A MULTIPARAMETER APPROACH TO CONTROL THE GROWTH OF SACCHAROMYCES-CEREVISIAE IN LABORATORY MEDIA

The effects of combinations of reduced water activity (aw from 0.97 to 0.93), pH (3, 4, 5, and 6) and addition of potassium sorbate (0, 100, 500, and 1,000 ppm) on the growth of one strain of Saccharomyces cerevisiae in laboratory medium were studied. The minimal aw for growth inhibition in the absence of sorbate and in the range of optimal pH was 0.89. Various combinations of aw, pH and sorbate concentration prevented growth of the yeast at aw values above 0.89. For example, at v = 0.93, addition of 100 ppm sorbate at pH = 4.0 resulted in inhibition; at aw= 0.97 and same pH (4.0), 500 ppm of sorbate were necessary. The combined effects of the above parameters on generation time, maximum population, and lag time of the cells were also determined. Copyright © 1990, Wiley Blackwell. All rights reserved