ABSTRACT

 Samples were collected from diesel engine generator sites, mechanic workshop and filling station. One sample was collected from diesel oil free environment. The soil samples were analyzed for Total Heterotrophic Bacteria (THB), Fungal Count (TC), Hydrocarbon Utilizing Bacteria (HUB) and Hydrocarbon Utilizing Fungi (HUF). Total Heterotrophic Bacteria Count ranged from 1.73x107– 4.94 x 107while Total Fungi Count ranged from 1.28 x 107 – 2.1 x 107.The bacteria isolated were Bacillus spp., Pseudomonas spp., Micrococcus spp., Escherichia coli, Klebsiella spp., and Serratia spp. Bacillus spp., Micrococcus spp., and pseudomonas spp., showed heavy growths as all the organisms grow in the diesel media at different rates. The fungi isolated were Aspergillus spp., Fusarium spp., and Rhodotorula spp. Aspergillus showed the highest occurrence of growth among the fungi isolated. Analysis of Variance (ANOVA) of the mean count was done. From the chart, the uncontaminated soil (control) had the highest occurrence in Total Heterotrophic Bacteria count among others. The following physico-chemical properties of pH, conductivity, oil and grease, Mg2+, PO4, SO4, NO3, TPH, and TOC were done during the course of this study. Diesel pollution increased the concentrations of NO3, SO4, TPH, Mg2+, PO4, pH, TPH and TOC of the contaminated soil compared to the control. The result showed that the pollution of soil with diesel oil causes great effects on soil physico-chemical characteristics and thus affects microbial nature and population of such soil.