Isolation and Characterization of Two Methanol-utilizing Bacteria

Two bacterial strains capable of growth on methanol, methylamine, formaldehyde and formate, as sole sources for carbon and energy have been isolated and designated as Pseudomonas 1 and Pseudomonas 135. These bacteria are gram-negative, motile rods. The mean generation time of Pseudomonas 1 is 4 hr on 0.3 % methanol at 32°C, and that of Pseudomonas 135 is 5 hr. Extracts of Pseudomonas 1 and Pseudomonas 135 possess activities of methanol, formaldehyde and formate dehydrogenases when grown on methanol; and methylamine dehydrogenase when grown on methylamine. While no hexulose phosphate synthase activities were detected in extracts of these bacteria, high activities of hydroxypyruvate reductase and methylene tetrahydrofolate dehydrogenase were found indicating the assimilation of C₁-compounds via the serine pathway and not via the ribulose monophosphate pathway.