A novel inducible formaldehyde dehyrogenase of Pseudomonas sp. (RJ1)

A novel, pyridine-nucleotide-independent, inducible formaldehyde dehydrogenase acitivity was detected in cells of Pseudomonas sp. (RJ1) propagated on methylamine and oxalated. The pH optimum of the dehydrogenase was 7.0. Dichlorophenol-indophenol or potassium ferricyanide served as an electron acceptor. The rate of reduction of these electron acceptors was shown to be stimulated by phenazine methosulfate. The dehydrogenase was inhibited by parahydroxymercuric benzoate and iodoacetamide. This inhibition suggests that the enzyme contains sulfhydryl groups. The stoichiometry of the reaction in terms of oxygen uptake to formate formation was 0.5, which agrees with the theoretical value.