ENERGY BUDGETING IN STUDYING THE EFFECT OF ENVIRONMENTAL-FACTORS ON THE ENERGY-METABOLISM OF YEASTS

The yeast Debaryomyces hansenii, ubiquitous in marine environments and known to be highly osmotolerant, showed a higher efficency in coping with increased salinities in comparison to baker's and brewer's yeast Saccharomyces cerevisiae. Both yeasts changed their catabolic flows in response to increased salinities by producing glycerol, which partly explains the decreased growth yields at increased salinities. S.cerevisiae, on the other hand, demonstrated a higher efficiency at low pH values in comparison to D.hansenii. S.cerevisiae did not change its size-distribution of metabolic flows until a very low pH was reached, while D.hansenii showed higher heat yields and an increased arabinitol production in response to a more moderate decrease in pH. © 1990.