Proteolytic activity of saccharomyces cerevisiae as affected by cultural conditions. II. Effect of some nutritional requirements

ABSTRACT

Supplementation of the fermentation medium with different nitrogen and carbon sources and their effects on growth and proteinase production by S. cerevisiae was studied. Organic complex nitrogen compounds enhanced yeast growth and stimulated the process of proteinase production. Similarly, medium fortified with molasses produced the highest growth and proteinase yields. Effect of different concentrations of peptone as the best nitrogen source - on growth and proteinase production by the yeast cells was also studied. 0.5% was the optimum concentration of peptone at which maximum growth and proteinase production were yielded. Effect of different concentrations of molasses - as the best carbon source - was studied. 1.0% was the optimum concentration of molasses at which maximal biomass yield was gained. Increasing molasses concentration in the medium resulted in a concomitant decrease of the proteolytic activity of the organism