DIHYDROXYLATION AND DECHLORINATION OF CHLORINATED BIPENYLS BY PURIFIED BIPHENYL 2,3-DIOXYGENASE FROM PSEUDOMONAS SP STRAIN LB400

Oxidation of biphenyl and nine chlorinated biphenyls (CBs) by the biph enyl 2,3-dioxygenase from Pseudomonas sp, strain LB400 was examined. T he purified terminal oxygenase required the addition of partially puri fied electron transport components, NAD(P)H, and ferrous iron to oxidi ze biphengl and CBs. cis-Biphenyl 2,3-dihydrodiol was produced with bi phenyl as the substrate. Dihydrodiols were produced from all CBs, and more than one compound was produced with most substrates, Catechols we re produced when the dioxygenase-catalyzed reaction occurred at the 2, 3 position of a 2-chlorophenyl ring, resulting in dechlorination of th e substrate. Oxidation at the 3,4 position of a 2,5-dichlorophenyl rin g produced a 3,4-dihydrodiol. Compounds resulting from both types of r eaction were produced during oxidation of 2,5,2'-trichlorobiphenyl. Th e broad substrate specificity and the ability to oxidize at different ring positions suggest that the biphenyl 2,3-dioxygenase is responsibl e for the,vide range of CBs oxidized by Pseudomonas sp. strain LB400.