Biodegradation of Hydrocarbon Pollutant Soil by Indigenous Microbes

Abstract

 Petroleum commonly referred to as oil, is a naturally occurring liquid found in rock formations. It consists of a complex mixture of hydrocarbons of various molecular weights, plus other organic compounds. Spilling of oil is the release of a liquid petroleum hydrocarbon into the environment, it is toxic to almost all forms of life. The main cause for the water and soil pollution is due to petroleum based products. Degradation is a treatment method used to remediate a variety of contaminants, including soil contaminated with petroleum hydrocarbons. Microbial degradation is the major and ultimate natural mechanism by which one can clean up the petroleum hydrocarbon pollutants from the environment. The hydrocarbon contaminated soil samples were collected from different regions (Coimbatore and Pollachi) and collected soil samples were determined for the hydrocarbon content by cold extraction method. The microorganisms were isolated from the sample through serial dilution method and then different colonies were picked and inoculated in petrol amended medium (1%) and incubated for 24 hours. After the incubation period the isolates that showed better growth was selected. The selected isolates were nearly identified according to the biochemical test were found to be as Psuedomonas sp, Corynebacterium sp.and Eshrechia sp. These isolates were amended with 1% petrol in the MSM medium and incubated for 24 hours and under shaking condition, after the incubation period the liquid phase was collected and analysed spectrometrically at 420nm for degradation study. An edible mushroom Pleurotus ostreatus was cultivated, in the collected petroleum contaminated soil and the compost was prepared the isolated strain was added to the spent mushroom compost (SMC) to stimulate the activity of indigenous microflora. After 15 days the spent soil used were determined for TPH analysis and Psuedomonas sp showed a high level of decreased TPH rate when compared with other two organisms .