The excessive use of natural resources and large scale synthesis of xenobiotic compounds have generated a number of environmental problems such as contamination of air, water and terrestrial ecosystems, harmful effects on different biota, and disruption of biogeochemical cycling 5.Organophosphorus compounds (OP), are group of highly toxic agricultural chemicals 3. Some of these pesticides have also been reported to be toxic, mutagenic, carcinogenic and tumorogenic 13.
Malathion, S-(1,2-dicarbethoxyethyl)-O,O-dimethyldithiophosphate, is an organophosphate insecticide that has been used for some time as a DDT substitute for the control of field crop pests, household insects, flies and animal parasites. It has been known as the first organophosphorous insecticide with high selective toxicity 2. Malathion is powerful inhibitors of acetyl cholinesterase, an important enzyme involved in neurotransmission, in the form of acetylcholine substitutes 16. Environmental hazards and health risks caused by pesticides could therefore potentially affect human health and environment 16.
Therefore, remediation of contaminated sites is currently underway in order to develop safe, convenient and economically feasible methods for pesticide detoxification 19. Bioremediation is an environmental cleanup process that currently being investigated for use on a wide variety of chemical 16. The use of microbes in the bioremediation and detoxification of many toxic xenobiotics, especially toxic pesticide is an efficient tool for the remediation of contaminated sites in the environment 16. They have the capacity to utilize virtually all naturally and synthetically occurring compounds as their sole carbon and energy source 13. Bacteria, fungi and some plants have potency to degrade malathion 12. Malathion degradation products include dimethyl phosphate, dimethyldithiophosphate, dimethylthiophosphate, isomalathion, malaoxon and due to cutinase, carboxylesterase, phosphatase enzymatic activity, malathion is degraded into malathion mono and dicarboxylic acid 1.Mycodegradation is a deterioration phenomenon causing degradation by fungi in a wide variety of materials and compounds 6.Studies have been reported, the occurrence of several yeast such as Saccharomyces species, Candida species in various fermented dairy or dairy related product like curd, cheese, idli, dosa, jalibi, fruit, juices and brewery products 17.This paper focuses on biodegradation of Malathion by yeast isolated from idli batter.