Physiological and biochemical characterization of the recombinant strain of methylotrophic yeast Hansenula polymorpha HBS-30

Biochemical and physiological properties of the recombinant strain of H. polymorpha HBS-30 carrying the integrated plasmid pHBS-30 with the gene encoding the surface antigen of hepatitis B virus were studied in the chemostate mode. The data suggest that ATP deficiency in this strain causes a rate-limiting step catalyzed by dioxyacetone kinase in the assimilation of formaldehyde that leads to its accumulation. To reduce the toxicity of formaldehyde, the cell slows down its synthesis by deactivating methanol oxidase and accelerates its oxidation by raising the activity of formaldehyde dehydrogenase.