International Journal of Current Microbiology and Applied Sciences
ISSN: 2319-7706 Volume 2 Number 4 (2013) pp. 48-60
Isolation and Screening for Hydrocarbon Utilizing Bacteria (HUB) from Petroleum Samples
Varjani Sunita J.1 , Rana Dolly P.2 , Bateja S.2 and Upasani Vivek N.3 * 
1Gujarat National Law University (GNLU), Koba, GandhiNagar - 382007, Gujarat, India. 2 Institute of Reservoir Studies (IRS), ONGC, Ahmedabad-382015, Gujarat, India. 3Department of Microbiology, M. G. Science Institute, Ahmedabad - 380009, Gujarat, India. *Corresponding Author e-mail: 
The wide spread use of petroleum products leads to contamination of soil and aquatic environments, thereby poses a serious threat to all life forms including humans. Bioremediation is considered a cost-effective and environmentally safe method for treating oil polluted sites. Therefore, isolation of oil-degrading microorganisms and optimizing conditions for biodegradation process are important aspects of petroleum microbiology. Some important microbial species with this potential belong to the genera Arthrobacter, Halomonas, Pseudomonas, Bacillus, Klebsiella, Proteus, Aspergillus, Neurospora, Rhizopus, Mucor, Trichoderma etc. Microbial species differ in their biodegradation capabilities; therefore screening of potential hydrocarbon utilizing organisms is an essential process. Enrichment culture technique was employed to obtain sixty (69) bacterial isolates capable of utilizing crude oil as a carbon source from various soil and untreated effluent water (UEW) samples collected from various oil fields located in Gujarat. The average density of hydrocarbon utilizing bacteria (HUB) relative to the total viable count (TVC) of heterotrophic bacteria in the soil samples was 27.6 %, while in UEW samples was 15.8%. Screening for bacteria utilizing crude oil as the sole source of carbon with 2, 6-dichlorophenol indophenol (DCPIP) as redox indicator was carried out for all the isolates. Based on their capability to degrade hydrocarbons, six isolates were further selected and mixed to prepare a consortium which showed maximum utilization of hydrocarbons indicated by the total discoloration of DCPIP in just 53 hours. The results of this study are presented here. 
Bioremediation; BH medium; Crude oil; 2,6-DCPIP; HUB; UEW; UEW.