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Browsing by Author "Amund, Olukayode O."

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Acenaphthene biodegradation and structural and functional metagenomics of the microbial community of an acenaphthene-enriched animal charcoal polluted soil
(Biocatalysis and Agricultural Biotechnology, 2021-02) Salam, Lateef B.; Obayori, Oluwafemi S.; Ilori, Mathew O.; Amund, Olukayode O.
Animal charcoal from skin and hides cottage industries indiscriminately disposed in run offs and drainage channels harbors hazardous constituents that are mutagenic and toxic, and thus require bio-based ecofriendly depuration strategies. A microbial consortium (FN7) from an animal charcoal polluted site enriched with acenaphthene was structurally and functionally characterized via illumina next generation sequencing and annotation of their putative ORFs, and also studied for ability to degrade acenaphthene. Structurally, FN7 metagenome consists of 7 phyla, 13 classes, 38 orders, 49 families, 67 genera, 68 species, and 45 strains, respectively. The dominant phylum, class, order, family, genus, species, and strain in the metagenome are Proteobacteria (48.9%), Actinobacteria (31.8%), Actinomycetales (28.0%), Enterobacteriaceae (18.9%), Paracoccus (12.9%), Bacillus cereus group (13.5%), and Methylobacterium radiotolerans JCM 2831 (22.4%). The microbial consortium in the metagenome degraded 59.68% (29.84 mg l−1) and 89.16% (44.58 mg l−1) of the initial concentration of acenaphthene (50 mg l−1) in 14 and 21 days. Functional annotation of the putative ORFs of the metagenome using KEGG KofamKOALA, NCBI's conserved domain database, BacMet, and Antibiotic Resistance Gene-ANNOTation (ARG-ANNOT) revealed the detection of hydrocarbon-degradation genes including salicylaldehyde dehydrogenase and catechol 1,2 dioxygenase involved in acenaphthene degradation, resistance genes for mercury, arsenic, cadmium, nickel, and several others, and antibiotic resistance genes for 15 antibiotic classes such as β-lactam, colistin, aminoglycoside, among others. This study revealed that members of FN7 metagenome are equipped with requisite gene batteries and could be veritable bioresources for in vitro biodegradation as well as on-site bioremediation of animal charcoal polluted sites.
Aerobic Degradation of Di- and Trichlorobenzenes by Two Bacteria isolated from Polluted Tropical Soils.
(Pergamon, 2007-01-01) Adebusoye, Sunday A.; Picardal, Flynn W.; Ilori, Matthew O.; Amund, Olukayode O.; Fuqua, Clay; Grindle, Nathan
Two polychlorinated biphenyl (PCBs)-degrading bacteria were isolated by traditional enrichment technique from electrical transformer fluid (Askarel)-contaminated soils in Lagos, Nigeria. They were classified and identified as Enterobacter sp. SA-2 and Pseudomonas sp. SA-6 on the basis of 16S rRNA gene analysis, in addition to standard cultural and biochemical techniques. The strains were able to grow extensively on dichloro- and trichlorobenzenes. Although they failed to grow on tetrachlorobenzenes, monochloro- and dichlorobenzoic acids, they were able to utilize all monochlorobiphenyls, and some dichlorobiphenyls as sole sources of carbon and energy. The effect of incubation with axenic cultures on the degradation of 0.9 mM 1,4-dichlorobenzene, 0.44 mM 1,2,3- and 0.43 mM 1,3,5-trichlorobenzene in mineral salts medium was studied. Approximately, 80–90% of these xenobiotics were degraded in 200 h, concomitant with cell increase of up to three orders of magnitude, while generation times ranged significantly (P < 0.05) from 17–32 h. Catechol 1,2-dioxygenase and catechol 2,3-dioxygenase activities were detected in crude cell-free extracts of cultures pre-grown with benzoate, with the latter enzyme exhibiting a slightly higher activity (0.15–0.17 lmol min1 mg of protein1) with catechol, suggesting that the meta-cleavage pathway is the most readily available catabolic route in the SA strains. The wider substrate specificity of these tropical isolates may help in assessing natural detoxification processes and in designing bioremediation and bioaugmentation methods.
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.
Alkaline extracted cyanide from cassava wastewater and its sole induction of chromosomal aberrations on Allium cepa L. root tips
(Taylor and Francis Online : Environmental Technology, 2021-04) Ogunyemi, Adewale; Abayomi, Akeem A.; Opawale, Rachael O.; Samuel, Titilola A.; Ilori, Matthew O.; Amund, Olukayode O.; Babajide, Alo
Cassava, a staple crop in Nigeria, processed by numerous factories in rural and sub-urban locations is known to contain some level of cyano compounds. Lack of stringent environmental regulations on management of cassava wastewater (CWW) from cassava processing factories had led to its indiscriminate discharge on the environment. CWW samples were obtained from cassava processing factories from selected states (Lagos (A), Oyo (B), Ogun 1 (C1), Ogun 2 (C2) and Cross River (D)) in Nigeria to determine the cytotoxic and genotoxic effects of extracted cyanide from the wastewaters. The cyanide was hydrolyzed via chemical degradation utilizing 1.25 M NaOH and subsequently titrated using silver nitrate with p-dimethylaminobenzalrhodamine as indicator. Further, in order to explore the potential toxicity of this pollutant present in the effluent, a battery of short-term biological assay (Allium cepa chromosomal aberration test) was used. Bulbs with roots of Allium cepa L. were treated with different concentrations (0.05%, 0.1%, 0.2%, 0.4%, and 0.8%) of CWW, and after 48 h the root tips were processed for cytological studies by the aceto-orcein squash procedure. The results revealed that cyanide concentrations on re-fluxing were in the range of 1.0 mg/L and 1.3 mg/L. All concentrations induced a number of chromosomal aberrations in the root tip cells. The mitotic index decreased significantly (p < 0.05) with increasing concentration. The cytotoxic effects showed strong concentration dependent root growth inhibition with EC50 values of 30, 20, 37, 43 and 22 % for A, B, C1, C2 and D, after 72 h. The findings thus indicate that alkali treatment is very efficient in degrading the cyanide content of CWW and has shown that the combination of physico-chemical analysis along with the sole toxicity assessment could provide valuable information about the sole toxicity of cyanide as a chemical pollutant present in the cassava effluent.
Assessment of bacterial degradation of lignocellulosic residues (sawdust) in a tropical estuarine microcosm using improvised floating raft equipment
(Elsevier, 2015-10-01) Buraimoh, Olanike M.; Ilori, Matthew O.; Amund, Olukayode O.; Michel Jr, Frederick C.; Grewal, Sukhbir K.
In situ and laboratory studies were carried out to determine the ability of bacterial strains isolated from a tropical lagoon to degrade lignin and carbohydrate components of sawdust, with a view to abating the impact of sawdust pollution on these ecosystem. A floating raft system was designed and fabricated to carry out the in situ biodegradation studies over a period of 24 weeks. Nine bacterial strains identified by 16S rRNA gene sequencing as species of Streptomyces, Bacillus and Paenibacillus isolated from the lagoon were used as seed organisms. In the in situ study, 59.2% of sawdust was depleted at the rate of 1.175 x 10-4 gd-1 cm-3 by the bacterial isolates, whereas the lignin component of the sawdust decreased by up to 82.5% at the rate of 1.80 x 10-5 gd-1 cm-3. The maximum decrease in carbohydrate content was 85% at the rate of 2.192 x 10-7 gd-1 cm-3. In a similar experiment under laboratory conditions, total weight losses ranging from 26 to 51% in the wood residues were observed.
Bacteria with dual resistance to elevated concentrations of heavy metals and antibiotics in Nigerian Contaminated Systems.
(Springer Netherlands, 2010-09-01) Oyetibo, Ganiyu O.; Ilori, Matthew O.; Adebusoye, Sunday A.; Obayori, Oluwafemi S.; Amund, Olukayode O.
Samples of soil, water, and sediments from industrial estates in Lagos were collected and analyzed for heavy metals and physicochemical composition. Bacteria that are resistant to elevated concentrations of metals (Cd2+, Co2+, Ni2+, Cr6+, and Hg2+) were isolated from the samples, and they were further screened for antibiotic sensitivity. The minimum tolerance concentrations (MTCs) of the isolates with dual resistance to the metals were determined. The physicochemistry of all the samples indicated were heavily polluted. Twenty-two of the 270 bacterial strains isolated showed dual resistances to antibiotics and heavy metals. The MTCs of isolates to the metals were 14 mM for Cd2+, 15 mM for Co2+ and Ni2+, 17 mM for Cr6+, and 10 mM for Hg2+. Five strains (Pseudomonas aeruginosa, Actinomyces turicensis, Acinetobacter junni, Nocardia sp., and Micrococcus sp.) resisted all the 18 antibiotics tested. Whereas Rhodococcus sp. and Micrococcus sp. resisted 15 mM Ni2+, P. aeruginosa resisted 10 mM Co2+. To our knowledge, there has not been any report of bacterial strains resisting such high doses of metals coupled with wide range of antibiotics. Therefore, dual expressions of antibiotics and heavy-metal resistance make the isolates, potential seeds for decommissioning of sites polluted with industrial effluents rich in heavy metals, since the bacteria will be able to withstand in situ antibiosis that may prevail in such ecosystems.
The bio-corrosive nature of injection water sources used in the Nigerian oil and gas industry.
(National Institute of Ecology, 2013) Okoro, Chuma C.; Amund, Olukayode O.; Samuel, O. B.
The bio-corrosive nature of injection water used in the Nigerian oil and gas industry from different sources such as seawater, produced water, brackish water, fresh and underground water were investigated with special emphasis on some of their components which enhance corrosion such as microbial activity, dissolved oxygen and presence of dissolved substances such as chlorides, sulfates and ammonia. Our investigation reveals that seawater, produced water and brackish water had higher salinity, conductivity, concentrations of dissolved oxygen, TDS, sulfate, organic nutrients, sulphate reducing bacteria (SRB), acid producing bacteria (APB) and higher corrosion rates (0.24-0.56 mm yr-1) than fresh and underground water whose corrosion rates ranged between 0.06-0.08 mm yr-1. Our study also established high correlation between corrosion rates and the concentrations of Fe2+, SRB, APB, TDS, DO and conductivity in all injection water samples examined in the study. The role of microorganisms in enhancing corrosion was also clearly established in some samples.
Biodegradation of crude oil and phenanthrene by heavy metal resistant Bacillus subtilis isolated from a multi-polluted industrial wastewater creek
(Elsevier, 2017-05-01) Oyetibo, Ganiyu O.; Chien, Mei-Fang; Ikeda-Ohtsubo, Wakako; Suzuki, Hitoshi; Obayori, Oluwafemi S.; Adebusoye, Sunday A.; Ilori, Matthew O.; Amund, Olukayode O.; Endo, Ginro
A critical bottleneck associated with bioremediation technology in multi-polluted environments is microbiostasis due to metal toxicity. Autochthonous Bacillus species that would harness a repertory of traits to catabolize hydrocarbons and simultaneously sequester heavy metals (HMs) is invaluable in the environment contaminated with divergent pollutants. Fourteen HM-resistant bacilli from polluted creek were characterized using phenotypic and molecular criteria, and studied for hydrocarbon degradation in chemically defined media amended with Co2+ and Ni2+ (5.0 mmol l−1 each). Phylogenetic analyses revealed distribution of the bacilli into three clades. Two dissimilar strains of Bacillus subtilis (M16K, and M19F) with 19.1% sequence divergence, exhibited excellent degradation of crude oil (>94.0%) with evidence of early degradation of isoprenoid hydrocarbons and concurrent metal removal 18 d post-inoculation. Similarly, phenanthrene degradation (>85.0%), and corresponding metal detoxification occurred in 28 d axenic culture of the strains. Strain M16K and M19F were metabolically active in matrices containing HMs, degraded hydrocarbons and simultaneously removed HMs from the medium. To the best of our knowledge, this is the first report of metal-resistant Bacillus subtilis strains showing simultaneous degradation of hydrocarbons and detoxification of metals, particularly in the Sub-Saharan Africa. The bacilli could be useful as potential biological agents in effective bioremediation campaign for multi-polluted environments.
Biodegradation of Hydrocarbons in Untreated Produced Water using Pure and Mixed Microbial Cultures
(2002) Okoro, C. C.; Amund, Olukayode O.
Biodegradation studies of hydrocarbons in untreated produced water from Escravos tank farm were undertaken over a period of time using Pure and Mixed microbial cultures and the produced water as the sole carbon and energy source. Gas chromatographic analysis showed that untreated produced water with an oil and grease content of 1407 mg/1 contained various petroleum hydrocarbon fractions including n-alkanes (608mg/1), NSO compounds (12.68mg/1) and PAHs (0.833mg/l). Upon mechanical treatment, the oil and grease content of produced water was reduced to 44mg/l while n-alkanes, aromatics, NSO compounds and PAHs were reduced to 38.4, 2.65, 1.78, 0.0655 mg/l respectively. An Achromobacter sp., used in pure culture and without nutrient supplementation reduced the oil and grease content to 18 mg/l while n-alkanes, aromatics, NSO compounds and PAHs were reduced to 13.68, 1.32, 1.20, and 0.0056 mg/l respectively after 40 days of exposure and this result was better than when mixed microbial culture were used. This is an indication that produced water hydrocarbons are readily biodegradable and pure bacterial cultures can be very effective in degrading its petroleum hydrocarbons.
Biodegradation of p-Chloroaniline by Bacteria Isolated from Contaminated Sites
(2010) Fashola, M. O.; Obayori, O. S.; Omotayo, A. E.; Adebusoye, S. A.; Amund, Olukayode O.
Enrichment of water from a contaminated site in a textile industry in Ikeja resulted in the isolation of two bacteria belonging to the genera Alcaligenes and Cellulomonas. These bacteria were able to mineralize para-chloroaniline (p-chloroaniline). Time course degradation of p-chloroaniline using pure cultures of these organisms showed that p-chloroaniline supported the growth of these isolates. An initial increase in cell densities of 7.50-9.46 cfu/mL was recorded from day 0-9th day for Cellulomonas sp. while for Alcaligenes denitrificans it was 7.20-9.40 cfu/mL. After day 9, a decrease in population occurred, indicating non-availability of nutrients or toxicity of the medium. Simultaneously, a decrease in the pH, indicative of increased acidity of the medium, was also observed from the first day. The result of the GC analysis of the pure isolates on p-chloroaniline shows that 86.5% of the p-chloroaniline was degraded by the Cellulomonas sp. while 81.2% was degraded by the A. denitrificans in 30 days. These bacterial isolates utilized other hydrocarbons such as pyrene, anthracene, crude oil and chlorobenzoates as sole source of carbon and energy but not phenanthrene, naphthalene and biphenyl. The two isolates tolerated NaCl concentration of up to 5%.
Biodegradation of petroleum hydrocarbons in the presence of nickel and cobalt
(Journal of basic microbiology, 2013-11) Oyetibo, Ganiyu O.; Ilori, Matthew O.; Obayori, Oluwafemi S.; Amund, Olukayode O.
Bioremediation of environments co-contaminated with hydrocarbons and heavy metals often pose a challenge as heavy metals exert toxicity to existing communities of hydrocarbon degraders. Multi-resistant bacterial strains were studied for ability to degrade hydrocarbons in chemically defined media amended with 5.0 mM Ni2þ, and Co2þ. The bacteria, Pseudomonas aeruginosa CA207Ni, Burkholderia cepacia AL96Co, and Corynebacterium kutscheri FL108Hg, utilized crude oil and anthracene without lag phase at specific growth rate spanning 0.3848–0.8259 per day. The bacterial populations grew in hydrocarbon media amended with nickel (Ni) and cobalt (Co) at 0.8393–1.801 days generation time (period of exponential growth, t ¼ 15 days). The bacteria degraded 96.24–98.97, and 92.94–96.24% of crude oil, and anthracene, respectively, within 30 days without any impedance due to metal toxicity (at 5.0 mM). Rather, there was reduction of Ni and Co concentrations in the axenic culture 30 days post-inoculation to 0.08–0.12 and 0.11– 0.15 mM, respectively. The metabolic functions of the bacteria are active in the presence of toxic metals (Ni and Co) while utilizing petroleum hydrocarbons for increase in biomass. These findings are useful to other baseline studies on decommissioning of sites co-contaminated with hydrocarbons and toxic metals.
Biodegradation of Petroleum Hydrocarbons Under Tropical Estuarine Conditions
(Kluwer Academic Publishers, 1990-09) Amund, Olukayode O.; Igiri, C. O.
The physic-chemical parameters of water samples collected from three points in the Lagos lagoon were studied for 12 months. Salinity varied seasonally but the temperature, pH, dissolved O2, conductivity, NO3 and HPO42- concentrations were relatively constant. There was a direct proportionality between the population density of hydrocarbon-utilizing bacteria and the oil content of water samples. Twelve hydrocarbon-utilizing bacteria were isolated by selective enrichment and characterized as species of Pseudomonas, Alcaligenes, Acinetobacter and Bacillus. The organisms grew mainly on long-chain aliphatic hydrocarbons. Laboratory and field biodegradation studies showed both quantitative and qualitative changes in the hydrocarbon content of crude oil due to microbial degradative activities and a faster rate of oil depletion from the Lagos lagoon during the rainy season. The results obtained could offer a predictive model for estimating the rate of disappearance of petroleum hydrocarbons from the tropical estuarine environment.
Biodegradation of Polycyclic Aromatic Hydrocarbon Mixtures by Rhodococcus Pyridinivorans FF2 and Pseudomonas Aeruginosa F4b Isolated from Sediments of Lagos Lagoon, Nigeria
(Open Access Journal Biogeneric Science and Research, 2020-07-07) Obi, Chioma C.; Adebusoye, Sunday A.; Amund, Olukayode O.; Ugoji, Esther E.; Hickey, William J.
Polycyclic aromatic hydrocarbons (PAH) are widespread environmental pollutants that need urgent attention because of their toxicity. Development of microbial inoculants for PAH bioremediation is a potential avenue by which the environmental hazards posed by PAH can be addressed. The goal of the study was to determine if using PAH mixtures, rather than single PAH, as enrichment substrates would yield isolates that have superior PAH degradation abilities and/or are retrieve novel taxa from the PAH-contaminated sediments of Lagos Lagoon, Nigeria. The use of a quaternary mixture of PAH (pyrene, fluoranthene, fluorene, benz[a ]anthracene) was successful in yielding two isolates, Pseudomanas aeruginosa strain F4b and Rhodococcus pyridinivorans strain FF2 with capabilities to grow on multiple PAH, and thus potentially useful in bioremediation. In addition to the PAH degraded both isolates could grow on a wide range of other hydrocarbon substrates. The isolates of P. aeruginosa and R. pyridinivorans were identified as possessing PAH ringhydroxylating dioxygenases of the nahAC and narAa genotypes, respectively. The present study extends our knowledge of PAH biodegradation by P. aeruginosa and is the first report of PAH biodegradation by R. pyridinivorans. The capability of the R. pyridinivorans isolate to effectively degrade a highly toxic PAH, benz[a]anthracene, has particular importance for use in bioremediation.
Biodegradation of Produce Water Hydrocarbons by Pure Cultures of Alcaligenes sp.
(2010-12-15) Okoro, Chuma C.; Amund, Olukayode O.
Biodegradation studies of hydrocarbons in untreated produce water from an oil production facility in Nigeria was undertaken over a period of time using pure cultures of Alkaligenes sp. Isolated from Escravos River where produce water was being discharged as at the time the studies were carried out. Gas chromatography and mass spectrometry were used to monitor the rate of reduction in some petroleum hydrocarbon fractions while the index used to evaluate biodegradation was the decreasing trend in the ratios of nC17/Pristane and nC18/Phytane. Gas chromatographic analysis showed that untreated produced water used for the study had an oil and grease content of 1407mg/L, this includes n-alkanes (608mg/L), Aromatics (13.88mg/L), NSO compounds (12.68mg/L) PAHs(0.833mg/L) and some unidentified greasy components. Upon mechanical treatment, the oil and grease component of produce water was reduced to 44mg/L comprising of n-alkanes (38.40mg/L), Aromatics (2.65mg/L), NSO compounds (1.78mg/L), PAHs (0.0655mg/L) and some unidentified greasy component. A pure culture of Alcaligenes sp. after 40 days of exposure to untreated produced water reduced the oil and grease content to 19.58mg/l comprising of n-Alkanes (16.87mg/l), Total aromatics (1.25mg/l), NSO compounds (0.98mg/l) and PAH (0.0096mg/l). This result indicate that produce water is readily biodegradable and pure cultures of Alcaligenes sp. used for the study were very efficient in the degradation of produced water hydrocarbons especially the recalcitrant PAH component when compared with the conventional mechanical treatment process. [Journal of American Science 2010;6(4):107-113]. (ISSN: 1545-1003).
Biodegradation of produced water hydrocarbons by Aspergillus fumigatus
(American Journal of science, 2010) Okoro, Chuma C.; Amund, Olukayode O.
Biodegradation studies of hydrocarbons in untreated produce water from an oil production facility in Nigeria were undertaken over a period of time using pure cultures of Aspergillus fumigatus isolated from the zone of produce water discharge into the receiving sea water. The rate of reduction in some petroleum hydrocarbon fractions such as n-Alkanes, Aromatics, Nitrogen Sulfur and Oxygen (NSO) containing compounds and Polycyclic aromatic hydrocarbons (PAHs) were monitored by means of Gas chromatography and Mass spectrometry using mechanically treated produced water as a reference. Gas chromatographic analysis showed that untreated produced water used in the study had an oil and grease content of 1407mg/l, this includes n-alkanes(608mg/l), Aromatics (13.88mg/l), NSO compounds (12.68mg/l) PAHs(0.833mg/l) and some unidentified greasy components. Upon mechanical treatment, the oil and grease component of produced water was reduced to 44mg/l comprising of nalkanes (38.40mg/), Aromatics (2.65mg/), NSO compounds(1.78mg/), PAHs (0.0655mg/) and some unidentified greasy component. A pure culture of Aspergillus fumigatus after 120 days of exposure to untreated produce water was able to reduce the hydrocarbons to the following components. n-Alkanes (78.5mg/l), Aromatics(1.58mg/l), NSO compounds (1.22mg/l) and PAHs (0.0168 mg/l). This result indicate that produce water from Chevron’s Escravos tank farm is readily biodegradable and the Aspergillus fumigatus culture used in the study was very effective in degrading the PAHs and NSO components of the hydrocarbon when compared with the conventional mechanical treatment process even though the biodegradation process was very slow.
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
Biodegradation Potential of Two Rhodococcus Strains Capable of Utilizing Aniline as Carbon Source in a Tropical Ecosystem.
(Academic Journals Inc., 2008) Nwinyi, Obina C.; Nwodo-Chinedu, S.; Amund, Olukayode O.
Two closely related strains of Rhodococcus species, isolated from aniline polluted tropical ecosystem, were able to utilize aniline as carbon source in 3.0 and 4.0 mM concentrations at 30°C and pH of about 6.4. Rapid increase in turbidity and a sharp decline in pH were observed in the cultures of both organisms within 24 h of incubation. Shortly after the period, growth became slower. Turbidity values obtained at 4.0 mM concentrations of aniline was about twice the values obtained at 3.0 mM concentrations. Aniline concentrations of 10 mM and above were found to be toxic for the organisms. Rhodococcus species because of its significant prevalence in agricultural soils can be used as an effective means of recovering tropical agricultural land polluted with aniline, aniline-based herbicides or its derivatives.
Biodegradation potentials of polyaromatic hydrocarbon (pyrene and phenanthrene) by Proteus mirabilis isolated from an animal charcoal polluted site
(Elsevier, 2017-10-01) Obayori, Oluwafemi S.; Salam, Lateef B.; Oyetibo, Ganiyu O.; Idowu, Monsurat; Amund, Olukayode O.
Indiscriminate disposal of animal charcoal from skin and hides cottage industries often impact the environments with toxic hydrocarbon components and thus require eco-friendly remedial strategies. A bacterial strain isolated from a site polluted with animal charcoal was characterized, identified as Proteus mirabilis 10c, and studied for ability to degrade pyrene and phenanthrene. The bacterium resisted 30 µg chloramphenicol, 10 µg ampicillin, 30 µg amoxicillin and 10 µg perfloxacin; while it utilized a number of polycyclic aromatic hydrocarbons and cinnamic acid. Specific growth rate on pyrene and phenanthrene were 0.281 d−1 and 0.276 d−1, respectively. Kinetics of degradation of pyrene was 87.92 mg l−1 in 30 days at the rate of 2.93 mg l−1 d−1, biodegradation constant at 0.073 d−1 and half-life of 9.50 d. The corresponding values for phenanthrene degradation kinetics by the bacterium were 90.12 mg l−1, 3.02 mg l−1 d−1, 0.079 d−1 and 8.77 d, respectively. Efficient degradation of crude oil (92.3%) in chemically defined medium was evident with near-disappearance of most aromatic spectra in 30 days. Considering its unique physiologies and broad specificities for aromatic and aliphatic hydrocarbons, the bacterium has potentials for decommissioning environments contaminated with toxic components of animal charcoal.
Biologically Active Solid Deposits in Biocide treated Oil and Gas pipelines from a Nigerian Onshore Oil Production Facility
(National Institute of Ecology, 2013) Okoro, C. C.; Amund, Olukayode O.; Samuel, O. B.
Pipelines transporting crude oil, produced water and gas from an onshore oil producing facility in Nigeria are subject to frequent corrosion failures despite treatment programs with chlorine (0.5mg L-1) and sodium azide (0.2 mg L-1). Solid deposit samples from 6 corroded pipelines were analyzed chemically and biologically to determine whether the corrosion episodes were as a result of microbial activity. Microbiological analysis showed relatively high concentrations of microorganisms associated with corrosion such as SRBs (103-105 cell g-1) and APBs (103-107 cells g-1) while chemical analysis showed evidence of corrosion products such as iron II, calcium, sulfide, carbonate and bicarbonate. Chemical analysis also revealed that environmental conditions such as availability of nutrients, pH, moisture and redox potential were favorable for the growth and proliferation of these microorganisms. All the pipeline samples that were investigated recorded remarkable corrosion rates that ranged from 0.065-0.30 mm yr-1 but the rates were higher in chloride treated pipelines. Our investigation revealed that the solid deposit samples were biologically active and pipeline corrosion was as a result of microbial activity. Thus the prevalence of bio-corrosion is likely to be higher in cases where routine pipeline cleaning and checks are not strictly adhered to despite regular biocide treatment programs
Biotechnological remedies for the estuarine environment polluted with heavy metals and persistent organic pollutants
(Elsevier, 2017-04-01) Oyetibo, Ganiyu O.; Miyauchi, Keisuke; Huang, Yi; Chien, Mei-Fang; Ilori, Matthew O.; Amund, Olukayode O.; Endo, Ginro
Estuaries in the areas prone to anthropogenic activities are exposed to multifarious pollutants. Toxic concentrations of heavy metals do exist with persistent organic compounds in such estuaries prolonging the recalcitrance and ecotoxicological consequences of the chemicals, which impact on the health of the brackish water and by extension, the oceans. The quest for high aesthetic quality of the estuarine environment is gaining attention from global campaign, which requires effective remedial strategies to replace the physical and chemical methods in use that are costly and often leave behind toxic residues in the environment. Contrary to physico-chemical remedial processes, bioremediation strategies are projected as a promising green technology to remove pollutants from the estuarine environment. The concept of bioremediation involves the use of competent biological elements such as microorganisms and plants, along with or without the biomolecules they produced, to ameliorate pollution. Therefore, this paper reviews the various bioremediation technologies that would be applicable to decommissioning estuarine environments polluted with toxic metals and persistent organic compounds.