BEHAVIOR OF CANDIDA-UTILIS DURING GROWTH IN RELATION TO MG-2-CANE MOLASSES( AND K+ CONCENTRATION IN SUGAR)

Magnesium and potassium ions are present in sugar cane molasses in a c oncentration of about 0.3% and 2.5%, respectively, which is high enoug h to support biomass production from Candida utilis. Culture broth wit h 40 g/l of total reducing substances supplemented by the addition of 1 ppm of Mg2+ leads to a higher yield (Y x/s) in batch fermentation ex periments. The subsequent addition of Mg2+ up to 10 ppm decreases the yield coefficient from 0.53 to 0.42 without affecting the growth rate. Fermentation media supplemented with 1 to 10 ppm of K+ decreased both the yield coefficient and the specific growth rate. A Mg/K ratio of a bout 0.1 seems to be optimal for yeast biomass propagation.