The Metabolism of 1,2-Propanediol by the Facultative Methylotroph Pseudomonas AM1

Pseudomonas AM1 grows on 1,2-propanediol with a mean doubling time of 7 h. The growth responses of a wide range of mutants suggest that propanediol is assimilated into cell material by way of pyruvate and acetyl-CoA. The normal enzymes for the initial metabolism of propanediol [NAD(P)+-linked dehydrogenase, propanediol oxidase and propanediol dehydratase] were absent. The initial oxidation of propanediol was catalysed by methanol dehydrogenase but only in the presence of a large molecular weight (possibly protein) stimulatory factor that seemed to change the substrate specificity of the enzyme; the product of the oxidation was lactate.