Journals Proceedings

Abstract

Polychlorophenols such as pentachlorophenols and trichlorophenols are major environmental pollutants. Tetrachlorophenol can be naturally produced while pentachlorophenol is anthropogenic in origin. The main sources of polychlorophenol contamination are from their production, application & discharge. Polychlorophenols are harmful to all life forms because they disrupt the integrity and function of biological membranes. Their metabolites are also toxic. The most efficient and economical approach for removal of polychlorophenols is bioremediation. Bacteria can degrade polychlorophenols under both aerobic and anaerobic conditions and fungi are able to aerobically metabolize them. The aerobic breakdown of aromatic compounds starts with monooxygenases or dioxygenases that introduce hydroxyl groups into the aromatic rings and further channelizes the metabolites into TCA cycle for the complete mineralization. However polychlorophenols are converted to substituted quinols before ring cleavage. In the present study we have isolated a microorganism capable of degrading high concentrations of polychlorophenols. The microorganism has been identified as Arthrobacter citreus by biochemical studies. Studies have revealed that the enzyme machinery which is capable of degrading ordinary phenols,nitrophenols,halophenols and cresols are also capable of degrading polychlorophenols. Identification of metabolites by TLC and Spectroscopic methods are indicative of the degradative pathway involving the formation of tetrachloroquinone, tetrachloroquinol, trichloroquinol, dichloroquinol, chloromalylacetate and ketoadipate which enters the TCA cycle.