Isolation of Bacteria and Physicochemical Analyses of Petroleum-Products Contaminated Soil from NNPC/PPMC Depot, Benin City, Nigeria

This study was aimed to evaluate the physico-chemical properties and presence of bacteria of from soil samples contaminated with different petroleum products which are petrol (PMS), diesel (AGO), pure kerosene (DPK) and mixed kerosene (DPK) obtained from the tank farm of NNPC/PPMC Depot in Benin City, Nigeria. The mean count for heterotrophic bacterial ranged from 1.83x 104±0.09 cfu/g soil contaminated with mixed DPK to 5.93x104±0.02 cfu/g for soil contaminated with PMS. Nine (9) bacterial isolates were characterized and identified; Bacillus subtilis, Micrococcus varians, Pseudomonas aeruginosa, Klebsiellaaerogenes, Alcaligenes sp., Corynebacterium sp., Bacillus sp., Arthrobacter sp., and Pseudomonas sp.Bacillussp. and Pseudomonassp. were the most occurring bacteria isolates in the four soil samples. From the physico-chemical analysis, the pH value ranged from 6.50-6.70, electrical conductivity ranged from 14.20mhos/cm-32.50mhos/cm, moisture content from 10.20%-14.50%, carbon from 1.38%-2.97%, nitrogen from 2.37%-8.19%, 0.396%-0.950%, phosphate 1.95%-5.52% and total hydrocarbon from 125mg/kg-3,050mg/kg These results revealed that the presence of these bacteria under the stated soil condition can enhance bioremediation of petroleum contaminated soil. This study reveals the possible biodegradability of several petroleum products by bacteria which will aid the bioremediation of the contaminated soil.