Browsing by Author "Amund, Olukayode Oladipo"
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Item Impact of spent engine oil contamination on the antibiotic resistome of a tropical agricultural soil(Ecotoxicology, 2021-05) Salam, Lateef B.; Obayori, Oluwafemi Sunday; Ilori, Mathew Olusoji; Amund, Olukayode OladipoProfiling of hydrocarbon-contaminated soils for antibiotic resistance genes (ARGs) is becoming increasingly important due to emerging realities of their preponderance in hydrocarbon-inundated matrices. In this study, the antibiotic resistome of an agricultural soil (1S) and agricultural soil contaminated with spent engine oil (AB1) were evaluated via functional annotation of the open reading frames (ORFs) of their metagenomes using the comprehensive antibiotic database (CARD) and KEGG KofamKOALA. CARD analysis of AB1 metagenome revealed the detection of 24 AMR (antimicrobial resistance) gene families, 66 ARGs, and the preponderance (69.7%) of ARGs responsible for antibiotic efflux in AB1 metagenome. CARD analysis of 1S metagenome revealed four AMR gene families and five ARGs. Functional annotation of the two metagenomes using KofamKOALA showed 171 ARGs in AB1 and 29 ARGs in 1S, respectively. Majority of the detected ARGs in AB1 (121; 70.8%) and 1S (16; 55.2%) using KofamKOALA are responsible for antibiotic efflux while ARGs for other resistance mechanisms were also detected. All the five major antibiotic efflux pump systems were detected in AB1 metagenome, though majority of the ARGs for antibiotic efflux belong to the RND (resistance-nodulation-cell division) and MFS (major facilitator superfamily) efflux systems. Significant differences observed in the ARGs recovered from 1S and AB1 metagenomes were statistically validated (P < 0.05). SEO contamination is believed to be responsible for ARGs increase in AB1 metagenome via mechanisms of cross-resistance especially with efflux pumps. The detection of these ARGs is of great public health concern in this era of multidrug resistant isolates resurgenceItem Nitrilase gene detection and nitrile metabolism in two bacterial strains associated with waste streams in Lagos, Nigeria(Bulletin of the National Research Centre, 2022-05) Ogunyemi, Adewale Kayode; Buraimoh, Olanike Maria; Ogunyemi, Bukola Caroline; Samuel, Titilola Aderonke; Ilori, Matthew Olusoji; Amund, Olukayode OladipoBackground: The use of nitrile compounds is usually high, particularly in chemical industries, which calls for serious concern because of their relevance to the environment. The essential role of nitrilases in the bioremediation of harmful nitriles from environmental wastes cannot be overemphasized. The study aimed to unveil the biodegradative potentials of bacterial strains associated with the degradation of nitrile pollutants. Methods: Bacterial strains capable of utilizing glutaronitrile as the sole source of carbon and nitrogen were isolated from solid waste leachates by a selective enrichment culture technique. The test organisms were grown in mineral salts medium (MSM), and the metabolic products were determined using gas chromatography-fame ionization detection (GC-FID). The nitrilase gene was amplifed by polymerase chain reaction (PCR) and by using appropriate primers. Results: The growth studies showed that the test organisms grew on the two nitriles. The doubling times of 12.16 d and 9.46 d (specifc growth rate, µ=0.082 d−1 , 0.106 d−1 ) were obtained for each pure culture of Bacillus sp. srain WOD8 and Corynebacterium sp. srain WOIS2 on glutaronitrile (as single substrate), respectively. While the same strains had doubling times of 11.11 d and 10.00 d (µ=0.090 d−1 , 0.100 d−1 ) on benzonitrile (as single substrate). However, the mixed culture (comprising the two strains) had doubling times of 7.40 d and 7.75 d (µ=0.135 d−1 , 0.129 d−1 ) on glutaronitrile (as single and mixed substrates), respectively. While doubling times of 8.09 d and 8.71 d (µ=0.124 d−1 , 0.115 d−1 ) were obtained for the same mixed culture on benzonitrile (as single and mixed substrates). Based on gas chromatographic analysis, the residual glutaronitrile concentrations at day 16 for strains WOD8 and WOIS2 were 35.77 g L−1 (72.2%) and 9.30 g L−1 (92.5%), respectively, whereas the residual benzonitrile concentrations for the same strains were 27.39 g L−1 (78.8%) and 13.79 g L−1 (89.2%), respectively. For the mixed culture, residual glutaronitrile and benzonitrile concentrations at day 16 were 13.40 g L−1 (88.5%) and 10.42 g L−1 (91.5%), respectively, whereas for the mixed substrates (glutaronitrile and benzonitrile), 7.21 g L−1 (91.7%) and 4.80 g L−1 (94.2%) of residual glutaronitrile and benzonitrile concentrations were obtained by the same consortium. The gene for nitrilase involved in nitrile degradation was detected in the genome of the bacterial strains. The amplifed nitrilase gene gave PCR products of sizes 1400 bp and 1000 bp, as expected for strains WOD8 and WOIS2, respectively. 4-Cyanobutyric acid (4CBA), glutaric acid (GA), and benzoic acid (BA) were obtained as metabolites following nitrile degradation in vitro.Conclusion: These results revealed that strains WOD8, WOIS2 and the mixed culture (consisting of the two strains) have proven to have the capacity to metabolize nitriles (glutaronitrile and benzonitrile) as the carbon and nitrogen sources. However, the mixed culture had higher nitrile degradation rate as compared to each pure culture of the two test organisms. These results also provide insight into the evolutionary genetic origin of a nitrilase gene that encodes an enzyme that catalyzes nitrile degradation in these strains. Hence, the bacterial strains that harbor this kind of gene may be used as promising biological agents for the remediation of sites polluted with nitriles, thereby opening new perspectives for encouraging data for a bioremediation bioprocessItem Potentials of Hydrocarbon Utilization by Wood-Digesting Bacteria Isolated from the Lagos Lagoon, Nigeria(JOURNAL OF TROPICAL LIFE SCIENCE, 2020-02-01) Buraimoh, Olanike Maria; Ogunyemi, Adewale Kayode; Oyegbite, Isaac Edward; Amund, Olukayode Oladipo; Ilori, Matthew OlusojiThere is a continuous search for environmental–friendly methods to address oil-polluted environments, hence this study aimed to establish the potential of using tropical estuarine bacterial strains for degradation of crude oil in polluted environ-ment. Microbial degradation of hydrocarbons has been considered a promising, natural, less toxic and cost-effective technology. Lignocellulose-utilizing bacterial strains (Bacillus megaterium strain NOB, Streptomyces pseudogriseolus strain EOB and Paenibacillus sp. strains ROB) were isolated from decomposing wood residues in a tropical lagoon. They were identified on the basis of morphological and biochemical characteristics, observation under scanning electron microscope and 16S rRNA gene sequencing. Microbial growth assessment coupled with bio-surfactant production were performed in triplicates under aerobic batch conditions in Erlenmeyer flasks containing mineral salts medium fortified with trace elements and crude oil as the sole carbon source. The generation times of strains NOB, EOB and ROB were 28.3, 44.9 and 46.8 h respectively; with specific growth rates of 14.2, 8.9 and 8.6 h-1, respectively on crude oil. Gas chromatographic analysis of residual hydrocarbons from the growth cultures of isolates revealed that the three strains had degraded the oil by 89.34, 86.33 and 79.37%, respectively at the end of 21 days. The cell hydrophobicity of the bacterial strains also reached 83.6, 79.4 and 69.4%, respectively. The results from this study suggest that wood-digesting bacterial strains from a tropical lagoon possess hydrocarbon utilization capabili-ties. They could therefore have potentials for deployment in the bioremediation of petrochemical spills in polluted environments.Item Sustainable generation of bioethanol from sugarcane wastes by Streptomyces coelicolor strain COB KF977550 isolated from a tropical estuary(Scientific African, 2021-01-20) Buraimoh, Olanike Maria;; Ogunyemi, Adewale Kayode; Isanbor, Chukwuemeka; Aina, Oluwafemi Segun; Amund, Olukayode Oladipo; Ilori, Mathew Olusoji; Familoni, Oluwole BabafemiThe damaging effect and challenges associated with the use of fossil fuel is enormous and very costly. Biofuels could be obtained from plant biomass wastes which are known to be sources of environmental pollution and breeding grounds for vectors of diseases. Sugarcane bagasse was exploited as a renewable substrate for obtaining bioethanol using Streptomyces strain COB KF977550 as inoculum. Submerged aerobic batch fermentation was performed in flasks containing mineral salts medium supplemented with 5.0 g (w/v) sugarcane bagasse. Incubation was done in a shaker (150 rpm) at 30 oC for 21 days. Microbial growth was assessed by measurement of the optical density (O.D 600nm) at 3-day intervals. Fractional distillation was carried out in batch mode using a simple fractional distillation setup. Metabolic products were determined using GC-FID. Further analyses were performed using FTIR and GC-MS. The optical density of S.coelicolor strain COB KF977550 increased from 0.9 to 1.41. The GC-FID showed that 43.08 g/L ethanol was generated. Interestingly, the results showed the presence of diverse biochemicals released into the medium in addition to the main product ethanol. Ten carboxylic acids including formic acid, glycolic acid, tartaric acid, acetic acid, citric acid, oxalic acid, malic acid, lactic acid, n-valeric acid, and 3-hydroxybutyric acid were identified as biochemical organic acids by-products.