ISOLATION OF OIL DEGRADING BACTERIA FROM ENGINE OIL CONTAMINATED SOIL

Contamination of soil surface by used lubricating oil is a common occurrence in most developing countries. These hydrocarbon pollutants have harmful effects on the environment and human beings. Using hydrocarbon degrading microbes can be an alternative green technology for remediation of contaminated soil. The purpose of the present work is to evaluate the effectiveness of microorganisms indigenous to the soil in remediating the soil pollutant. Used engine oil contaminated soil samples were collected from service stations and motor garages located in Kirathoor, Mankadu and Nithiravilai of Kanniyakumari District. Hydrocarbon utilizing bacteria was isolated by its lipase producing activity. Oil utilization efficiency is estimated by counting total cell number of microbes at 24 h and oil displacement assay. A total of thirteen hydrocarbanoclastic bacteria were isolated from Kirathoor, Mankadu and Nithiravilai workshops engine oil contaminated soil. Among the thirteen bacteria only seven are identified as lipase producing bacteria and are identified as Acenetobacter, Pseudomonas and Proteus. Maximum of oil utilization efficiency was observed in Acenetobacter and Pseudomonas species at 2% and 4% of oil supplementation respectively. Proteus and Acinetobacter species showed positive result in oil displacement assay indicating the secretion of biosurfactant to degrade spilled oil. From the present work it is concluded that biosurfactant producing bacteria can be used for remediating oil spill area.