Abstract

A COMPARATIVE STUDY ON THE TOLUENE DEGRADING BACTERIA ISOLATED FROM POLLUTED ENVIRONMENTS

D.V. Varshini and *Dr. V. Judia Harriet Sumathy

Abstract

Humans are primarily exposed to various types of Pollutants and onesuch pollutant is Toluene. It is moderately toxic when ingested orinhaled and slightly hazardous when absorbed through skin. Toluenecan enter human body from the air, water or soil. When toluene isinhaled, it is directly taken into the blood from the lungs. When tolueneis ingested, it is absorbed from the GI tract into the bloodstream. Smallamount of toluene accumulates in fat tissue with daily exposure andmajority of toluene is removed from the body within a day. Tolueneleaves the body unchanged during respiration and excretion or it isconverted into a less harmful chemical such as hippuric acid.Bioremediation is the best practice of using living organisms todetoxify the polluted environment. There are three different types of bioremediation namely(a) Microbial bioremediation, (b) Phytoremediation and (c) Mycoremediation. The process ofusing microbes to degrade environmental contaminants to non harmful or less harmfulproducts is termed as microbial biodegradation which can occur aerobically or anaerobically.Aerobic degradation occurs when the pollutant is oxidised using oxygen, nitrogen, iron,sulphate and manganese by the microbes and the pollutant acts as electron donor. Anaerobicdegradation occurs when the pollutant is reduced by the microbes. The oxidative microbesdegrade toluene via hydroxylation of the aromatic ring to a mixture of catechols and cresols.The present research work is a Comparative study of bacteria isolated from pollutedenvironments that are capable of degrading toluene.

Keywords: Humans, Pollutants, Toulene, Bioremediation and Comparative Study.