Full text loading...
Abstract
SUMMARY: The enzymic mechanism of D-and L-lactate catabolism was the same in several strains of Acetobacter and Gluconobacter. This was taken to indicate a close relationship between these groups. Both isomers were broken down by way of pyruvate and acetaldehyde to acetate. Identical reactions were carried out by two sets of enzymes of a different nature and localization, one particulate, the other soluble. All strains contained a constitutive, soluble pyruvate decarboxylase which required thiamine pyrophosphate and Mg++. When grown on lactate, a pyruvate decarboxylase was also present in the particulate fraction. No evidence was found for a pyruvate oxidase system. Acetaldehyde was oxidized by a particulate oxidase system and by NADP-and NAD-linked dehydrogenases. This last enzyme was activated by coenzyme A and glutathione. The particulate pyruvate decarboxylase was not very tightly bound to the particles, as it could easily be detached by washing with buffer. The oxidase systems could not be removed under these conditions.
- Received:
- Published Online: