Double Bond-Transferring Novel Hydroxylation Reaction Involved in Microbial Metabolism of Plant Essential Oil Eugenol

We isolated a eugenol-degrading bacterium Pseudomonas fluorescens E 118.This strain produced a novel enzyme,eugenol dehydrogenase which catalyzes the formation of coniferyl alcohol from eugenol.The enzyme required an electron acceptor such as phenazione methosulface(PMS).The enzyme was purified 242-fold with a 22.4% overall recovery from the eugenol-induced cells of P.fluorescens E118.The purified enzyme appeared to be homogeneous,judging from the analysis of polyacrylamide gel electrophoresis.The enzyme was a 68.6 kDa protein composed of two different subunits (α　subunit 10.4kDa and βsubunit 58.2kda).The enzyme exhibited a cytochrome c-like absorption.The α subunit containing heme c seemed to play an important role for the dehydrogenation reaction.The enzyme also catalyzes the dehydrogenation of 4-alkylphenol into the corresponding alkyl 1-(4-hydroxyphenyl)-alcohol,and vanillyl alchol into vanillin,respectively.The reaction products were isolated and identified.These reaction seemed to proceed through the same mechanisms.