Department Of Microbiology
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The first phase in the development of the University began with the establishment of the Faculty of Science in October 1964. In October 1967, the Faculty was split into two schools i.e., the School of Biological Sciences, and the School of Mathematical and Physical Sciences.
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- ItemOpen AccessAerobic Degradation of Di- and Trichlorobenzenes by Two Bacteria isolated from Polluted Tropical Soils.(2007) Adebusoye, S.A; Picardal, F.W; Ilori, M.O; Amund, O.O; Fuqua, C; Grindle, NTwo 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.
- ItemOpen AccessAerobic Degradation of Naphthalene, Fluoranthene, Pyrene and Chrysene using Indigenous Strains of Bacteria Isolated from a former Industrial Site(SENRA Academic Publishers, British Columbia, 2013-06) Nwinyi, O.C; Picardal, F.W; An, T.T; Amund, O.OFour 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.
- ItemOpen AccessAerobic Degradation of Naphthalene, Fluoranthene, Pyrene and Chrysene Using Indigenous Strains of Bacteria Isolated from a former Industrial Site(SENRA Academic Publishers, 2013-06) Nwinyi, Picardal; AmundFour 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.
- ItemOpen AccessAntibacterial Effect of Edible Plant Extract on Escherichia coli 0157:H7(Pakistan Journal of Nutrition, Asian Network for Scientific Information, 2006-01-01) Aboaba, O.O.; Smith, S. I.; Olude, F. O.Sixteen preparation of the ethanol and aqueous extracts of four edible plants, Entada africana (bark),Terminalia avicennoides (bark),Mitragyna stipulosa (bark) Lannae acida (stem bark) were screened for their inhibitory effects on ten strains of E coli 0157:H7 (EHEC) using the agar diffusion method. It was shown that ethanol extracts of Entanda africana inhibited all the ten strains used, some extracts showed variable antibacterial activities while some others could not cause any inhibition. The minimum inhibitory concentration (MIC) of the potent extracts ranged from 1.56mg/ml to 50.00mg/ml while the minimum bacteriocidal concentration (MBC) was between 6.25mg/ml to 25.00mg/ml. Pytochemical screening of the extracts revealed that all contained saponin. Some showed presence of tannins and glycosides while alkaloid was not detected in all samples.
- ItemOpen AccessAntibiotic resistant profiles of food (fresh raw milk) and environmental (abattoir effluents) isolates of Listeria monocytogenes from the six zones of Nigeria(African Journal of Microbiology Research, 2013-08-06) Enurah, L. U.; Aboaba, O. O.; Nwachukwu, S.C.U.; Nwosuh, C. I.The prevalence of Listeria monocytogenes in fresh raw milk and abattoir effluents in the six zones of Nigeria was determined. Antibiotic resistant profile of the isolates was examined using the Bauer- Kirby disc diffusion assay. A total of 626 food and environmental samples were cultured on selective media out of which 54 (8.6%) were positive for L. monocytogenes. Chloramphenicol was the most effective antibiotic against the isolates with the least resistance (3.70%) while nalidixic acid proved to be least effective with resistance of 90.74%. The multiple-antibiotic resistant pattern of the isolates showed nalidixic acid/cloxacillin (35.2%), nalidixic acid/colistin (31.5%) and cloxacillin/colistin/nalidixic acid (29.6%) to be most prominent. The least value was observed in chloramphenicol/nitrofurantin/cotrimoxazole with 5.6%. The modal values of the minimum inhibitory concentrations (MICs) of the antibiotics to the isolates range between 4.0 and >16.0 μg/ml. Chloramphenicol, nitrofurantin and gentamycin recorded the highest MIC compared with other antibiotics. This study has demonstrated that a wide and rapidly expanding range of undesirable and, in some cases, multi-resistant determinants is currently present in L. monocytogenes
- ItemOpen AccessAntimicrobial activities of some Nigerian spices on some pathogens(AGRICULTURE AND BIOLOGY JOURNAL OF NORTH AMERICA, 2011-01-01) Aboaba, O. O.; Ezeh, A. R.; Anabuike, C. L.The aqueous and ethanol extracts of four spices ( Monodora myristica, Piper guineense, Xylopia aethiopica, Tetrapleura tetraptera ) were prepared and the antibacterial properties assessed using the agar diffusion method. The test organisms were Enterohaemorrhagic E.coli, Shigella, Salmonella, Klebsiella, Pseudomonas, Klebsiella pnemonium, Staphylococcus aureus, Staphylococcus aureus (ATCC 25923), Bacillus sp. and Enterococcus faecalis. The susceptibility of the test bacteria strains to various antibiotics was performed. The aqueous extracts had antimicrobial activities on all test organisms used (MIC values of 30-60mg/ml and a range of inhibition, 10-25mm). The ethanol extracts were less sensitive (3.3-26mg/ml on E. feacalis). The phytochemical screening of the potent extracts revealed the presence of terpenoids, flavonoid and glycosides. The test organisms showed susceptibility to majority of the antibiotics used ranging from an average of 10mm-37mm. The aqueous extracts can be used as an alternative therapy to the use of antibiotics as the zones of inhibition exhibited by the test strains to both were comparable.
- ItemOpen AccessAntimicrobial Activity Of Orange Oil On Selected Pathogens.(2013) Obidi, O. F.; Adelowotan, A. O.; Ayoola, G. A; Johnson, O. O.; Hassan, M. O.; Nwachukwu, S. C. U.ABSTRACT The antimicrobial activity of orange oil extracted by steam distillation from peels of orange fruits (Citrus sinensis) was screened against some medically important microorganisms. Gram-positive bacteria (Staphyloccocus aureus 001, S. aureus ATCC 25923, Enteroccocus feacalis 002, E. feacalis ATCC 295212); Gram- negative bacteria (Pseudomonas aeruginosa 003, Escherichia. Coli 004, E. coli ATCC 29522) and fungi (Candida albicans 010, C. albicans ATCC 90028) were used. The minimum inhibitory concentration (MIC) of orange oil was estimated using disc diffusion method at concentrations ranging from (1.65-422 mg/ml). Orange oil exhibited inhibitory effects against all the organisms. The MICs observed for the isolates were: S. aureus 001 (1.65 mg/ml), S. aureus ATCC 25923 (0.69 mg/ml), Enterococcus feacalis 002 (0.09 mg/ml), E. feacalis ATCC 295212 (0.05 mg/ml), P. aeruginosa 003 (1.85 mg/ml), E. coli 004 (1.37 mg/ml), E. coli ATCC 29522 (0.82 mg/ml), C. albicans 010 (0.02 mg/ml), C. albicans ATCC 90028 (0.01 mg/ml). The GC-MS revealed that orange oil contained mainly cyclohexane, 1-methylene-4-(1-methylethenyl; bicyclo [4.1.0] hept--ene3,7,7 -trimethyl; D-limonene; 1, 6-octadien-3-ol, 3,7-dimethy-l,2-aminobenzoate; 3-cyclohexen-1-ol, 4-methyl-1-(1-methylethyl); 2-cyclohexen-1-ol, 2-methyl-5-(1methylethenyl); 2-methoxy-4-vinylphenol; 3-furanacetic acid, 4-hexyl-2,5-dihydro -2,5-dioxo; naphthalene, 1,2,3,5,6, 8a-hexahydro-4,7-dimethyl-1-(1-methylethyl) -, (1S-cis) and n-hexadecanoic acid. The result indicated that orange oils have antimicrobial properties and may be applied in local therapies in the treatment of diseases caused by the microorganisms tested. Further research is needed to achieve appropriate formulation.
- ItemOpen AccessAntimicrobial Susceptibilities of Salmonellae Isolated from Food Handlers and Cattle in Lagos, Nigeria(2009-03-09) Smith, S. I.; Bamidele, M.; Goodluck, H. A.; Fowora, M. N.; Omonigbehin, E. A.; Opere, B. O.; Aboaba, O. O.Purpose: Food handlers play an important role in the transmission of typhoid bacilli and other Salmonella spp. This study was conducted to determine the prevalence and antimicrobial resistance patterns of Salmonella spp. from food handlers and cattle and compare the patterns with specimens from patients. Methods: A total of 206 stool samples from apparently healthy food handlers from bukkas (cafeteria) and 100 stool samples from cattle were collected in Lagos Metropolis between June 2006 and June 2007. The prevalence and susceptibility patterns of the S. typhi isolates from the samples and those obtained from the stool samples of 27 patients were determined. Results: Salmonella species isolated from the stool samples collected from food handlers were S. typhi, S. enteritidis, S. choleraesuis, S. paratyphi A and S. arizona with prevalence of 6.8%, 5.3%, 2.9%, 1.5% and 0.5%, respectively. S. enteritidis and S. typhimurium were isolated from 100 faecal cattle samples with prevalence of 12% and 3%, respectively. Nearly all the isolates (including the clinical isolates) were sensitive to nitrofurantoin, nalidixic acid, and ofloxacin, while all were sensitive to ciprofloxacin. Conclusion: Food handlers working in bukkas (cafeteria) and cattle are possible reservoirs of Salmonalle species in Lagos. Other than fluoroquinolones, Salmonalle species exhibit high levels of resistance to most antibiotics.
- ItemOpen AccessApplication of Candida valida as a protein supplement(Journal of Food Safety, 2010-03-28) Kuforiji, O. O.; Aboaba, O. O.An investigation was carried out on the carbon and nitrogen sources needed for the growth of a yeast, Candida valida (syn. Candida mycoderma), isolated from Ogi, a fermented edible corn product given to babies at weaning. The suitability of this organism as a protein supplement in foods was also determined. The yeast was grown in different carbon sources: glucose, fructose, lactose, maltose, starch, dextrin, mannitol and ethanol, and in different nitrogen sources like urea, amino acids, ammonium nitrate, sodium nitrate and ammonium sulfate, as part of the synthetic basal medium for 7 days and the growth measured using the dry weight method. A significantly high increase in yield was observed when 1% fructose was used and maximum yield was obtained with 3.5 and 0.2% (w/v) of fructose and urea as carbon and nitrogen sources, respectively. Growing the fungus in 0.3% cane molasses, a natural substrate gave a significantly higher increase in yield than in a synthetic medium. As a food supplement, other nutrient contents of this organism such as ash, crude fiber, lipids and carbohydrates were also analyzed in addition to the protein, free amino acids and energy values
- ItemOpen AccessAssessment of bacterial degradation of lignocellulosic residues (sawdust) in a tropical estuarine microcosm using improvised floating raft equipment(2015) Buraimoh, O.M; Ilori, M.O; Amund, O.O; Michel Jr., F.C; Grewal, S. KIn 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.
- ItemOpen AccessAssessment of bacterial degradation of lignocellulosic residues (sawdust) in a tropical estuarine microcosm using improvised floating raft equipment(Elsevier, 2015) Buraimoh, O.M; Ilori, M.O; Amund, O.O; Michel Jr., F.C; Grewal, S.KIn 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.
- ItemOpen AccessAssessment of bacterial degradation of lignocellulosic residues (sawdust) in a tropical estuarine microcosm using improvised floating raft equipment(Elsevier, 2015) Buraimoh, O.M; Ilori, M.O; Amund, O.O; Michel, F.C; Grewa, S.KIn 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 × 10−4 g d−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 × 10−5 g d−1 cm−3. The maximum decrease in carbohydrate content was 85% at the rate of 2.192 × 10−7 g d−1 cm−3. In a similar experiment under laboratory conditions, total weight losses ranging from 26 to 51% in the wood residues were observed
- ItemOpen AccessBacillus sphaericus a case study for antibacterial and photocatalytic effect of titanium nanoparticles and microcrystalline TIO2 on gram-positive paint microbes.(Journal of Industrial Research and Technology, 2016) Obidi, O.F.Currently, there is a massive drift in bacteria as a result of emergence of resistant strains to conventional paint biocides. This study focused on a photodestructive strategy of paint microorganisms using titanium dioxide nanoparticles. The comparative toxicity of microcrystalline TiO2 and TiO2 Nanoparticles (NPs) on Bacillus sphaericus, a spore forming and environmentally diverse microbe isolated from spoilt paints was investigated. The antibacterial performance of the TiO2 NPs with 38nm particle size in the inhibition of Bacillus sphaericus and their toxic effect on the viability of the organism are illustrated and discussed in comparison with results obtained from the microcrystalline TiO2. The results show 90% reduction of the B. sphaericus cell viability at 10g/L concentrations of TiO2NPs under fluorescent light (400-700 nm) after 60 min irradiation. In contrast, a 40% reduction was observed for microcrystalline TiO2 (as determined by plate count assay) and scanning electron microscopy (SEM). In particular, the toxicity of both microcrystalline TiO2 and TiO2 NPs was also observed in the dark although with reduced influence. TiO2 NPs were found to exhibit bacteriostatic and photocatalytic effect on B. sphaericus as exposure time increases. Results of this study suggests that a longer exposure time could impact bactericidal activity. The results of the study showed that photocatalytic inactivation of paint bacteria can be directly linked to time of exposure.
- ItemOpen AccessBacteria with dual resistance to elevated concentrations of heavy metals and antibiotics in Nigerian Contaminated Systems(2009) Oyetibo, G.O.; Ilori, M.O; Adebusoye, S.A.; Obayori, O.S.; Amund, O.OSamples 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.
- ItemOpen AccessBacteria with dual resistance to elevated concentrations of heavy metals and antibiotics in Nigerian Contaminated Systems.(Oyetibo, et al (2010). Bacteria with dual resistance to elevated concentrations of heavy metals and antibiotics in Nigerian Contaminated Systems. Environ Monit Assess 168:305–314, 2009) Oyetibo, G.O; Ilori, M.O; Adebusoye, S.A; Obayori, O.S; Amund, O.OSamples 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.
- ItemOpen AccessBacterial and fungal biodeterioration of discolored building paints in Lagos, Nigeria(Springer, 2017-09-27) Obidi, O.; Okekunjo, F.Microbial induced discolorations are an unsightly feature occurring on painted walls in Lagos, the commercial hub of Nigeria. Very few studies have been carried out conventionally about the microbial community structure of discolored painted walls in Nigeria therefore, knowledge of the true microbial diversity is elusive. To further our understanding of the phylogenetic diversity of representative microbial community on 40 discolored and three clean-looking buildings, a comparative DNA sequence analysis of 16S rDNA genes was undertaken. Following DNA extraction, portions of the rDNA genes were amplifed by PCR and sequenced. Resulting sequences were compared with GenBank data base sequences. Fifteen unique fungal sequences and one bacterial sequence were obtained. Majority (37.50%) of rDNA sequences analyzed, represent the genus Meyerozyma of which the novel fungus Meyerozyma guilliermondii, which to our knowledge, has not yet been implicated in painted walls was detected. Clones from the discolored painted wall isolates also produced a data set in which 31.25% of sequences were related to Fusarium proliferatum and 6.25% were Pseudomonas aeruginosa. The remaining sequences clustered with members of the genera Candida (6.25%), Aspergillus (12.5%) and Cerrena (6.25%). The study provides reliable data on microbial communities on painted walls and information for paint biocide formulation.
- ItemOpen AccessBiocontrol of Fusarium wilt of cucumber with Trichoderma longibrachiatum NGJ167 (Rifai)(British Microbiology Research Journal, 2016-08-26) Kareem, T. K.; Ugoji, E. O.; Aboaba, O. O.Aim: This research investigated the use of Trichoderma longibrachiatum NGJ167 (Rifai) as a biocontrol agent of Fusarium wilt in cucumber varieties (Ashley and Marketmoor) both in the screenhouse and on the field. Study Design: The screenhouse experiment was laid down in a Completely Randomized Design (CRD) while Randomized complete block design (RCBD) was used for the field experiment. Place and Duration of Study: The study was conducted at the National Horticultural Research Institute, Ibadan between 2012 and 2013. Methodology: Soils were inoculated with mycelial plugs of T. longibrachiatum NGJ167 before planting while the control soil was mock-inoculated with agar plugs of Potato dextrose agar (PDA). Two weeks after planting, F. oxysporum was inoculated into the soils in the screenhouse while natural infection was allowed to occur on the field. The biocontrol abilities of T. longibrachiatum NGJ167 on F. oxysporum was observed on disease incidence and severity and the fruit yield. The presence of T. longibrachiatum NGJ167 genes was detected in the treated cucumber fruits to ensure consumers’ safety. Results: The control plants had higher incidence and severity of F. oxysporum than the T. longibrachiatum-treated plants. The T. longibrachiatum NGJ167-inoculated Marketmoor had higher fruit weight value of 200g in the screenhouse when compared with the control which had a fruit weight value of 133.33 g. On the field, T. longibrachiatum-treated Marketmoor produced the highest fruit weight of 220 g while the control had a mean weight of 120.6 g. Results also revealed that T. longibrachiatum DNAs were absent in the inoculated cucumber fruits. Conclusion: The use of T. longibrachiatum NGJ167 as a biocontrol agent indicates its potentials in improving plant health in agriculture. The absence of T. longibrachiatum NGJ167 in the treated cucumber indicated that the consumption of such fruits will have no adverse effect on consumers’ health.
- ItemOpen AccessBiodegradation of Polycyclic Aromatic Hydrocarbon Mixtures by Rhodococcus Pyridinivorans FF2 and Pseudomonas Aeruginosa F4b Isolated from Sediments of Lagos Lagoon, Nigeria(Biogeneric science and Research, 2020) Obi, C.C; Adebusoye, S.A; Amund, O.O; Ugoji, E.E; Hickey, W.JPolycyclic 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 ring-hydroxylating 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.
- ItemOpen AccessBiodegradation and detoxification of Scarlet RR dye by a newly isolated filamentous fungus, Peyronellaea prosopidis(Elsevier, 2018-03) Bankole, P.O.; Adekunle, A.A.; Obidi, O.F.; Chandanshive, V.V.; Govindwar, S.P.Efficient mitigation and management of environmental pollution caused by indiscriminate disposal of textile industry dyes and effluents deserves special attention. The aim of the present study was to evaluate the efficiency of Peyronellaea prosopidis for the decolorization, degradation and detoxification of Scarlet RR dye. Ultraviolet visible spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, High-Performance Liquid Chromatography and Gas ChromatographyeMass Spectrometry (GCeMS) were used in analyzing the degraded metabolites of the dye. P. prosopidis showed decolorization potency on Scarlet RR dye, dye mixture and textile industry dye effluent at a concentration of 10 mg L 1 and up to 90, 84 and 85% within 5 d. Maximum decolorization of Scarlet RR dye (10 mg L 1) by P. prosopidis was achieved at pH 6, temperature (35 C) and biomass dose (1 g). Furthermore, 68, 88 and 91% reduction was recorded in the biological oxygen demand, chemical oxygen demand and color intensity of the textile industry effluent, respectively, after treatment with P. prosopidis. The degradation mechanism mediated by enzymes revealed significant inductions in lignin peroxidase (85%), laccase (58%), and manganese peroxidase (48%) after treatment of Scarlet RR dye with P. prosopidis. FTIR spectra of the metabolites showed significant disappearance and shifts in peaks in comparison with controls. Metabolites obtained from the GCeMS analysis were: N-(1l3-chlorinin-2-yl)-2-{methyl[(4-oxo-3,4-dihydroquinolin-2-yl)methyl]amino}acetamide; N- (1l3-chlorinin-2-yl)-2-{[(4-oxo-3,4-dihydronaphthalen-2 yl)methyl]amino}acetamide; 5-({[2-(1l3-chlorinin-2-ylamino) ethyl]amino}methyl)cyclohexa-2,4-dien-1-one and N-ethyl-1l3-chlorinin-2-amine after degradation of Scarlet RR dye. The detoxified status of the dye metabolites was confirmed with significant growth of plumule and radicle.
- ItemOpen AccessBiodegradation of crude oil and phenanthrene by heavy metal resistant Bacillus subtilis isolated from a multi-polluted industrial wastewater creek(International Biodeterioration & Biodegradation (ELSEVIER), 2017-02) Oyetibo, G.O; Chien, M.F; keda-Ohtsubo, W; Suzuk, H; Obayori, O.S; Adebusoye, S.A; Ilori, M.O; Amund, O.O; Endo, OA 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 Co2þ and Ni2þ (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 postinoculation. 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.