Enrichment and Identification of Askarel oil (PCB blend) degrading bacteria enriched from landfill sites in Edo State, Nigeria.

Microbial degradation following aerobic biodegradation is one of the means used by microorganisms for the removal of persistent organic pollutants from the soil. Bacterial species namely: Pseudomonas, Micrococcus Arthrobacter and Acinetobacter capable of utilizing askarel oil (PCBs blend) were isolated from landfill soil samples from Uzogholo, Mgboaku and Auchi in Edo State of Nigeria. The isolation of these bacterial species followed an enrichment in minimal salt media were Askarel oil served as the sole carbon source. These bacterial isolates were characterized based on their cultural, morphological, biochemical characteristics and comparison with standard reference organisms. The potentials of these bacterial species to utilize askarel oil were assessed by measuring changes in the turbidity and pH of the enrichment medium containing varying concentrations of the Askarel oil. From the weekly results obtained, significant increases in the mean turbidity ranged between (0.065- 0.371) and decreases in mean pH ranged between (6.15- 3.55) for the 21 days incubation period. Some of the bacterial organisms exhibited remarkable utilization of askarel oil at different concentrations in 15μL and 20μL of the askarel minimal salt medium. From these findings, the bacterial species of remarkable potential can be isolated, re-engineered via biotechnology or bioaugmentation for effective remediation of landfill sites polluted with Polychlorinated biphenyls compounds and its derivatives in Nigeria

Degradation of Askarel (PCB Blend) by Indigenous Aerobic Bacteria Isolates from Dumpsites in Ore, Ondo State.Nigeria.

The removal of toxic industrial products such as polychlorinated biphenyls (PCBs) perchloroethylene (PCE) and trichloroethylene (TCE) in soils has become a daunting and necessary task. These compounds adsorb onto organic matter in the environment, making decontamination using traditional approaches difficult or ineffective. The use of microbes to transform these contaminants to non toxic degradation products is an alternative and imperative approach due to the prevalence of such organisms within the environment. In this study; the use of bacteria in the microbial degradation of polychlorinated biphenyls blend (Askarel) was explored. The notable bacteria isolated from dumpsites in Ore, Ondo state were identified using morphological and biochemical characteristics. These include: Pseudomonas, Micrococcus, Corynebacteria, Bacillus, Achromobacter and Arthrobacter species. The bacterial isolates potential to utilize Polychlorinated biphenyls blend (Askarel) as carbon source was investigated for twenty-one days period. From the results obtained, there was a general decrease in the pH and increase in mean Optical density (O.D); were the mean pH and O.D readings ranged between (3.08-6.02 and 0.060-0.557) respectively

Isolation and characterization of bacterial diversity from soils supplemented with electrical transformer fluids

Repetitive enrichment of soils samples from an agricultural land and newly marked dumpsite on electrical transformer fluid yielded six bacterial species that have the capacity to utilize electrical transformer fluids (askarel) as carbon and energy source. Bacterial species namely: Micrococcus, Arthrobacter, Pseudomonas putida, Pseudomonas spp, Norcadia and Corynebacterium were identified using morphological and biochemical characteristics. The abilities of these bacterial species to utilize the electrical transformer fluids as carbon source in minimal salt medium (MSM); sub cultured in concentrations of 5, 10, 15 and 20μL of electrical transformer fluids were investigated for twenty‐one days period. Physiological changes in terms of biomass increase were monitored by measuring the pH and optical density of the culture medium. From the results obtained, there was observed a general decrease in the pH and increase in Optical density (O.D). The mean pH and O.D readings ranged between (4.34‐6.13 and 0.073‐0.386) respectively. The decreased pH could justify for the acidic metabolites produced in the course of utilization of askarel as growth substrates. This study suggested that, the tropical ecosystems can provide exotic bacterial species that are capable of degrading or mineralizing polychlorinated biphenyls and their derivatives from dumpsites and agricultural soils

Antifungal effects of pawpaw seed extracts and papain on post harvest Carica papaya L. fruit rot

Increasingly, public debate on ban of use of synthetic chemicals for pest control has been unabated, due basically to the hazards posed by such chemicals to the ecosystem and environment. Biological control using natural products presents as alternative and a viable means of control of pests. Effects of extracts from Carica papaya. L (seed and papain) on mycelial reduction of the most occurring fungal pathogen causing pawpaw fruit rot were investigated. Different fungi isolated were Rhizopus spp, Aspergillus spp and Mucor spp. The aqueous seed extract and papain exhibited remarkable mycelial inhibition with mean zones of inhibitions between (0.23 - 1.73 mm). Using ANOVA at 5% (P < 0.05) there seem to be no significant difference in activity between the extracts (aqueous seed extract and papain).The importance of these findings is hinged on non- chemical means of shelf life elongation of harvested pawpaw fruit in Africa

SYNTHESIS AND EVALUATION OF ANTIMICROBIAL ACTIVITY OF PHENYL AND FURAN-2-YL[1,2,4] TRIAZOLO[4,3-a]QUINOXALIN-4(5H)-ONE AND THEIR HYDRAZONE PRECURSORS

A variety of 1-(s-phenyl)-[1,2,4]triazolo[4,3-a]quinoxalin-4(5H)-one (3a-3h) and 1-(s-furan-2-yl)-[1,2,4]triazolo[4,3- a]quinoxalin-4(5H)-one (5a-d) were synthesized from thermal annelation of corresponding hydrazones (2a-h) and (4a-d) respectively in the presence of ethylene glycol which is a high boiling solvent. The structures of the compounds prepared were confirmed by analytical and spectral data. Also, the newly synthesized compounds were evaluated for possible antimicrobial activity. 3-(2-(4-hydroxylbenzylidene)hydrazinyl)quinoxalin-2(1H)-one (2e) was the most active antibacterial agent while 1-(5-Chlorofuran-2-yl)-[1,2,4]triazolo[4,3-a]quinoxalin-4(5H)-one (5c) stood out as the most potent antifungal agent

Prevention of Escherichia coli biofilms Formation on Urinary Catheter by some Selected Plant Extracts

The challenge posed to the health sector by the use of catheter is as synonymous to its importance. Catheters encourage biofilm formation leading to bacteriuria, cystitis, urethritis, pyelonephritis and death in severe cases. This study was aimed at the prevention of E. coli biofilm formation using methanolic extracts of 3 different plants, Psidium guajava, Mangifera indica and Ocimum gratissimum. Plant extractions were carried using the solvent methanol via cold extraction. Varying concentrations of the extracts were prepared (5.0, 10.0 and 20.0 mg/mL) and used to coat 63 catheters using mild heat from water bath. Biofilm formation was analyzed using aerobic plate count and Optical density (OD600) count. From the results obtained Psidium guajava, Mangifera indica and Ocimum gratissimum were not able to prevent the growth E. coli species but delayed the onset of biofilm formation for about a week. Ocimum gratissium had the highest inhibitory effect at 5.0 mg/mL, 10.0 mg/L and 20.0 mg/mL with colony forming unit ranging from (2.2×105 -7.0×104 and 5.7×105- 3.7×105) for day 5 and 7 analysis respectively. Psidium guajava had the lowest inhibitory effect at these concentrations, with colony forming unit ranging from (4.3×105-1.9×103 and 7.7×105- 3.8×105) for day 5 and 7 analysis respectively. Although the three extracts varied in their antimicrobial capacity, the differences however, were statistically not significant. Psidium guajava, Mangifera indica and Ocimum gratissimum still remains a good choice against several pathogenic organisms and in ethnomedicine but can only be used for short term catheterizatio

Characterization of Diesel Degrading Bacterial Species from Contaminated Tropical Ecosystem

The bacterial diversity in a diesel contaminated tropical soil was investigated using diesel oxidation in gradient cultures dynamics (pH and OD) of the pure cultures. The diesel dependent growths of these isolates were assessed for 15 days by monitoring the gradient fluxes in the pH and Optical density OD of the media. Results showed an increase in OD as well as fluctuations in pH values. The mean OD data obtained was 0.515- 1.187 with pH of 6.95- 7.2. From the morphological and biochemical characterization and comparison with respect to the standard references, the isolates S1P1, S3P3, S2P2, S2P1,and S3P2 were presumably the members of the genera Bacillus, Pseudomonas and Mycobacterium species. From the study, it was apparent that the tropical ecosystems contained unique organisms with the ability to deal with diesel contamination

Evaluating the diesel biodegradation potential of wild microfungi isolat-ed from decaying wood in Nigeria

We evaluated the potentials of pure wild microfungi isolated from decaying wood in utilizing diesel as source of carbon/energy and monitoring of their physiological responses via OD and pH gradient fluxes. The fungi diversity was obtained by conventional enrichment culture methods. Pure cultures of tentative fungal species namely: SC1, SC2, SC3, YI and Y2 were tested for their ability to utilize diesel oil as carbon and energy source. From the cultur-al, morphological and biochemical characterization and comparison with respect to the standard reference of fungi, the wild microfungi tentatively named as SC1, SC2, SC3, YI and Y2 were seemingly the members of Penicil-lum, Aspergillus, Mucor, Candida and Cryptococcus species. The diesel de-pendent growth of the pure microfungi was assessed by monitoring the flux-es in the pH and Optical density OD of the minimal media slurry for 288 hours. There were fluctuations in OD as well as pH values for the different microfungi. The mean pH data 5.90 ± 0.01-7.01± 0.01 and the OD 0.349± 0.001 -1.232 ± 0.002 were obtained. The ability of our fungal isolates to tol-erate diesel and grow in it, suggests that the isolates can be employed as bioremediation agent

Growth Dynamics of Bacteria Isolated from Spent Engine Oil Contaminated Tropical Soil

Sites contaminated with spent oil in Canaan land Ota Nigeria were screened for the presence of spent oil degrading bacteria. The method of continual enrichment on the spent oil yielded five pure cultures that were selected for further physiological studies. From the morphological and biochemical characterization and comparison with respect to the standard references, the isolates were most likely the members of the genera Acinetobacter, Arthrobacter, Bacillus, Mycobacterium and Pseudomonas species. Time course studies of these organisms on the spent oil monitored by OD and pH fluxes resulted in exponential increases in the turbidity and steady declines in the pH. The mean OD obtained was 0.147±0.052-1.591±0.320 with pH 7.31±0.01-6.30±0.03. From the study, it was evident that bacterial species in tropical ecosystem can be explored for the recovery of sites polluted with spent engine oil