SOME EFFECTS OF AERATION ON THE GROWTH AND METABOLISM OF SACCHAROMYCES CEREVISIAE IN CONTINUOUS CULTURE

Abstract

In continuous fermentation of a complex, synthetic medium by Saccharomyces cerevisiae, a steady state was maintained for prolonged periods in the absence of oxygen. Growth reached a maximum at a low rate of aeration and under these conditions ester formation was markedly inhibited. At higher levels of aeration growth was reduced, the cells formed chains and aggregated, the rate of fermentation decreased and large quantities of acetoin and acetaldehyde were produced. Under fully aerobic conditions, ethanol production continued to account for the major part of the glucose consumed. The amount of diacetyl produced was insignificant at all rates of aeration. The extent of growth and the nitrogen content of the yeast were inversely related.