A survey of the occurrence of a no. of enzymes possibly involved in the C1 dissimilatory pathway in organisms using the serine pathway of C assimilation indicated that neither the methanol dehydrogenase nor the NH4-independent dye-linked formaldehyde dehydrogenase had a specific role in the oxidn. of formaldehyde. Conversely, the activities of enzymes involved in the methenyl-THF pathway were induced during growth on MeOH or MeNH2, suggesting a potential dissimilatory role for this pathway. [on SciFinder (R)]