抄録
The enzymatic decomposition of phenyl mercuric acetate (PMA) to metallic mercury by a mercury-resistant Pseudomonas has been studied. The formation of the system involved in the decomposition was found to be inducible. Glucose dehydrogenase (D-glucose: NAD oxidoreductase), arabinose dehydrogenase (L-arabinose: NADP oxidoreductase), cytochrome c and the “decomposing enzyme” which catalyzes the splitting of the C-Hg linkage, were separated from cell free extract by gel filtration on a column of Sephadex G-150. The cytochrome fraction was further separated into two types, c-I and c-II, by chromatography on a column of CM-Sephadex. Each of these cytochromes showed absorption peaks at 416, 519 and 547mμ fe in the reduced form, but they were different in the molecular weight; cytochrome c-I was estimated to be about 26000, and cytochrome c-II about 14000. The reconstruction of these enzymes demonstrated that a reduced NAD(P) generating system, glucose dehydrogenase or arabinose dehydrogenase, cytochrome c-I and the “decomposing enzyme” were required for the decomposition of PMA. A hypothetical scheme for the decomposition of PMA was proposed and the decomposition mechanism was discussed.
