DISTRIBUTION, CHARACTERIZATION AND HYDROCARBON– DEGRADING POTENTIALS OF MICROORGANISMS IN SOME PARTS OF BIDA BASIN, NIGERIA

Abstract

The distribution and characterization of a suspected petroleum bearing site (SPBS) is generally called microbial prospecting. Microbial surface prospecting is a vital process in the exploration of hydrocarbon suspected site. This study was aimed at assessing the distribution, characterization and hydrocarbon degrading potentials of microorganisms in some parts of Bida Basin, Nigeria. The study assessed the physicochemical and microbiological properties of soil and water from Ahoko, Kogi State, and Patishabakolo, Niger state, Nigeria, to ascertain the potent site for exploration using the presence of microbial anomalies. Standard plate count, ArcGIS, gravimetric and GC MS methods were used to ascertain the total bacterial and total fungal counts, distribution of specific hydrocarbon–oxidizing microbes and hydrocarbon-degrading potential of isolates respectively. Physicochemical properties showed that pH of the soil samples were within the range of 5.58 – 7.05. Site A had the highest total organic carbon (TOC) (1.18%), conductivity (12.0 μ∫/cm), available Phosphorus (12.06 mg/kg), base saturation (66.03 ± 0.00%) and exchangeable acid (2.28 cmol/kg) compared to other sites in Ahoko. The physicochemical parameters such as pH, TOC, conductivity and total pore space in samples from Patishabakolo vary from 5.30-6.81, 1.75%-8.78%, 0.10µʃ-2.0µʃ/cm and 160.8%-192.3% respectively. The study revealed the presence of counts for methane-oxidizing microbes (MOM) (4.8 x 102 CFU/mL, 5.0 x 102 CFU/mL), ethane-oxidizing microbes (EOM) (4.6 x 102 CFU/mL, 10.0 x 102 CFU/mL) propane-oxidizing microbes (POM) (3.6 x 102 CFU/mL, 10.0 x 102 CFU/mL) and Butane oxidizing microbes (BOM) (2.80 x 102 CFU/mL, 6.65 x 102 CFU/mL) in water samples from Ahoko, and Patishabakolo respectively. There were significant differences (p<0.05) in counts of the various groups of bacteria except for BOM. In general, the EOM predominated in all study sites and areas. The EOM was the most widely distributed across all the study locations and there were correlative relationship (r = 0.9) between EOM and BOM. The most frequently encountered bacterial and fungal hydrocarbon-gas utilizers were Corynebacteria, Acinetobacter, Micrococcus and A. niger and A. flavus respectively. Ten crude oil–utilizing organisms which included one bacterium and 9 fungi were amplified using using universal primers. The organisms were identified as, Enterobacter asburiae RSo-A, Aspergillus flavus A-Feb, A. tubingensis D2S3, Alternaria tenuissima JYW, A. flavipes BH A. terreus JYS, Penicillium pimiteouiense JS-B, Aspergillus sublatus D1S4, Aspergillus stellatus Borehole, and Candida orthopsilosis JS-A. The rate of crude oil degradation by the identified organisms was determined after 35 days of incubation, using gravimetric analysis method. The results revealed that 68.9 %, 73 %, 68.4 %, 62 %, 72.11 %, 77.8 %, 83.68 %, 68.89 %, 88.05 %, and 85 % degradation were respectively achieved by the organisms. Biodegradation potential of isolates were observed by conversion of high molecular weight (HMW) compounds to low molecular weight (LMW) compound, reduction in the height of peaks and the concentrations of carbon content as well as presence and emergence of intermediates compounds. All the isolates used in this study utilized the crude oil luxuriantly but isolates of C. orthopsilosis JS-A and A. stellatus borehole were the most effective and efficient degraders, achieved 85 % and 88 % rate of degradation and was able to completely remove 9 and 13 carbon compounds from the crude oil mixture respectively. Hence, they can be used as clean up agents in oil spills in future if oil exploration begins in these zones.