RESEARCH ARTICLE SCIENCE INTERNATIONAL © 2014 Science International 20 DO I: 10.17311/sciintl.2014.20.25 Biodegradation of Petroleum Compound Using the Bacterium Bacillus subtilis K.V. Darsa, A. Joseph Thatheyus and D. Ramya 1 2 2 PostgraduateDepartment of Immunology and Microbiology, 1 Postgraduate and Research Department of Zoology, American College, Madurai, 625 002, Tamil N adu, India 2 ABSTRACT Background: With increasing demands of fossil fuel energy, extensive exploration of natural sources has caused a number of large scale accidental spills of crude oil and resulted in environmental disasters. The consequence of oil pollution to environment and human health has brought a serious challenge to environmental scientists. The aim of the present study is to evaluate the biodegradation of petrolum compound by Bacillus subtilis isolated from automobile workshops. Methods: Soil samples were collected from petrol bunks and workshops and subjected to serial dilution and plating. From the developed bacterial colonies, one was selected and identified as Bacillus subtilis based on the biochemical tests. The isolated strain was able to grow in minimal broth along with 2.5, 5, 7.5 and 10% concentrations of petrol which indicated the capability of the organism in degrading petrol and utilizing it as a source for growth. Results: The isolated strain’s efficiency was determined by analysing the parameters pH, optical density and CO 2 released during petrol degradation. HPLC analysis also confirmed the degradation of petrol by Bacillus subtilis. Conclusion: The isolate Bacillus subtilis has the ability to tolerate the petrol concentrations and grow on them. Hence, this strain can be used in cleaning oil polluted sites. Key words: Biodegradation, petroleum compound, Bacillus subtilis, petrol Science International 2 (1): 20-25, 2014 INTRODUCTION energy and as a primary raw material for chemical Oil contaminated wastewater has been identified as one of the most concerned pollution sources. This kind of wastewater is widely produced from a variety of sources such as crude oil production, automotive garage, oil refinery, petrochemical industry, metal processing, lubricant and car washing. These sources serve as the major contributor to the environmental problems especially in soil and water . Both the waste and unused 1 compounds from the prescribed sources are grouped as oily waste which is difficult to treat or recycle . 2 Petroleum contaminated soil contains various hazardous materials such as aromatic hydrocarbons and polycyclic aromatic hydrocarbons and they are potentially toxic, mutagenic and carcinogenic . 3 Multiple initiatives have been developed to resolve the problem of petroleum pollution. An array of procedures has been developed including physical, chemical and biological techniques. Among these procedures bioremediation is currently gaining importance. The demand of petroleum as a source of Corresponding Author: K.V. Darsa, Postgraduate Department of Immunology and Microbiology, American College, Madurai, 625 002, Tamil N adu, India Tel: 91- 9487424820 industries in recent years has resulted in an increase in world production. This dramatic increase in production, refining and distribution of crude oil has brought with it an ever increasing problem of environmental pollution . 4 The persistence of petroleum pollution depends on the quantity and characteristics of hydrocarbon mixture and on the properties of the affected ecosystem. The ability to isolate high numbers of certain oil degrading microorganisms from oil polluted environment is commonly taken as evidence that these microorganisms are active degraders in that environment . 5 Contamination of water with hydrocarbon wastes stimulates indigenous microbial populations, which are capable of utilizing the hydrocarbon substrates as their sole carbon and energy sources thereby degrading the contaminants. Several bacterial species have been identified as having the ability for oil degradation. In general, Bacillus sp. has been identified as petroleum hydrocarbon degrader and is known as naphthalene and 6 pyrene degrader . According to Sorkhoh , 368 isolates 7, 8 9 belonging to the genus Bacillus were isolated from desert samples and two strains of Bacillus were able to degrade 80-89% of crude oil (5 g LG) within five days at 60°C. 1