Comparative Analysis of the Impact of Crude Oil and Kerosene on Soil Microbiota and the Bio-utilization Potentials of the Indigenous Microorganisms

Abstract

This research is focused on evaluating the impact of crude oil and kerosene on soil microbiota. The enumeration of total heterotrophic bacterial count revealed that the soil impacted with crude oil and kerosene yielded low microbial counts ranged from 3.2 × 106 CFU/g, 3.2 × 105 to 2.6 × 103 CFU/g while that of total coliform count obtained from the samples ranges from 2.6 × 105CFU/g to 2.2 × 103 CFU/g. and total fungal count ranged from 2.0 x 102 CFU/g to 1.4 × 102 CFU/g.  The genera of bacteria isolated from soils impacted with crude oil and kerosene belong to the genera: Pseudomonas spp., Bacillus spp., Staphylococcus spp., Streptococcus spp., Escherichia coli, Micrococcus spp., Klebsiella spp., Corynebacterium and Salmonella species while Aspergillus spp., Alternaria spp., Candidia spp., Fusarium spp., Trichoderma spp., Mucor spp., Penicillium spp., Cephalosporium spp., Rhizopus spp. are the isolated fungi. The percentage occurrence revealed that Pseudomonas spp. and Escherichia coli had the highest prevalence of 23.1%, followed by Staphylococcus spp. (7.7%), Salmonella spp. (7.7%), Bacillus spp. (7.7%), Micrococcus spp. (7.7%) etc. While the fungal isolates had the following prevalence; Aspergillus spp. (12.5%), Penicillium spp. (12.5%), Candida spp. (12.5%), Mucor spp. (12.5%), etc.  The results obtained indicates that crude oil and kerosene have a negative impact on the microbiota of the soil. The combined effect of the compounds is more harmful than their individual effects. This result implies that farmlands impacted with these products would not be suitable for agricultural purposes since the nitrogen fixing bacteria and other soil enriching microorganisms must have been either killed or inactivated by the toxicity of compounds.