VERIFICATION OF THE ROLE OF PCP 4-MONOOXYGENASE IN CHLORINE ELIMINATION FROM PENTACHLOROPHENOL BY FLAVOBACTERIUM SP STRAIN ATCC-39723

The bacterial enzyme PCP -4 monooxygenase from Flavobacterium sp. stra in ATCC 39723 catalyzes the oxygenolytic removal of the first chlorine from pentachlorophenol. PCP 4-monooxygenase is an FAD binding, NADPH requiring oxygenase. with similar functional domains as other bacteria l flavoprotein monooxygenases specific for phenolic substrates. Howeve r, the definitive proof for the singular role of an oxygenolytic elimi nation of the primary chlorine from pentachlorophenol by Flavobacteriu m sp. has awaited the development of a genetic system whereby targeted mutagenesis via allelic exchange could be carried out with the corres ponding gene from PCP 4-monoxygenase, pcpB. We report the development of a genetic system fur Flavobacterium sp. strain ATCC 39723, and ita application in targeted mutagenesis of the pcpB allele for elimination of PCP 4-monooxygenase activity. (C) 1996 Academic Press, Inc.