IJSRSET151446 | Received: 22 July 2015 | Accepted: 05 August 2015 | July-August 2015 [(1)4: 207-215] © 2015 IJSRSET | Volume 1 | Issue 4 | Print ISSN : 2395-1990 | Online ISSN : 2394-4099 Themed Section: Science 207 Biodegradation of Benzene under Anaerobic Condition using Enriched Microbial Culture Shalini Gupta, Bhawana Pathak, M H Fulekar School of Environment and Sustainable Development, Central University of Gujarat, Gandhinagar, Gujarat, India ABSTRACT Benzene is a highly toxic organic contaminant having carcinogenic potential and a serious ground water contaminant. Refinery industry is a major source of benzene contamination in the environment. The present paper focuses on biodegradation of benzene under anaerobic condition by using enriched microbial consortium. Enriched bacterial isolates, identified by 16S rRNA sequencing technique were taxonomically 99% similar to Bacillus cereus strain BC2, Citrobacter freundii strain : A11-1, Bacillus cereus strain SS263-3, Brevibacterium linens strain S402003. A bioreactor was designed & developed for the study of biodegradation of benzene with different concentrations (5, 10, 25 ppm). 94.3 % degradation was observed in 5 ppm followed by 10 and 25 ppm i.e. 67.08 % & 51.3 % respectively. Results of this study indicated that these genera may play an active role in bioremediation of benzene. Keywords: Biodegradation, Benzene, Anaerobic, Enriched, Microbial Culture I. INTRODUCTION Industrialization and technological advancement has resulted into generation of huge amount of liquid and solid waste which is a concern to environmentalist. Manufacturing exploration, extraction processes use raw materials and consumables from each component of environment, and release of hazardous waste which results into deleterious effects on the surrounding environment. The main sources of contaminants are the chemical industries, e.g. petrochemical industry which involves the production of several chemicals, basic raw materials and key intermediates, generate complex hazardous waste. The most common aromatic organic compound found in the waste discharge by the industry is benzene. Benzene is among the most prevalent organic contaminants in groundwater and is of major concern due to its toxicity and relatively high solubility [1, 2]. It possesses a major threat to human health and environment due to its toxicity and carcinogenic effects. Clean-up of the contaminant is needed in order to avoid public health hazard. Conventional methods of treatment of volatile organic wastes have been largely physical or chemical but these can also lead to secondary pollutant problems. The ecologically acceptable disposal of organic waste remains a major challenge to the petrochemical industry. Bioremediation is an increasingly popular alternative to conventional methods for treating waste compounds using natural microbial activity. It is expected to be an energy efficient, economical and environmentally sound approach. With this view the present study was undertaken with the refinery effluent to isolate promising bacteria for bioremediation of benzene. II. METHODS AND MATERIAL 2.1 Sample Collection Wastewater sample was collected from effluent treatment canal of Indian Oil Corporation limited (IOCL), located at Koyali near Vadodara, Gujarat, India, with the following location coordinates: Latitude; 22.37425, Longitude; 73.11948. 2.2 Physico-Chemical and Microbial Characterization Physical and chemical parameters were analyzed by standard methods [3]. Total organic carbon and heavy metals were analyzed by total organic carbon (TOC)