Browsing by Author "Nwinyi, Obinna C."

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    Aerobic Degradation of Naphthalene, Fluoranthene, Pyrene and Chrysene Using Indigenous Strains of Bacteria Isolated from a former Industrial Site
    (SENRA Academic Publishers, British Columbia, 2013) Nwinyi, Obinna C.; Picardal, Flynn W; An, Thuy T; Amund, Olukayode O.
    Four bacterial strains were isolated from a former industrial site contaminated with organic and inorganic pollutants for decades. The isolation was done using naphthalene as sole source of carbon and energy during the enrichment. 16S rRNA gene sequence analyses of the four isolates (OC1, OC2, OC3, and OC4) assigned the strains to the genus, Enterobacter (OC1) and Pseudomonas (OC2, OC3, and OC4). The degradation and growth behavior of the four isolates was investigated on naphthalene, fluoranthene, pyrene and chrysene. All the strains utilized naphthalene, fluoranthene, chrysene but pyrene partially, as sole sources of carbon and energy. The time course studies using relative concentration > 100ppm, >115ppm, > 89ppm and > 12 ppm for naphthalene, fluoranthene, pyrene and chrysene respectively, resulted in rapid exponential increases in cell numbers and concomitant disappearance of the test substrates. Naphthalene was degraded between the range of 25 % and 99%, while chrysene degradation ranged between of 35 and 69%, pyrene 4 - 21% and fluoranthene 7 -19 %. Our results suggest that contaminated, former industrial sites contain a capable microbial community that may be used for bioremediation of the site.
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    Biodegradation of selected polycyclic aromatic hydrocarbons by axenic bacterial species belonging to the genera Lysinibacillus and Paenibacillus
    (Springer International Publishing, 2017-09-01) Nwinyi, Obinna C.; Amund, Olukayode O.
    The quest for competent degraders of recalcitrant polynuclear aromatic hydrocarbons (PAHs) for use in sustainable bioremediation technology has justified the execution of this work. In this study, three bacterial strains (FB-1, FB-2 and FB-3) were isolated from a former industrial site in Bloomington, Indiana. The catabolic versatility of these obtained strains was evaluated on some selected PAH-naphthalene, anthracene, fluoranthene and pyrene. Using the 16S rRNA sequencing analyses, our strains belonged to the family Firmicutes whereby strain FB-1 was identified as Lysinibacillus sp. FB-1, strain FB-2 as Bacterium FB-2 and strain FB-3 as Lysinibacillus fusiformis FB-3. The biodegradation of the selected PAHs was determined using gas chromatography, and the calculated percentage utilization of the selected PAHs varied between 97 and 4%. We further determined the mean biodegradation rates for fluoranthene when supplemented with molasses. The mean biodegradation rates were between (mg L-1 ) 0.214 ± 0.006 and 0.318 ± 0.002, while MSfluoranthene only ranged from (mg L-1) 0.210 ± 0.056 to 0.437 ± 0.176. However, with ANOVA at 5% (P\0.05) there seemed to be no significant difference in the mean
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    Degradation of polynuclear aromatic hydrocarbons by two strains of Pseudomonas
    (SBM, 2016-09) Nwinyi, Obinna C.; Ajayi, Oluseyi O.; Amund, Olukayode O.
    The goal of this investigation was to isolate competent polynuclear aromatic hydrocarbonsdegraders that can utilize polynuclear aromatic hydrocarbons of former industrial sitesat McDoel Switchyard in Bloomington, Indiana. Using conventional enrichment methodbased on soil slurry, we isolated, screened and purified two bacterial species strains PB1 andPB2. Applying the ribotyping technique using the 16S rRNA gene analysis, the strains wereassigned to the genus Pseudomonas (Pseudomonas plecoglossicida strain PB1 and Pseudomonassp. PB2). Both isolates showed promising metabolic capacity on pyrene sprayed MS agarplates during the preliminary investigations. Using time course studies in the liquid culturesat calculated concentrations 123, 64, 97 and 94 ppm for naphthalene, chrysene, fluroantheneand pyrene, P. plecoglossicida strain PB1 and Pseudomonas sp. PB2 showed partial utilizationof the polynuclear aromatic hydrocarbons. Naphthalene was degraded between 26% and40%, chrysene 14% and 16%, fluroanthene 5% and 7%; pyrene 8% and 13% by P. plecoglossicidastrain PB1 and Pseudomonas sp. PB2 respectively. Based on their growth profile, we developeda model R2= 1 to predict the degradation rate of slow polynuclear aromatic hydrocarbon-degraders where all the necessary parameters are constant. From this investigation, weconfirm that the former industrial site soil microbial communities may be explored for thebiorestoration of the industrial site.
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    Physiological behavior of newly isolated Bacterium CB1 and Stenotrophomonas maltophilia strain CB2 on Chrysene, Pyrene, Naphthalene and Fluoranthene
    (Romanian Biotechnological Letters, 2017) Nwinyi, Obinna C.; Amund, Olukayode O.; Chinedu, Shalom N.; Chioma, NWANKWO M.
    The biodegradability of some polycyclic aromatic hydrocarbons were studied in liquid culture media using bacterial strains (Bacterium CB1 and Stenotrophomonas maltophilia strain CB2) isolated from a former industrial site contaminated with organic and inorganic contaminants. The enrichment experiment was done with chrysene. The partial 16S rRNA gene analyses of Bacterium CB-1 possessed 100% similarity to an uncultured bacterium clone nbt020a while Stenotrophomonas maltophilia strain CB2 had 99% similarity to Paenibacillus sp. Y412MC10. Bacterium CB1 and Stenotrophomonas maltophilia strain CB2 degraded naphthalene between the range of 27% and 42%, chrysene 47% and 12%, fluoranthene 5% and 16%, pyrene 12% and 17% respectively. The strains utilized the test compounds as sole source of carbon and energy. As anticipated, the controls (abiotic and killed) losses were insignificant. The residual PAH obtained in some cases correlated to an increase in cell number indicating that our strains were responsible for the degradation.