Browsing by Author "Obayori, Oluwafemi Sunday"

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    Biodegradation of Used Engine Oil by a Methylotrophic Bacterium, Methylobacterium Mesophilicum Isolated from Tropical Hydrocarbon-contaminated Soil
    (Taylor and Francis: Petroleum Science and Technology Journal, 2014-12) Salam, Lateef B.; Obayori, Oluwafemi Sunday; Raji, S. A.
    A Gram-negative facultatively methylotrophic bacterium putatively identified as Methylobacterium mesophilicum strain RD1 displayed extensive degradative ability on used engine oil (SAE 40W) in liquid cultures. The rate of degradation of used engine oil (1274.85 mg L−1) by the isolate, for the first 12 days and the last 9 days were 65 and 40 mg L−1 d−1, respectively. Gas chromatographic (GC) analyses of residual used engine oil revealed that 61.2% and 89.5% of the initial concentration of the used engine oil were degraded within 12 and 21 days. GC fingerprints of the used engine oil after 12 days of incubation showed total disappearance of C15, C23, C24, C25, and C26 hydrocarbon fractions as well as drastic reductions of C13, C14, C16, and PAHs fractions such as C19-Anthracene and C22-Pyrene. At the end of 21 days’ incubation, total disappearance of C17-pristane, C22-pyrene, one of the C19-anthracene, and significant reduction of C18-phytane (96.8%) fractions were observed. In addition, less than 10% of Day 0 values of medium fraction ranges C13, C14, and C16 were discernible after 21 days. This study has established the potential of Methylobacterium mesophilicum strain RD1 in degradation of aliphatic, aromatic, and branched alkane components of used engine oils.
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    Biodegradation of Used Engine Oil by a Methylotrophic Bacterium, Methylobacterium Mesophilicum Isolated from Tropical Hydrocarbon-contaminated Soil
    (Petroleum Science and Technology, 2014-12) Salam, Lateef B.; Obayori, Oluwafemi Sunday; Raji, S. A.
    A Gram-negative facultatively methylotrophic bacterium putatively identified as Methylobacterium mesophilicum strain RD1 displayed extensive degradative ability on used engine oil (SAE 40W) in liquid cultures. The rate of degradation of used engine oil (1274.85 mg L−1) by the isolate, for the first 12 days and the last 9 days were 65 and 40 mg L−1 d−1, respectively. Gas chromatographic (GC) analyses of residual used engine oil revealed that 61.2% and 89.5% of the initial concentration of the used engine oil were degraded within 12 and 21 days. GC fingerprints of the used engine oil after 12 days of incubation showed total disappearance of C15, C23, C24, C25, and C26 hydrocarbon fractions as well as drastic reductions of C13, C14, C16, and PAHs fractions such as C19-Anthracene and C22-Pyrene. At the end of 21 days’ incubation, total disappearance of C17-pristane, C22-pyrene, one of the C19-anthracene, and significant reduction of C18-phytane (96.8%) fractions were observed. In addition, less than 10% of Day 0 values of medium fraction ranges C13, C14, and C16 were discernible after 21 days. This study has established the potential of Methylobacterium mesophilicum strain RD1 in degradation of aliphatic, aromatic, and branched alkane components of used engine oils.
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    Degradation of crude oil (Escravos light) by Pseudomonas strains isolated from poultry droppings and cow dung.
    (LASU Journal of Research and Review in Science, 2017-12) Obayori, Oluwafemi Sunday; Salam, Lateef B.; Ogunmakinwa, Olubusola Olayinka; Ogunleye, Moyosore Adedolamu
    Introduction: Poultry manure and cow dung have been established as potential material for the bioremediation of petroleum polluted sites, with emphasis on nutrient addition. Aim: Our aim was to isolate from poultry droppings and cow dung bacteria with ability to degrade petroleum hydrocarbons. Materials and Methods: Bacteria were isolated from poultry droppings and cow dung by continuous enrichment and vapor transfer techniques. Petroleum utilization by each isolate was confirmed in carbon free medium containing Escravos crude oil (1%). The two best isolates were selected for further study. Isolates were identified by Analytical Profile Index (API). Antibiotic sensitivity was determined by multidisc (Abitek Multidisc, UK). Growth was assayed in broth culture by plate count. Residual oil was determined by Gas Chromatography equipped with Flame Ionisation detector (GC-FID). Results: The isolates were putatively identified as Pseudomonas putida (MP2) and Pseudomonas sp. (MC4). Both isolates were susceptible to ciprofloxacin and chloramphenicol and tarivid. They resisted amoxicillin and gentamycin, augmentin, sparfloxacin and septrin. The growth rates were 0.17 and 0.23/day for strains MP2 and MC4 respectively, while the organisms degraded 88.39% and 89.06 % of crude oil respectively in 20 days. Aliphathic hydrocarbons in the range C11 to C22 were mostly reduced to less than 20%, while C22 – C26 disappeared completely within the same period in both cases. Conclusion: Bacteria capable of extensive degradation of Escravos crude oil were isolated from poultry droppings and cow dung. Such isolates could be veritable candidates for bioaugmentation of hydrocarbon polluted environmental compartments.
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    Fluorene biodegradation potentials of Bacillus strains isolated from tropical hydrocarbon-contaminated soils
    (Academic Journals : African Journal of Biotechnology, 2014-03-24) Salam, Lateef B.; Obayori, Oluwafemi Sunday
    Two fluorene-degrading Gram-positive Bacillus strains, putatively identified as Bacillus subtilis BM1 and Bacillus amyloliquefaciens BR1 were isolated from hydrocarbon-and asphalt-contaminated soils in Lagos, Nigeria. The polluted soils have a relatively high total hydrocarbon content (16888.9 and 9923.1 mg/kg, respectively), very low concentrations of macronutrients and the total organic carbon was less than 4%. The two strains tolerated NaCl concentration of up to 7% while strain BR1 exhibited moderate growth at 10%. Shared resistance to ceftriazone and cotrimozaxole were exhibited by both strains while only strain BM1 was resistant to both amoxycilin and streptomycin. The rate of degradation of fluorene (50 mg/L) by the two isolates, after 30 days of incubation were 0.09 and 0.08 mg/L/h for strains BM1 and BR1, respectively. Gas chromatographic analyses of residual fluorene, revealed that 56.9 and 46.8% of 50 mg/L fluorene was degraded in 12 days by strains BM1 and BR1. However, after 21 days on incubation, 86 and 82% of 50 mg/L fluorene were degraded by strains BM1 and BR1, respectively. To the best of our knowledge, this is the first report highlighting flourene degradation potential of Bacillus strains isolated from tropical African environment
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    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 Oladipo
    Profiling 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 resurgence
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    Remarkable shift in structural and functional properties of an animal charcoalpolluted soil accentuated by inorganic nutrient amendment
    (Journal of Genetic Engineering and Biotechnology, 2020) Salam, Lateef B.; Obayori, Oluwafemi Sunday
    Background: Soils polluted with animal charcoal from skin and hide cottage industries harbour extremely toxic and carcinogenic hydrocarbon pollutants and thus require a bio-based eco-friendly strategy for their depuration. The effects of carbon-free mineral medium (CFMM) amendment on hydrocarbon degradation and microbial community structure and function in an animal charcoal-polluted soil was monitored for 6 weeks in field moist microcosms consisting of CFMM-treated soil (FN4) and an untreated control (FN1). Hydrocarbon degradation was monitored using gas chromatography-flame ionization detector (GC-FID), and changes in microbial community structure were monitored using Kraken, while functional annotation of putative open reading frames (ORFs) was done using KEGG KofamKOALA and NCBI’s conserved domain database (CDD). Results: Gas chromatographic analysis of hydrocarbon fractions revealed the removal of 84.02% and 82.38% aliphatic and 70.09% and 70.14% aromatic fractions in FN4 and FN1 microcosms in 42 days. Shotgun metagenomic analysis of the two metagenomes revealed a remarkable shift in the microbial community structure. In the FN4 metagenome, 92.97% of the population belong to the phylum Firmicutes and its dominant representative genera Anoxybacillus (64.58%), Bacillus (21.47%) and Solibacillus (2.39%). In untreated FN1 metagenome, the phyla Proteobacteria (56.12%), Actinobacteria (23.79%) and Firmicutes (11.20%), and the genera Xanthobacter (9.73%), Rhizobium (7.49%) and Corynebacterium (7.35%), were preponderant. Functional annotation of putative ORFs from the two metagenomes revealed the detection of degradation genes for aromatic hydrocarbons, benzoate, xylene, chlorocyclohexane/chlorobenzene, toluene and several others in FN1 metagenome. In the FN4 metagenome, only seven hydrocarbon degradation genes were detected. Conclusion: This study revealed that though CFMM amendment slightly increases the rate of hydrocarbon degradation, it negatively impacts the structural and functional properties of the animal charcoal-polluted soil. It also revealed that intrinsic bioremediation of the polluted soil could be enhanced via addition of water and aeration
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    Structural and functional metagenomic analyses of a tropical agricultural soil
    (Spanish Journal of Soil Science, 2019-01-21) Salam, Lateef B; Obayori, Oluwafemi Sunday
    Understanding the intricate link between the soil microbiota and their metabolic functions is important for agricultural and ecological processes and could be used as a biomarker of soil health. To understand the relationship between soil microbial community structure and functions, a soil microcosm designated 2S (agricultural soil) was set up. Metagenomic DNA was extracted from the soil microcosm and sequenced using Miseq Illumina next generation sequencing and analysed for their structural and functional properties. Structural analysis of the soil microcosm by MG-RAST revealed 40 phyla, 78 classes, 157 orders, 273 families and 750 genera. Actinobacteria (54.0%) and Proteobacteria (17.5%) are the dominant phyla while Conexibacter (8.38%), Thermoleophilum (7.40%), and Streptomyces (4.14%) are the dominant genera. Further assignment of the metagenomics using Cluster of Orthologous Groups (COG), Kyoto Encyclopedia of Genes and Genomes (KEGG), GhostKOALA, and NCBI’s CDD revealed diverse metabolic pathways utilized by the microbial community for the metabolism of carbohydrates, amino acids, lipids, biosynthesis of secondary metabolites and resistance to antibiotics. Taxonomic analysis of the annotated genes also revealed the preponderance of members of Actinobacteria and Proteobacteria. This study has established that members of the phyla Actinobacteria and Proteobacteria are the key drivers of the majority of important metabolic activities in the soil ecosystem and are thus an integral part of the soil microbial community.