Int.J.Curr.Microbiol.App.Sci (2015) 4(4): 429-461 429 Review Article An Environmental Cleanup Strategy - Microbial Transformation of Xenobiotic Compounds Nikki Agrawal* and Ashwini Kumar Dixit Department of Botany, Guru Ghasidas Vishwavidyalaya Koni, Bilaspur (Chhattisgarh) India *Corresponding author ABSTRACT Introduction The progress in science, technology and industries a huge amount of anthropogenic compounds ranging from raw sewage to nuclear wastes is released into the environment. These anthropogenic compounds are xenobiotic compounds which are toxic to living organisms and cause a global concern. Xenobiotic compounds are relatively persisting in the environment because they are highly thermodynamically stable. Xenobiotic compounds can have various toxic effects on humans; they exhibit acute carcinogenic, mutagenic, and teratogenic effects. The overall damage in ecosystem caused by xenobiotic compounds has motivated researchers to develop new strategies for their removal from the contaminated environment. The application of microbial technology for the biodegradation of xenobiotics from biosphere has received much attention. Xenobiotics are those chemical compounds that are foreign to a living organism. Human activity creates a lot of recalcitrant xenobiotic compounds. According to Sinha et al. (2009) principal xenobiotics include alkanes, polycyclic aromatic hydrocarbons International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 4 Number 4 (2015) pp. 429-461 http://www.ijcmas.com Due to continuous accumulation of recalcitrant xenobiotic compounds into the ecosystem released from various sources caused a serious global concern. Xenobiotics compounds are carcinogenic, mutagenic, causing teratogenic effect and persist over a long period of time in the environment. Microorganism exhibit capability to degrade xenobiotics by their metabolic pathways. Specific catabolic genes are found in a microorganism which are helping in horizontal gene transfer facilitated the rapid microbial transformation of xenobiotic compounds. Molecular- biology-based techniques including DNA fingerprinting, microarrays and metagenomics are used for monitoring and identification of novel bacteria involved in degradation of xenobiotics. These reviews provide an overview of microbial degradation process and catabolic genes, molecular techniques to study the microbial transformation of xenobiotic compounds in modern day technology. Keywords Xenobiotics, bioremediation, microbial enzymes, catabolic genes, horizontal gene transfer