Abstract

One of the many catastrophes produced by mankind throughout history is the environmental deterioration that results from oil spills during extraction, processing, transportation, and corrosion of pipelines or damage. This study is aimed at assessing the microbiological and physicochemical characteristics of soil contaminated with crude oil and of an uncontaminated soil. The microbiological analysis revealed that total heterotrophic bacteria counts for the uncontaminated soil and contaminated soil was 4.77±0.47×10⁶CFU/g and 5.2±2.80×10⁸CFU/g respectively, Total Fungal counts was 4.3±0.96×10⁴ and 5.1±1.11×10³SFU/g respectively, Hydrocarbon Utilizing Bacteria counts 3.4±0.10×10⁴ and 3.9±0.59×10³CFU/g respectively, and Hydrocarbon Utilizing Fungal counts was 2.8±0.59×10⁴ and 3.0±0.53×10³ SFU/g respectively for uncontaminated and contaminated soil. The bacterial isolates identified from the uncontaminated soil were Serratia spp, Aeromonas spp, Micrococcus spp. Bacillus subtilis while Bacillus mycoides, Chryseobacterium spp, Bacillus thuringiensis, Pseudomonas spp. and Staphylococcus sp. from the contaminated soil. The fungal isolates identified from uncontaminated soil include Aspergillus spp., Trichoderma spp., Colletotrichum spp, and Aspergillus spp, Aspergillus spp. Penicillum spp, Fusarium spp. Aspergillus spp, Candida spp. Trichophyton spp. Alternaria spp. and Rhizopus spp from contaminated soil. The physicochemical parameters before and after crude oil pollution revealed pH to be 5.63±0.03 and 5.83±0.02, temperature 27.47±0.35 and 27.80±0.10, moisture content 12.17±0.11 and 45.77±0.25, electrical conductivity 78.33±0.25µS/cm and 19.43±0.21µS/cm. Nitrogen 9.15±0.03mg/kg and 3.63±0.04mg/kg, phosphorus 6.29±0.04mg/kg and 35.37±0.25mg/kg, potassium 12.17±0.05mg/kg and 22.47±0.15mg/kg, TOC was 0.65±0.03% and 0.37±0.02%e, SOM  1.15±0.03% and 0.69±0.01% for uncontaminated and contaminated soil respectively. It can be concluded that oil-degrading microorganisms are abundant in the soil contaminated with crude oil. This can be exploited for large oil-spill clean-up campaigns.