Browsing by Author "Ogunyemi, Adewale K."
Now showing 1 - 6 of 6
Results Per Page
Sort Options
Item Cassava Wastewater and Solid Waste Leachate as Cyanogenic Substrates for the Growth of Nitrile and Linamarin-Utilizing Bacteria(Journal of Tropical Life Science, 2019) Ogunyemi, Adewale K.; Samuel, Titilola A.; Ilori, Mathew O.; Amund, Olukayode O.The direct discharge of wastewaters containing cyanogenic compounds poses severe health hazards, hence this study aimed to establish the biodegradative potential of nitrile and linamarin utilizing bacterial strains in the degradation of cyanogens in cassava wastewaters (CWW) and solid waste leachates (SWL). Glutaronitrile-utilizing bacterial strains (Bacillus sp. strain WOD8 KX774193 and Corynebacterium sp. strains WOIS2 KX774194) were isolated from solid waste leachates while linamarin-utilizing bacteria strains (Bacillus pumilus strain WOB3 KX774195 and Bacillus pumilus strain WOB7 KX774196) were isolated from cassava wastewaters. They were identified on the basis of morphological and biochemical characteristics, microscopic and 16S rRNA gene sequencing. Microbial growth assessment coupled with pH changes were performed under aerobic batch conditions. Growth was evaluated at intervals (2 days) by the intensity of turbidity (O.D. 600 nm) in CWW and SWL media. The doubling times of strains WOD8 and WOIS2 when grown on CWW and SWL (without supplementing mineral salts medium) were 12.83 and 10.83 d (specific growth rate, µ: 0.054 and 0.064 d-1) and 20.38 and 17.77 d (µ: 0.034 and 0.039 d-1) respectively. Also, strains WOD8 and WOIS2 grew on supplemented CWW and SWL with doubling times of 10.04 and 9.9 d (µ: 0.069 and 0.070 d-1) and 16.12 and 16.12 d (µ: 0.043 and 0.043 d-1) respectively. Similarly, the doubling times of strains WOB3 and WOB7 when grown on CWW and SWL (without supplementing mineral salts medium) were 8.25 and 7.53 d (µ: 0.084 and 0.092 d-1) and 8.66 and 9.90 d (µ: 0.080 and 0.070 d-1) respectively. Whereas, the same strains had doubling times of 6.30 and 5.78 (µ: 0.11 and 0.12 d-1) and 6.30 and 9.24 (µ: 0.11 and 0.075 d-1) respectively when grown on supplemented CWW and SWL. It would appear that CWW has the highest potential as a natural growth substrate than SWL, and its use for biomass production may contribute to a reduction in the overall environmental impact generated by discarding cyanogenic residues.Item CHARACTERIZATION OF LINAMARIN-UTILIZING BACTERIAL STRAINS ASSOCIATED WITH DETOXIFICATION OF CYANOGENS IN WASTE EFFLUENTS(Malaysian Applied Biology Journal, 2019-06-30) Ogunyemi, Adewale K.; Samuel, Titilola A.; Amund, Olukayode O.; Ilori, Matthew O.The cyanide molecule is one of the dominant pollutants in the environment. This study aimed to isolate and identify the bacterial strains capable of utilizing linamarin and to assess their roles in the detoxification of cyanogenic substances in waste effluents in Lagos, Nigeria. Two bacterial strains, Bacillus pumilus strain WOB3 KX774195 and Bacillus pumilus strain WOB7 KX774196 were isolated from cassava wastewater samples by standard microbiological procedure. They were identified on the basis of morphological and biochemical characteristics and 16S rRNA gene sequencing. Microbial growth assessment was performed in triplicates under aerobic batch conditions. The generation times of strains WOB3 and WOB7 were 40.71 and 10.88 d; with specific growth rates of 0.025 and 0.064 d-1 respectively on linamarin. Strain WOB3 had maximum growth of 0.552 (OD600nm) by day 12 at pH 6.2. Likewise, strain WOB7 recorded optimum growth of 1.276 (OD600 nm) by day 10 at pH 6.4. The maximum values obtained for linamarase activities by WOB3 and WOB7 were 3.3 x 10-2 mgmL-1min-1 and 7.61 x 10-2 mgmL-1min-1 respectively. The results from this study suggest that the bacterial isolates possess degradative capacities, which could be deployed in the bioremediation of cassava processing wastes.Item Genotoxicity Evaluation of Landfill Solid Leachates from Waste Dumpsite in Lagos State, Nigeria Using the Allium cepa Assay(Plant and Animal Research Journal, 2018-04) Ogunyemi, Adewale K.; Samuel, Aderonke Titilol; Amund, Olukayode O.; Ilori, Matthew O.The management of municipal landfill’s leachate is considered one of the most significant environmental issues. Potential mutagenic and genotoxic effects of solid waste leachates (SWL) were investigated using the Allium cepa root meristematic cells assay technique. In Allium root growth inhibition test, experimental onion bulbs were cultivated in various concentrations of the SWL and distilled water was used as a negative control. The root tips from the treated bulb were processedby orcein squash technique after 72 h. The mean lengths of root bundles were obtained andeffective concentration (EC) values calculated. Some of the physicochemical properties of the WL were also determined. The A. cepa assay was carried out at concentrations of 0.05, 0.1, 2.0, 5, 10, 20, 50 and 100% of the WL. There was a statistically different (p < 0.05), concentrationdependent inhibition of onion root growth and mitotic index, and induction of chromosomal aberrations in the onion test. The results of the physicochemical analysis revealed that the concentrations of some parameters were above the maximum permissible limit set by the world health organization (WHO) and could partly be correlated with the toxicity of wastewater. The landfill leachates pose a risk to human health and the environment in general. Hence, ecotoxicity/genotoxicity assays would be useful in leachate risk assessment when coupled with physicochemical analysis.Item Isolation and characterisation of nitrilase producing Aspergillus species recovered from solid waste leachates at two dump sites in Lagos, Nigeria(Malaysian Journal of Microbiology, 2020) Ogunyemi, Adewale K.; Ogunyemi, Bukola C.; Ategun, Abiola L.; Iwalokun, Bamidele A.; Ike, Joseph I.; Ilori, Matthew O.; Amund, Olukayode O.Aims: Nitrile compounds are cyanogenic intermediates, products, byproducts and waste products of agriculture, chemical and pharmaceutical industries and fossil fuels degradation. The enzymatic hydrolysis of nitriles to non-toxic carboxylic acids or amides plays an increasingly important role in environment remediation. This study aimed at exploring the potential of Aspergilli in the detoxification nitrile compounds at two selected dump sites in Lagos, Nigeria. Methodology and results: Decomposing solid waste leachate samples (SWL) were randomly collected at two selected dump sites namely Olusosun (Ojota) and Isolo (Oke-Afa). Samples per site were pooled, processed by selective enrichment and screened for the presence of Aspergilli by culture technique and intergenic spacer sequencing (ITS). Biomass generation and pH changes in the culture fluids were monitored at 4-days interval by dry weight measurements. Nitrilase production was determined spectrophotometrically. Two nitrilase producing Aspergillus strains: Aspergillus fumigatus strain WO2 with accession number MF78882 and Aspergillus niger strain WO7 with accession number MH542673 were identified. Growth investigation revealed biomass generations of 17.8 g and 23.8 g dry weight per one liter media for A. fumigatus strain WO2 and A. niger strain WO7 respectively. Progressive pH monitoring showed decline from 7.2 to 4.5 and 7.2 to 6.2 was obtained for strains WO2 and WO7 respectively, during nitrilase production at different yields of 0.0150 and 0.0161 mg/mL/min respectively. Conclusion, significance and impact of study: This study supports the studied dump sites as important sources of nitrilase-producing A. fumigatus and A niger strains with potentials as cost-effective environmental bioremediation agents in Nigeria.Item NITRILE-METABOLIZING BACTERIAL STRAINS ASSOCIATED WITH MUNICIPAL WASTE TIPS IN THE LAGOS METROPOLIS, NIGERIA(UWM OLSZTYN, 2019) Ogunyemi, Adewale K.; Samuel, Titilola A.; Amund, Olukayode O.; Ilori, Matthew O.Cyanide is one of the dominant pollutants in the environment. This study aimed at exploring the potential of microbes in the detoxification of cyanogenic substances. Bacillus sp. WOD8 KX774193 and Corynebacterium sp. WOIS2 KX774194 strains were isolated from solid waste leachates. The doubling times of strain WOD8 and strain WOIS2 when grown on glutaronitrile and benzonitrile (without supplementing glucose) were 12.2 and 7.86 d (specific growth rate, μ: 0.057 and 0.088 d-1) and 15.75 and 13.33 d (specific growth rate, μ: 0.044 and 0.052 d-1) respectively. Also, strains WOD8 and WOIS2 grew on glutaronitrile and benzonitrile (with supplementing glucose) with doubling times of 9.76 and 7.62 d (μ: 0.071 and 0.091 d-1) and 10.5 and 8.15 d (μ: 0.066 and 0.085 d-1) respectively. The results from the present study suggest that the nitrile-metabolizing capabilities of these bacterial isolates can potentially be explored for the degradation and bioremediation of nitrile contamination in the environment.Item Potentials of microorganisms associated with plantain peels in the Lagos metropolis for biodegradation and bioconversion.(Faculty of Science, Obafemi Awolowo University, 2015) Ogunyemi, Adewale K.; Buraimoh, Olanike M.; Ogundele, M. T.; Adigun, J. A.; Olumuyiwa, E. O.; Amund, Olukayode O.; Okpuzor, J.; Odetunde, S. K.; Ehinmore, I. O.; Avungbeto, M. O.The role of microbes in the degradation of plantain derived-wastes and their potential to produce cellulolytic enzymes was assessed. Soil samples of decomposing waste piles were collected from two major plantain markets in the Lagos metropolis and analyzed for physicochemical properties, toxic heavy metal content and microbial populations. Findings revealed that the values of moisture content of the two soils varied between 7.27±0.04 and 8.06±0.19 %. M-12 site had the highest organic matter content of 6.89±0.14 %. A similar pattern was observed for nitrate, phosphate and chloride levels while some heavy metals were also detected in varying and high amounts. The highest viable bacterial counts was 58.0±2.9 x 104 cfu/g at MU and there were no fungi at the site whereas M-12 had a fungal count of 40.0±3.3 x 103 cfu/g. Out of the total of 34 isolates encountered, 8 isolates having maximum cellulase activities were selected for further studies by the primary screening technique. These test organisms were then evaluated by secondary screening for enzyme production. The test organisms were phenotypically and biochemically characterized and identified as Klebsiella pneumoniae spp pneumoniae (2 strains), Klebsiella pneumoniae spp ozaenae, Enterobacter aerogenes, Providencia alcalifaciens, Aspergillus flavus, Aspergillus fumigatus and Aspergillus niger respectively. Both the bacteria and moulds were found to be capable of utilizing lignin and cellulosic substrates for growth and for production of cellulolytic enzymes. It is suggested that such microorganisms could be useful in bioconversion of cellulosic substrates like plantain-derived wastes for biotechnological applications