Detoxification of Organophosphate Pesticides Using Immobilized Enzymes

Abstract

Microbial enzymes which have the ability to degrade organophosphate insecticides are being examined to determine if such enzymes, either free or immobilized, may be used industrially for pesticide detoxification, and secondly, to establish if their economics will allow their use in environmental pollution control systems (degradative processes). In previous research (1) a mixed microbial culture was adapted to growth on parathion (0,0diethyl-O-nitrophenyl phosphorothioate) as the sole carbon and energy source. This gram negative, predominately pseudomonad culture (1,5) contained an enzyme(s) which had the ability to hydrolyze a wide range of organosphosphate insecticides (2) without the need for cofactors or special salts. Therefore, immobilization studies were started (3) to determine the feasibility of using immobilized parathion hydrolase for the detoxification of pesticides. A crude enzyme extract of specific activity 3-5 U/mg protein was obtained by disrupting cells by sonification and centrifuging at 10,000 x g for 15 min. 60% of the parathion hydrolase activity remained in the supernate after this treatment.