85%) antibiotics. Of the twenty isolates tested 12 samples contained the penicillin antibiotic resistance gene (blaZ gene), 8 samples contained at least one aminoglycoside-modifying enzyme gene (AME gene); the (aac(6’)/aph(2’’) gene and no amplification occurred for aph(3’)-IIIa and ant(4’)-Ia) genes. In the case of the tetracycline antibiotic resistance gene (tetK and tetM), 2 samples contained tetM and a single sample contained tetK gene. No amplification was observed for the erythromycin antibiotic resistance genes (ermA, ermB, ermC, Mef and msrA). All the samples tested were negative for the expression of toxic syndrome gene (tsst), etb, and Immunoglobulin G binding region. However, amplification of the clumping factor was observed in 7 (35%) isolates of S. aureus, exfoliative toxin (eta) expressed 4(20%) isolates; coagulase gene (coa) yielded six DNA bands of six differences sizes from 16 (80%) isolates. A total of four different bands size were expressed for the spa X region from 12 (60%) isolates. The data obtained in this study suggests that poor hygienic practices and inadequate management practices are responsible for the increase in Staphylococcus aureus isolation. The high resistance of S. aureus to antibiotics and the distribution of virulence genes contribute in bovine mastitis in these farms may cause health problems in the community consuming raw milk purchased from these farms.
- Full Text:
- Date Issued: 2015
Isolation and characterisation of lignocellulose degrading bacteria from Tyume River in the Eastern Cape Province, South Africa
- Authors: Tembisa, Papiyana Ayavuya
- Date: 2015
- Subjects: Lignocellulose -- Biodegradation -- South Africa -- Eastern Cape , Bacillus (Bacteria) -- South Africa -- Eastern Cape , Waterborne infection -- South Africa -- Eastern Cape , Bacteriophages -- South Africa -- Eastern Cape , Sediments (Geology) -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11299 , http://hdl.handle.net/10353/d1021293 , Lignocellulose -- Biodegradation -- South Africa -- Eastern Cape , Bacillus (Bacteria) -- South Africa -- Eastern Cape , Waterborne infection -- South Africa -- Eastern Cape , Bacteriophages -- South Africa -- Eastern Cape , Sediments (Geology) -- South Africa -- Eastern Cape
- Description: This study focuses on the isolation and characterization of bacteria from lignocellulosic biomass obtained from the sediments of the Tyume River in Alice, Eastern Cape and to determine those bacterial isolates with good potential for modification and decomposition of lignocellulosic biomass for industrial application. Several bacterial isolates were recovered and screened for ability to degrade various lignocellulosic materials. Nine of the isolates were positive for lignocellulolytic activity. Four isolates were cellulase positive and six were xylanase positive. Moreover, one isolate (SB1) was positive for both xylanase and cellulase activities and showed the best hydrolysis zone on solid media. This isolate was then chosen as the best and identified molecularly. The 16S rDNA sequence analysis indicated that SB1 was a Bacillus cereus species. Factors affecting the cellulose and xylanase enzyme production by the organisms were studied. The organisms produced the enzymes maximally at earlier hours of incubation (12-30 hr) and optimally at acidic pH (3-5) and at moderate temperatures (35-45ºC). SB1 appears to hold promise in the decomposition of lignocellulosic wastes.
- Full Text:
- Date Issued: 2015
Isolation and molecular characterization of Bacillus cereus from cow’s raw milk
- Authors: Lukanji, Zinathi , Ndip, R N
- Date: 2015
- Subjects: Milk contamination -- South Africa -- Eastern Cape , Bacillus (Bacteria) -- South Africa -- Eastern Cape , Foodborne diseases -- Molecular diagnosis -- South Africa -- Eastern Cape , Dairy products -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11296 , http://hdl.handle.net/10353/d1021284 , Milk contamination -- South Africa -- Eastern Cape , Bacillus (Bacteria) -- South Africa -- Eastern Cape , Foodborne diseases -- Molecular diagnosis -- South Africa -- Eastern Cape , Dairy products -- South Africa -- Eastern Cape
- Description: Bacillus cereus is a group of ubiquitous facultative anaerobic spore forming Gram-positive rods commonly found in soil. It has been detected and implicated in several contaminated food products and raw milk in dairy farms and it causes foodborne gastroenteritis by producing several toxins. This study is aimed at characterizing virulence determinants of B. cereus from cow‟s raw milk. A total of 400 raw milk samples were collected in Fort Hare Dairy Trust and Middledrift Dairy Farm; and cultured on Polymyxin pyruvate Egg-Yolk Mannitol Bromothymol Agar (PEMBA) for 48 hours at 37°C. DNA was isolated from the isolates and 16S rDNA was amplified and sent to Central Analytical Laboratory for sequencing. The gyrB gene of B. cereus was also used to confirm the identity of the isolates. Antibiotic susceptibility profiles of the isolates together with virulence genes were investigated. Multilocus Sequence typing was used to investigate the genetic relatedness of some selected isolates. Furthermore, spores of the isolates were produced, harvested and their concentrations determined. All (100%) of the isolates were identified as having a 96-99% similarity to B. cereus, B. thuringiensis and B. anthracis using sequencing; while gyrB gene was observed in all (100%) of the isolates. Three virulence genes nheA, nheB, nheC encoding for non haemolysin enterotoxin were amplified in all (100%) the isolates. All (100%) of the isolates were susceptible to doxycycline, gentamycin, tetracycline, ciprofloxacin, chloramphenicol and streptomycin. Resistance to rifampicin and penicillin G was predominant with equal rate of 100%, while susceptibility to erythromycin, clindamycin and doxycycline ranged from 60% to 100%. The selected isolates were related and are descendants of the same ancestor. All (100%) the isolates produced spores. The B. cereus isolates contain virulence genes, has multiple antibiotic drug resistance and produce spores, which poses a health risk to the public and cannot be used as probiotics.
- Full Text:
- Date Issued: 2015
Prevalence and antibiogram of some swine associated Shiga toxin producing Escherichia coli Serogroups and Salmonella species in Nkonkobe Municipality, Eastern Cape Province, South Africa
- Authors: Iwu, Chinwe Juliana
- Date: 2015
- Subjects: Escherichia coli -- South Africa -- Eastern Cape , Salmonella infections -- South Africa -- Eastern Cape , Water -- Pollution -- Environmental aspects -- South Africa -- Eastern Cape , Escherichia coli infections -- South Africa -- Eastern Cape , Water quality management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11294 , http://hdl.handle.net/10353/d1021273 , Escherichia coli -- South Africa -- Eastern Cape , Salmonella infections -- South Africa -- Eastern Cape , Water -- Pollution -- Environmental aspects -- South Africa -- Eastern Cape , Escherichia coli infections -- South Africa -- Eastern Cape , Water quality management -- South Africa -- Eastern Cape
- Description: Gastrointestinal illnesses have continually become a global public health issue. Exposure to zoonotic food borne pathogens such as Salmonella and diarrhoegenic E. coli either by direct or indirect contact through the consumption of food producing animals is likely an important mode of infection to humans. More so, the use of antibiotics in farm animals similar to those used in humans can select for resistance in bacteria frequently harboured by them. These resistant strains can be passed on to humans through contaminated meat products and water leading to resistant infections with consequences such as prolonged illnesses, treatment failures, and increased morbidity and mortality. In animals, these can lead to reduced productivity. Monitoring the level of resistance among bacteria from animal isolates will help in generating data that could be used to create awareness of their presence in the environment and aid in preventing a potential epidemic in the community. In this study, we investigated the prevalence and antimicrobial resistance profile of Escherichia coli serogroups and Salmonella species in faecal samples collected from pigs in Nkonkobe Municipality in the Eastern Cape Province, South Africa between April – July, 2014. A total of 310 presumptive Shiga toxin producing Escherichia coli (STEC) were confirmed as E. coli spp using polymerase chain reaction (PCR) technique by amplification of the uidA gene, out of which 179 (58%) were confirmed positive. Approximately, serogrougs O157:H7, O145 and O26 made up 24% (n=43), 8% (n=14) and 20% (n=35) of the E. coli population respectively. Only E. coli O26 was positive for stx2 gene in 31% of the isolates harbouring the gene, while the other serogroups were non-pathogenic. Susceptibility of the isolates to 18 antibiotics was carried out in vitro by the standardized agar disc-diffusion method. All the isolates were susceptible to imipenem. Similarly, a relatively high susceptibility was observed in norfloxacin (83-100%), ciprofloxacin (63-100%), gentamycin (77-100%), and chloramphenicol (77-100%). However, all the isolates were resistant to tetracycline and its long acting counterpart oxytetracycline. Resistances observed against other antimicrobials are as follows: ampicillin (84-91%), streptomycin (14-100%), erythromycin (91-100%), ceftazidime (35%). Multiple antimicrobial resistance patterns and indices ranged from 3 to 12 and 0.2 to 0.7 to respectively. Genes encoding resistances to ampicillin (ampC), streptomycin (strA) and tetracycline (tetA) were frequently detected in 50-100%, 22-29% and 40-86% of the resistant isolates respectively. In the other arm of the dissertation, two hundred and fifty eight presumptive isolates of Salmonella were recovered from the faecal samples of pigs. Specific primers targeting serogroups A, B, C1, C2, and D were used to delineate the isolates into different serogroups using PCR. Only serogroup A (n=48) was detected. These isolates were examined for antimicrobial susceptibility by disc diffusion method using 18 antibiotics. The results showed that a large proportion of the isolates were resistant to tetracycline (100%), oxytetracycline (100%), ampicillin (75%), sulphamethoxazole/trimethoprim (75%) and streptomycin (75%). Majority of the isolates exhibited multidrug resistances with the predominant multiple antibiotic resistance (MAR) phenotype being against eleven antibiotics. A high multiple antibiotic resistance (MAR) index in a range of 0.3- 0.6 was observed. The incidence of genes encoding resistance against tetracycline (tetA), streptomycin (stra), and ampicillin (ampC) were 54%, 44% and 61% respectively. These findings reveal that pigs within the Nkonkobe Municipality in the Eastern Cape Province could harbour Shiga toxins and multidrug resistant serogroups of E. coli as well as resistant Salmonella which could be transmitted to humans through the food chain. To ensure public health safety, continuous monitoring and sufficient sanitation in swine industries must be ensured.
- Full Text:
- Date Issued: 2015
Antibiogram profiling of Escherichia coli pathotypes isolated from Kat River and Fort Beaufort abstraction water
- Authors: Nontongana, Nolonwabo
- Date: 2014
- Subjects: Escherichia coli infections -- South Africa -- Eastern Cape , Water -- Pollution -- Environmental aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11289 , http://hdl.handle.net/10353/d1019820 , Escherichia coli infections -- South Africa -- Eastern Cape , Water -- Pollution -- Environmental aspects -- South Africa -- Eastern Cape
- Description: Escherichia coli (E. coli) is a widespread species that includes a broad variety of strains, ranging from highly pathogenic strains causing worldwide outbreaks of severe disease to virulent isolates which are part of the normal intestinal flora or which are well characterized and safe laboratory strains. The pathogenicity of a given E. coli strain is mainly determined by specific virulence factors which include adhesins, invasins, toxins and capsule. The aim of this study was to evaluate the prevalence and antibiogram profiles of E. coli pathotypes previously isolated from Kat River and Fort Beaufort abstraction water. A total of 171 E. coli isolates showed at least one pathogenic determinant among the isolated 278 E. coli. The other 107 isolates were negative for the tested virulence genes. All 278 presumptive isolates tested positive for the UidA gene, and were therefore classified as non-categorized pathogenic E. coli. The 171 pathogenic isolates had at least one characteristic gene of pathogenic E. coli and were identified and classified as enteropathogenic E. coli (6%), enterotoxigenicE. coli (131), uropathogenic E. coli (6), neonatal meningitis E. coli (14), diffusely adherent E. coli (1) and enterohaemrrhagic E. coli (1). Interestingly, no virulence genes were detected for the enteroinvasive E. coli and the enteroaggregative E. coli. The antibiotic resistance profiles for all isolates that were identified as E. coli showed 100% resistance to penicillin G, 98% resistance to ampicillin, 38% resistance to trimethoprim-sulphamethoxazole and 8% resistance to streptomycin. Multiple antibacterial resistance (MAR) was also observed, where 44% of the isolates were resistant to three antibiotics and 8% resistant to four antibiotics. The results of this study showed the Kat River and Fort Beaufort abstraction water are reservoirs of pathogenic strains of E. coli which harbour antibiotic resistance determinants that can cause serious health risks to the people in the surrounding communities.
- Full Text:
- Date Issued: 2014
Assessment of the prevalence of faecal coliforms and Escherichia coli o157:h7 in the final effluents of two wastewater treatment plants in Amahlathi Local Municipality of Eastern Cape Province, South Africa
- Authors: Ajibade, Adefisoye Martins
- Date: 2014
- Subjects: Sewage disposal plants , Escherichia coli -- South Africa -- Eastern Cape , Escherichia coli O157:H7 , Escherichia coli , Effluent quality -- Testing , Whole effluent toxicity testing , Water -- Purification
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11283 , http://hdl.handle.net/10353/d1016166 , Sewage disposal plants , Escherichia coli -- South Africa -- Eastern Cape , Escherichia coli O157:H7 , Escherichia coli , Effluent quality -- Testing , Whole effluent toxicity testing , Water -- Purification
- Description: The production of final effluents that meet discharged requirements and guidelines remain a major challenge particularly in the developing world with the resultant problem of surface water pollution. This study assessed the physicochemical and microbiological qualities of two wastewater treatment works in the Eastern Cape Province of South Africa in terms of the prevalence of faecal coliforms and Escherichia coli O157:H7 over a five month period. All physicochemical and microbiological analyses were carried out using standard methods. Data were collected in triplicates and analysed statistically using IBM SPSS version 20.0. The ranges of some of the physicochemical parameters that complied with set guidelines include pH (6.7 – 7.6), TDS (107 – 171 mg/L), EC (168 – 266 μS/cm), Temperature (15 – 24oC), NO3- (0 – 8.2 mg/L), NO2- (0.14 – 0.71 mg/L) and PO4 (1.05 – 4.50 mg/L). Others including Turbidity (2.64 – 58.00 NTU), Free Cl (0.13 – 0.65 mg/L), DO (2.20 – 8.48 mg/L), BOD (0.13 – 6.85 mg/L) and COD (40 – 482 mg/L) did not comply with set guidelines. The microbiological parameters ranged 0 – 2.7 × 104 CFU/100 ml for FC and 0 – 9.3 × 103 for EHEC CFU/100 ml, an indication of non-compliance with set guidelines. Preliminary identification of 40 randomly selected presumptive enterohemorrhagic E. coli isolates by Gram’s staining and oxidase test shows 100% (all 40 selected isolates) to be Gram positive while 90% (36 randomly selected isolates) were oxidase negative. Statistical correlation between the physicochemical and the microbiological parameters were generally weak except in the case of free chlorine and DO where they showed inverse correlation with the microbiological parameters. The recovery of EHEC showed the inefficiency of the treatment processes to effectively inactivate the bacteria, and possibly other pathogenic bacteria that may be present in the treated wastewater. The assessment suggested the need for proper monitoring and a review of the treatment procedures used at these treatment works.
- Full Text:
- Date Issued: 2014
Enterococcus pathotypes as reservoirs of antibiotic resistance determinants in the Kat River and Fort Beaufort abstraction waters
- Authors: Ntloko, Phindiwe
- Date: 2014
- Subjects: Enterococcus , Drug resistance
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11290 , http://hdl.handle.net/10353/d1019821 , Enterococcus , Drug resistance
- Description: In this study, 400 presumptive Enterococcus isolates previously recovered from Kat River and Fort Beaufort Abstraction water dam were subjected to molecular confirmation and pathotyping. Two hundred and seventy-four (68%) of these isolates were confirmed to be enterococci species. Confirmations studies were polymerase chain reaction (PCR) based, using enterococci specific primers targeting the tuf gene. The confirmed enterococci isolates were further differentiated into their pathotypes, the targets of which were: E. faecalis, E. avium, E. hirae, E. casseliflavarus and E. gallinarum using well documented species specific primer sequences. E. faecalis accounted for 20% of the isolates, followed by E. avium (16%), E. hirae (13%), E. casseliflavarus (5%) and E. gallinarum (3%). Furthermore, all the confirmed isolates were analysed for antibiotic susceptibilities using a panel of nine different antibiotics, namely vancomycin, linezolid, ciprofloxacin, ampicillin, gentamicin, chloramphenicol, tetracycline, erythromycin, penicillin, and those that were resistant were assayed for the presence of relevant antibiotic resistance genes. All the 274 isolates were found to harbour vanA resistance gene confirming their phenotypic resistance to the vancomycin. Similarly, 60% (109/180) of the isolates showed phenotypic resistance to erythromycin which was further confirmed by the presence of ermA genes in these isolates. The presence of antibiotic resistant bacteria in surface waters poses a risk to public health.
- Full Text:
- Date Issued: 2014
Evaluation of some wastewater treatment facilities in Chris Hani and Amathole district municipalities as potential sources of Escherichia coli in the environment
- Authors: Mazwi, Sinazo Nomathamsanqa
- Date: 2014
- Subjects: Escherichia coli -- South Africa -- Eastern Cape , Water -- Purification
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11285 , http://hdl.handle.net/10353/d1019804 , Escherichia coli -- South Africa -- Eastern Cape , Water -- Purification
- Description: Access to clean and safe water is essential for the survival of human beings. Pollution of freshwater sources constitutes a major problem hindering access to safe water for drinking and other domestic uses. Wastewater effluent discharges often impact the microbiological qualities of surface waters with its attendant health and environmental problems. This study evaluated the microbiological qualities of the discharged effluents of four selected wastewater treatment plants in Amathole and Chris Hani District Municipalities of the Eastern Cape Province over a twelve-month sampling period. Microbiological analysis (faecal coliform, Escherichia coli and Escherichia coli O157:H7) was done using standard methods and polymerase chain reaction method was used to confirm identities ofbacterial isolates. Presumptive bacteria counts ranged as follows: faecal coliforms 0 to 1.6 × 103 CFU/100 ml, E. coli 0 to 1.4 × 103 CFU/100 ml and E. coli O157:H7 0 to 9.6 × 102 CFU/100 ml. Forty eight percent (305/626) of the presumptive E. coli isolates were confirmed using species-specific uidA gene which code for β-glucuronidase enzyme in E. coli. Antibiotic susceptibility profile of the isolate using a panel of 10 antibiotics shows 100% (150/150) resistance to antibiotics rifampicin and penicillin G while 49.3% (74/150) of the isolates and 46.7% (70/150) were susceptible to streptomycin and cefotaxime respectively. Multiple antibiotic resistance phenotypes (MARP) of the isolates showed resistance to two or more test antibiotics while the calculated multiple antibiotic resistance index (MARI) for the tested isolated is 0.49. The detection of potentially pathogenic E. coli in the final effluents suggestspotential danger to the receiving water bodies where the effluents are discharge. The high MARI valued obtained in this study indicates that the isolates are form environment where the tested antibiotics are being used and may further lead to the spread of multiple antibiotics resistance among other pathogens that may be present in the same environment.
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- Date Issued: 2014
Evaluation of the final effluents of some wastewater treatment plants in Amathole and Chris Hani District Municipality of the Eastern Cape Province as sources of vibrio pathogens in the aquatic environment
- Authors: Nongogo, Vuyokazi
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11287 , http://hdl.handle.net/10353/d1019813
- Description: Certain areas in the world still depend on the receiving water bodies as sources of domestic water and for recreational purposes. The discharge of poor quality effluents from wastewater treatment plants can impact negatively on these water bodies, as they can act as vehicles for pathogens to the environment, posing a threat to humans if such water is used without precaution. Vibrio species are amongst those pathogens that can survive wastewater treatment processes, ending up in the environment, hence the aim of this study was to evaluate the final effluents of some wastewater treatment plants as sources of vibrio pathogens. Five wastewater treatment plants (WWTP) located in Amathole and Chris Hani District Municipalities in the Eastern Cape were used in this study. Samples were collected monthly from September 2012 – August 2013 and analysed using the standard membrane filtration technique. Yellow and green colonies on TCBS agar were enumerated as presumptive Vibrio species and expressed as CFU/100ml for each plant. Colonies were later picked based on their phenotypic characteristics, sub-cultured on fresh TCBS agar to ascertain purity. These presumptive isolates were then subjected to Gram staining and Oxidase test. Gram negative and Oxidase positive isolates were selected for further confirmation using Polymerised Chain Reaction (PCR). PCR was also employed for characterisation of Vibrio into three species viz V. parahaemolyticus, V. fluvialis and V. vulnificus. Antibiogram profile of the characterised species was then determined together with the presence of relevant antibiotic resistance genes Vibrio densities for the twelve month period ranged between 0 - 1.48×104 CFU/100ml with two of the plants located in East bank and Queenstown characterized by extremely high counts and one plant( Reeston) with very low counts.Three hundred presumptive Vibrio isolates were screened for identity confirmation. Of these, the dominating species found was V. fluvialis (28.6%) followed by V. vulnificus (28%) and the least was found to be V. parahaemolyticus (11.6%). The remaining unidentified 31.6% were suspected to belong to other Vibrio species not covered within the scope of this study. All the confirmed isolates i.e., V. parahaemolyticus, V. vulnificus and V. fluvialis were susceptible to imipenem, gentamicin and meropenem and resistant to only tetracycline. Between 60-100% of the V. parahaemolyticus isolates, 7.1% to 100 % V. vulnificus isolates and 2.5 to 100 % V. fluvialis showed resistances to polymixin B, sulfamethazole, erythromycin, penicillin G, chloramphenicol, trimethroprim and trimethroprim & sulfamethazole. Antibiotic Resistance Genes that were assessed included dfRA, SXT, floR and Sul2 varying in proportion with each species showing diversity in the Vibrio community. The dfR A gene was detected in all the V. parahaemolyticus isolates while floR gene was not detected in any of the isolates belonging to the three species. The distribution of sul2 gene cut across the species being 1% (1) in V. fluvialis, 3% (1) in V. parahaemolyticus and 4% (3) in V. vulnificus. The SXT gene was only determined in V. parahaemolyticus. It is clear that the final effluents of the selected plants are reservoirs for Vibrio pathogens as well as antibiotic resistance genes in the environment. The isolation of Vibrio from WWTP shows that this pathogen is in circulation in some pockets of the population. Therefore, wastewater treatment plants need to be properly monitored to ensure that they comply with set guidelines.
- Full Text:
- Date Issued: 2014
Molecular study of mycobacterium tuberculosis complex (MTBC) DNA from Port Elizabeth
- Authors: Londiwe, Bhembe Nolwazi
- Date: 2014
- Subjects: Mycobacterium tuberculosis
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11281 , http://hdl.handle.net/10353/d1016163 , Mycobacterium tuberculosis
- Description: Mycobacterium tuberculosis complex (MTBC) is a causative agent of tuberculosis (TB) in humans and animals. The burden of tuberculosis in South Africa is worsened by the concurrent epidemic of HIV. The dynamic of TB epidemics has been investigated and yet little data has been given about the Eastern Cape, particularly Port Elizabeth. The study aimed to investigate the prevalence of drug resistant MTBC and to determine the mutations causing resistance in Port Elizabeth. One hundred and ninety (190) DNA samples isolated from sputum specimen in humans suspected of having TB were amplified using the Seeplex® MTB Nested ACE detection assay. To differentiate Mycobacterium tuberculosis complex (MTBC) members for surveillance purposes a multiplex polymerase chain reaction (PCR) method was done based on genomic regions of differences such as RD1, RD1mic, RD2seal, RD4, RD9 and RD12. Target genes known to confer resistance to first and second-line drugs were amplified and the amplicons sequenced using Big Dye Terminator DNA sequencing kit v3.1 (Applied Biosystems, UK). The patient’s demographic profiles were obtained from the National Health Laboratory Service (NHLS). All hundred and ninety DNA samples tested positive for MTBC using the Seeplex® MTB Nested ACE assay. Results show a high prevalence of extensive drug resistant TB in Port Elizabeth, Eastern Cape Province. One hundred and eighty four (184) DNA isolates were used in the identification of different MTBC species. We ended up working with 184 DNA isolates because we ran out of DNA, and we could not go back to isolate DNA from the affected individuals due to the fact that some patients died, while some have been released to go to their homes. From the 184 DNA isolates 45 (24.5%) isolates were identified to be M. tuberculosis, 94 isolates (51.1%) to be M. bovis BCG and 3 isolates (1.6%) to be M. cannetti. Sequencing results show the position of mutation in each DNA isolate; however in the study we got resistance to MDR to be 100% and 42% pre-XDR while 58% was XDR. These results raise an alarm for the prevalence MDR in MTBC from Port Elizabeth. This is a serious health concern which calls for a need to strategise on the identification of extensive drug resistant TB patients from multi-drug resistant TB patients and ensure monitoring of their treatment.
- Full Text:
- Date Issued: 2014
Prevalence and pathogenicity of vibrios in treated final effluents of selected wastewater treatment plants in the Amathole District Municipality of Eastern Cape Province of South Africa
- Authors: Badela, Andiswa Unathi
- Date: 2014
- Subjects: Sewage disposal plants -- South Africa -- Eastern Cape , Whole effluent toxicity testing -- South Africa -- Eastern Cape , Escherichia coli -- South Africa -- Eastern Cape , Bacterial diseases -- Pathogenesis
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11284 , http://hdl.handle.net/10353/d1019774 , Sewage disposal plants -- South Africa -- Eastern Cape , Whole effluent toxicity testing -- South Africa -- Eastern Cape , Escherichia coli -- South Africa -- Eastern Cape , Bacterial diseases -- Pathogenesis
- Description: Waterborne diarrhoeal infections continue to be a major health setback in developing countries, especially in rural areas which lack adequate supply of portable water and sanitation facilities. Globally, waterborne diarrhoeal infections occur with an estimated mortality rate of 10–25 million deaths per year, 95% of which are children under the age of 5 years. The Vibrio species is one of the major groups of enteric pathogens that are responsible for diarrhoeal infections. Many strains of these bacterial species continue to cause epidemics of diarrhoea throughout the world. In this study, the prevalence of Vibrio pathogens in wastewater final effluents was assessed. Wastewater final effluent and discharge point samples were collected monthly between September 2012 and August 2013. All samples were collected aseptically using sterile 1 L Nalgene bottles containing 0.5 ml of sterile sodium thiosulphate solution and transported on ice to the laboratory for analyses within 6 h of collection. The membrane filtration method was used for enumeration of presumptive Vibrio densities on thiosulfate citrate bile salt (TCBS) agar plates. Polymerase chain reaction (PCR) was then used to confirm the identities of the presumptive Vibrio species using the species-specific primers. The confirmed isolates were further subjected to molecular characterization to confirm their respective pathotypes. Presumptive Vibrio densities varied from 0 to 2.11 × 102 cfu/100 ml. Out of 300 confirmed Vibrio isolates; 13.3% (40/300) were Vibrio fluvialis, 22% (66/300) were confirmed to be Vibrio parahaemolyticus, and 24.7% (74/300) proved to be Vibrio vulnificus, and 40% (120/300) were other Vibrio species which were not assessed for in this study. The strains of Vibrio fluvialis were found to exhibit 100% resistance to Polymixin and Tetracycline. However, Gentamicin was active against all the three Vibrio species selected for the purpose of this research. The recovery of Vibrio species in the discharged effluents throughout the sampling period even in adequately disinfected effluents is not acceptable considering the fact that Vibrio is a pathogenic bacterium. The findings of this study underline the need for constant monitoring of the microbiological qualities of discharged effluents and might also be suggestive for a review of the disinfection methods used at the treatment works.
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- Date Issued: 2014
Prevalence of pathogenic Escherichia coli strains in the final effluents of four wastewater treatment plants in the Eastern Cape Province of South Africa
- Authors: Seti, Nozuko Zukiswa
- Date: 2014
- Subjects: Escherichia coli -- South Africa -- Eastern Cape , Bacterial diseases -- Pathogenesis , Sewage -- Purification -- South Africa -- Eastern Cape , Sewage disposal plants -- South Africa -- Eastern Cape , Whole effluent toxicity testing -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11286 , http://hdl.handle.net/10353/d1019808 , Escherichia coli -- South Africa -- Eastern Cape , Bacterial diseases -- Pathogenesis , Sewage -- Purification -- South Africa -- Eastern Cape , Sewage disposal plants -- South Africa -- Eastern Cape , Whole effluent toxicity testing -- South Africa -- Eastern Cape
- Description: Water is an essential need that stimulates health and well being. Increase in population size and urbanization negatively affect water resources due to high demands of effluent outputs. Wastewater is an important reservoir for Escherichia coli and can present significant acute toxicity if released into receiving water sources without being adequately treated. E. coli is used as indicator organism for the detection of faecal contamination. These strains have been considered to be one of the primary causes of diarrhoeal infections worldwide. The present study was conducted between September 2012 and June 2013 to assess the prevalence of pathogenic E. coli strains in the final effluents of four wastewater treatment plants in Chris Hani and Buffalo City Municipalities in the Eastern Cape Province of South Africa. Standard membrane filtration technique was used for bacteriological analysis and molecular based technique was used for identification of E. coli pathotypes. The results were recorded in colony forming units/100 ml. Faecal coliforms ranged between 0-9.6×10³ CFU/100 ml for the wwtp-Q and E. coli densities ranged between 0-8.4×10³ CFU/100ml. Faecal coliforms ranged between 4×10²-9.7×10³ CFU/100 ml for wwtp-M and E. coli densities ranged between 1.2×10¹-8.4×10³ CFU/100 ml. The wwtp-E showed to have bacterial counts of faecal coliforms ranging between 4.0×10³-8.2×10³ CFU/100 ml and E. coli densities ranging between 3.5×10¹-7.1×10³ CFU/100 ml. The WWTP-K in this study was only assessed for the presence of E. coli. Faecal coliforms were assessed by the other members of the group. This plant showed to have E. coli densities ranging between 0-7.5×10²CFU/100 ml. A total of 200 presumptive E. coli isolates were subjected to screening by conventional PCR in which (29%) of the wwtp-M isolates were positively identified as E. coli, (16%) of the wwtp-K, (22%) of the wwtp-Q and (34%) of the wwtp-E isolates were positively confirmed as E. coli. A total of 100 randomly selected E. coli isolates were characterised into different pathotypes. (16%) of positive isolates were detected as EPEC and 11% were detected as UPEC strains. There was no detection for the ETEC strains. Antibiotic susceptibility patterns of E. coli strains showed high levels of resistance to Penicillin G, Erythromycin, Tetracycline and Sulfamethoxazole. High levels of Susceptibility were observed in antibiotics such as Chloramphenicol, Amoxicillin and Tetracycline. The results of this study reveal that the plants were above the recommended Standard limit of zero CFU/100 ml for effluents meant to be discharge into receiving water sources. This study reveals inadequacy of the plants studied to produce effluents of acceptable quality.
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- Date Issued: 2014
Quality indices of the final effluents of two sub-urban-based wastewater treatment plants in Amathole District Municipality in the Eastern Cape Province of South Africa
- Authors: Gcilitshana, Onele
- Date: 2014
- Subjects: Whole effluent toxicity testing -- South Africa -- Eastern Cape , Sewage disposal plants -- South Africa -- Eastern Cape , Water -- Purification -- South Africa -- Eastern Cape , Effluent quality -- Testing , Viruses -- South Africa -- Eastern Cape , Water reuse -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11288 , http://hdl.handle.net/10353/d1019816 , Whole effluent toxicity testing -- South Africa -- Eastern Cape , Sewage disposal plants -- South Africa -- Eastern Cape , Water -- Purification -- South Africa -- Eastern Cape , Effluent quality -- Testing , Viruses -- South Africa -- Eastern Cape , Water reuse -- South Africa -- Eastern Cape
- Description: Worldwide, water reuse is promoted as an alternative for water scarcity, however, wastewater effluents have been reported as possible contaminants to surface water. The failure of some wastewater treatment processes to completely remove organic matter and some pathogenic microorganisms allows them to initiate infections. This manifests more in communities where surface water is used directly for drinking. To assess water quality, bacteria alone cannot be used as it may be absent in virus-contaminated water. This study was carried out to assess the quality of two wastewater treatment plant effluents from the Eastern Cape Province of South Africa. Physicochemical parameters and microbiological parameters like faecal coliforms, adenovirus, rotavirus, hepatitis A virus, norovirus and enterovirus were evaluated over a projected period of one year. Physicochemical parameters were measured on site using multiparameters, faecal coliforms enumerated using culture-based methods and viruses are detected using both conventional and real-time PCR. Physicochemical parameters like electrical conductivity, turbidity, free chlorine and phosphates were incompliant with the standards set by the Department of Water affairs for effluents to be discharged. Faecal coliform counts were nil for one plant (WWTP-R) where they correlated inversely (P < 0.01) with the high free chlorine. For WWTP-K, faecal coliforms were detected in 27% of samples in the range of 9.9 × 101 to 6.4× 104 CFU/100ml. From the five viruses assessed, three viruses were detected with Rotavirus being the most abundant (0-2034176 genome copies/L) followed by Adenovirus (0–275 genome copies/L) then Hepatitis A virus (0–71 genome copies/L) in the WWTP-K while none of the viruses was detected in WWTP-R. Species B, species C and Adv41 serotypes were detected from the May 2013 and June 2013 samples where almost all parameters were incompliant in the plant. The detection of these viruses in supposedly treated effluents is suggestive of these being the sources of contamination to surface water and therefore renders surface waters unsafe for direct use and to aquatic life. Although real-time PCR is more sensitive and reliable in detection of viruses, use of cell-culture techniques in this study would have been more efficient in confirming the infectivity of the viruses detected, hence the recommendation of these techniques in future projects of this nature.
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- Date Issued: 2014
Comparative in-vitro activities of trimethoprimsulfamethoxazole and the new fluoroquinolones against confirmed extended spectrum beta-lactamase producing Stenotrophomonas maltophilia in Nkonkobe Municipality, Eastern Cape environment
- Authors: Adeyemi, Oluwatosin Oluwakemi
- Date: 2012
- Subjects: Antibiotics , Microbial sensitivity tests , Drug resistance in microorganisms , Pathogenic microorganisms , Gram-negative bacterial infections
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11275 , http://hdl.handle.net/10353/d1007576 , Antibiotics , Microbial sensitivity tests , Drug resistance in microorganisms , Pathogenic microorganisms , Gram-negative bacterial infections
- Description: Stenotrophomonas maltophilia is increasingly emerging as an opportunistic pathogen of global concern. Due to its inherent resistance to several classes of antibiotics including carbapenems and its ability to acquire mobile resistance elements, treatment of infections caused by S. maltophilia is a constant challenge for clinicians. Trimethoprim-sulphamethoxazole (TMP-SMX) is the generally accepted antibiotic of choice for the treatment of infections caused by this organism, but resistance to the drug is increasingly being reported; hence, the need for alternative therapeutic options. In this study, the antimicrobial susceptibility profile of 110 commensal S. maltophilia isolates obtained from Nkonkobe municipality, Eastern Cape Province, Republic of South Africa was investigated. Twenty-one antibiotics including TMP-SMX and the newer fluoroquinolones; levofloxacin, gatifloxacin and moxifloxacin were included in the antibiotic panel. About 63.4 percent of the isolates were susceptible to TMP-SMX with a resistance rate of 28.2 percent. The fluoroquinolones were more effective with susceptibilities ranging from 76 percent to 94.7 percent. Resistance to the fluoroquinolones ranged from 1.3 percent to 2.7 percent. Levofloxacin was the most effective fluoroquinolone tested. Phenotypic dectection of extended spectrum β-lactamases (ESBLs) showed double disc synergy test (DDST) positivity in 59.5 percent of the isolates. Cefepime was the most sensitive indicator cephalosporin in the DDST with 77.3 percent of suspected ESBL-producing isolates showing cefepime-clavulanic acid synergy. Isolates exhibited nine different ESBL phenotypes, however, PCR amplification of the bla genes revealed four isolates that possessed genes belonging to the CTX-M group (CTX-M-1 and CTX-M-8 groups). ESBL genes are usually carried on mobile elements such as plasmids and transposons which may also bear genes that mediate resistance to aminoglycosides, tetracyclines, TMP-SMX and fluoroquinolones. ESBL positive isolates appeared more susceptible to the fluoroquinolones compared to TMP-SMX but there was no significant relationship between ESBL production and susceptibility to these drugs (p > 0.05). The newer fluoroquinolones are a possible alternative treatment option for S. maltophilia infections in this environment but further studies and clinical investigations are needed to determine the in vivo efficacy of these drugs.
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- Date Issued: 2012
Evaluation of the possible application of cowpea genotypes in the farming systems of the Eastern Cape Province, South Africa
- Authors: Adeyemi, Samson Adebowale
- Date: 2012
- Subjects: Cowpea -- South Africa -- Eastern Cape , Cowpea , Plant diversity , Cowpea -- Genetics , DNA fingerprinting of plants
- Language: English
- Type: Thesis , Masters , MSc (Biochemistry)
- Identifier: vital:11274 , http://hdl.handle.net/10353/d1007539 , Cowpea -- South Africa -- Eastern Cape , Cowpea , Plant diversity , Cowpea -- Genetics , DNA fingerprinting of plants
- Description: Characterization studies on the genetic diversity among cultivated cowpea (Vigna unguiculata (L.) varieties are valuable tools to optimize the use of available genetic resources by farmers, local communities, researchers and breeders. Eight cowpea (Vigna unguiculata (L.) genotypes ( Vegetable cowpea, Ivory grey, Okhalweni, Fahari, Fahari dark, 97K-1069-8, IT93K-73h, and 129-3) were subjected to molecular, morphological and agronomical characterization. DNA amplification fingerprinting markers were used to evaluate the genetic diversity among the eight genotypes. Nine random arbitrary primers were used to screen the eight genotypes to assess their ability to reveal polymorphisms in cowpea, and seven of them were selected for use in characterizing the total sample. A total of 43 bands were generated which are all polymorphic. On the average, the primers generated a total of 6.1 polymorphic bands. The resulting data-matrix included 43 analysed bands with a total of 344 characters. Neighbour joining analysis was used to generate the dendrogram, clustering the genotypes into two groups at an agglomerate coefficient of 0.30 irrespective of their geographical origins. The results also showed the presence of significant differences in morphological and quality traits among the genotypes. Fahari yielded the highest concentration of crude protein (46.51 mg/mg dry leaf) while Vegetable cowpea yielded the lowest (24.41 mg/mg dry leaf). The influence of manure was also found to be effective by increasing the crude protein content of the genotypes as shown by Fahari dark with an average of 53.53 mg/mg dry leaf as opposed to 39.85 mg/mg dry leaf without manure application. Although some small clusters grouped accessions of the same growth habits, a general lack of agreement between clustering and morphological features was observed. It can therefore be concluded that the significant differences between the molecular genetic analysis using DAF-PCR markers, morphologic characters and yield traits can be important tools to identify and discriminates the different cowpea genotypes.
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- Date Issued: 2012
Productions of high quality wastewater final effluents remain a challenge in the Eastern Cape Province of South Africa
- Authors: Gusha, Siyabulela Stability
- Date: 2012
- Subjects: Water-supply, Rural -- Health aspects -- South Africa , Pathogenic microorganisms -- South Africa -- Eastern Cape , Water-supply, Rural -- South Africa -- Eastern Cape , Effluent quality -- Testing , Sewage disposal plants -- South Africa -- Eastern Cape , Escherichia coli
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11265 , http://hdl.handle.net/10353/489 , Water-supply, Rural -- Health aspects -- South Africa , Pathogenic microorganisms -- South Africa -- Eastern Cape , Water-supply, Rural -- South Africa -- Eastern Cape , Effluent quality -- Testing , Sewage disposal plants -- South Africa -- Eastern Cape , Escherichia coli
- Description: Water is an indispensible and yet a difficult resource to be renewed, thus water scarcity has become one of the major challenges faced worldwide, with the Southern regions of Africa being the most impacted and affected, especially the Eastern Cape Province of South Africa where rural communities depend on receiving waterbodies that are often negatively impacted by wastewater final effluents. This present study was conducted between August and December 2010 to assess the physicochemical and microbial qualities of the final effluents of peri-urban and rural communities based wastewater treatment plants in the Eastern Cape Province. The physicochemical parameters were determined on site and in the laboratory, while bacteriological qualities were determined using culture based techniques. The virological qualities were determined by molecular methods using reverse transcriptase polymerase chain reaction for the target RNA virus and the conventional polymerase chain reaction for the target DNA virus. For both wastewater treatment plants, the physicochemical parameters ranged as follows: chemical oxygen demand (5.95-45 mg/L); total dissolved solids (114.5-187.0 mg/L); salinity (0.12-0.20 psu); temperature (14.2-25.7oC); pH (6.0-7.6); nitrate and nitrites (1.55-6.7 mg/L and 0.023-1.15 mg/L respectively); biological oxygen demand (3.5-7.8 mg/L); turbidity (1.49-6.98 NTU); and chlorine residual (0-2.97 mg/L). Feacal indicator bacteria counts ranged as follows: feacal coliforms (0-1.25×104 cfu/100 ml); total coliforms (0-3.95×104 cfu/100 ml); and enterococci (0-5.0×103 cfu/100 ml). xviii Seventy five percent of the rural community based plant and 80 percent of the peri-urban community based plant were positive for coxsackie A virus, while hepatitis A virus was detected in all the rural community based plant 80 percent of the peri-urban community based plant. This study suggests the need for intervention by appropriate regulatory agencies to ensure regular monitoring of the qualities of final effluents of wastewater treatment facilities in the Eastern Cape Province and ensure compliance to established guidelines.
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- Date Issued: 2012
Studies on bioflocculant production by a consortium of two bacterial species belonging to the Methylobacterium and Actinobacterium genera
- Authors: Ntsaluba, Luvuyo
- Date: 2012
- Subjects: Flocculation , Actinobacteria , Methylobacterium , Water -- Purification
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11266 , http://hdl.handle.net/10353/482 , Flocculation , Actinobacteria , Methylobacterium , Water -- Purification
- Description: Bioflocculants produced by two identified bacteria: Actinobacterium sp. Mayor and Methylobacterium sp. Obi were investigated with regard to their physicochemical and flocculating characteristics. The two strains were later combined to form a consortium for further studies. The optimum culture conditions for the bioflocculant production were similar for all strains except in the case of Actinobacterium sp. Mayor and the consortium, where glucose was replaced by sodium carbonate as a carbon source. Multi-nitrogen source was the best nitrogen source compare to individual sources for both strains. The divalent cation, Ca2+ proved to be a better flocculating activity stimulus for all produced bioflocculants in this study. The optimum flocculating activities obtained for both individual strains and the consortium were all at alkaline pH. The yield of purified bioflocculant produced by the consortium was 8.203 g/l, while 4.190 g/l and 4.610 g/l were recovered for single strains of Actinobacterium sp. Mayor and Methylobacterium sp. Obi respectively. Further characterization of pure bioflocculants revealed that a bioflocculant dosage of 0.3 mg/ml resulted in the highest flocculating activity for both individual strains while 1.0 mg/ml of the bioflocculant produced by the consortium was required to enhance maximum flocculating efficiency. These bioflocculants proved to be all thermo stable at a temperature range of 20 to 900°C with a heating rate of 10oC/min under a constant flow of nitrogen gas. The presence of functional groups normally required for bioflocculation such as hydroxyl, carboxyl and amino was also detected. The findings of this study suggest that the producedbioflocculants can be utilized as excellent substitutes for harmful synthetic flocculants in both water and wastewater treatments as well as in other industrial applications.
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- Date Issued: 2012
Assessment of the antibacterial properties of n-Hexane extract of Cocos Nucifera and its interactions with some conventional antibiotics
- Authors: Akinyele, Taiwo Adesola
- Date: 2011
- Subjects: Coconut palm , Microbial sensitivity tests , Gram-negative bacterial infections , Vibrio infections , Antibiotics , Hexane , Extracts
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11245 , http://hdl.handle.net/10353/416 , Coconut palm , Microbial sensitivity tests , Gram-negative bacterial infections , Vibrio infections , Antibiotics , Hexane , Extracts
- Description: Cocos nucifera belong to the family Aracaceae (palm Family). The English name is coconut and it is used extensively as medicinal remedies against infections such as urinary tract infections, gastro intestinal infections, skin and wound infections. The in vitro antibacterial (including anti-listerial and anti-vibrio) properties as well as the evaluation of the combination potentials of the plant extract with six front-line antibiotics were evaluated in this study using standard procedures. The in vitro anti-listerial properties of the crude aqueous and n-Hexane extract of the husk of Cocos nucifera were carried out against 37 Listeria isolates. Twenty-nine of the test organisms were susceptible to the aqueous extract while thirty were susceptible to the n-Hexane extract both at the screening concentration of 25 mg/ml. Minimum Inhibitory Concentration (MIC) values for all the susceptible bacteria ranged between 0.6 - 5.0 mg/ml. For the aqueous extract, average log reduction in viable cell count ranged between 0.32 Log10 and 4.8 Log10 CFU/ml after 8 hours interaction in 1 × MIC and 2 × MIC. For the n-Hexane extract, the log reduction ranged between 2.4 Log10 and 6.2 Log10 CFU/ml after 8 hours interaction in 1 × MIC and 2 × MIC. The time-kill characteristics of the two extracts suggest that at higher concentration (2 × MIC) and longer duration of interaction (8 hr), more bacteria were killed. In vitro anti-vibrio and antibacterial properties experiment revealed that of all the 45 vibrio and 25 bacteria strains that was tested, 37 were susceptible to the aqueous extract and 38 to the n-Hexane extract, while 17 were susceptible to the aqueous extract and 21 to the n-Hexane extract. Minimum Inhibitory Concentration (MIC) values for all the susceptible bacteria ranged between 0.3 - 5.0 mg/ml. viii The time kill studies revealed that for the aqueous extract, average log reduction in viable cell count in time kill assay ranged between 0.12 Log10 and 4.2 Log10 CFU/ml after 8 hr interaction at 1 × MIC and 2 × MIC. For the n-Hexane extract, the log reduction ranged between 0.56 Log10 and 6.4 Log10 CFU/ml after 8 hr interaction in 1 × MIC and 2 × MIC. In the test for the combination interactions, the checkerboard method revealed synergy of 67% and indifferent of 33%, while the time kill assay detected synergy in 72% and indifferent in 28% of the combinations tested. The synergy detected was not specific to any of the antibiotics or the Gram reaction of the bacteria, and no antagonism was detected. We conclude that the aqueous and n-Hexane extract of the husk of C. nucifera contains potential broad spectrum antibiotics resistance modulating compounds that could be relevant in the treatment of infections caused by these pathogens. In addition, the husk which is being discarded as agro waste will opens up a vista of opportunities for utilization for therapeutic purposes
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- Date Issued: 2011