NUTRIENT REQUIREMENTS AND GROWTH CONDITIONS FOR PRODUCTION OF LACTASE ENZYME BY SACCHAROMYCES FRAGILIS1

Abstract

Lactase enzyme was produced by Saccharomyces fragilis NRRL Y-1109 grown in deproteinized Cheddar cheese whey. Nutrients and growth conditions required for maximum lactase production were determined. Lactose concentration, sources of growth factors; temperature of incubation, and pH of the whey were the primary factors affecting lactase production. Increased levels of lactose in whey stimulated the yeast to produce higher levels of lactase activity per gram of dried yeast. Corn steep liquor was the best source of added growth factors. Yeast grown under optimum conditions, pH 4.0 to 4.7 and 28 C, yielded 175 units per gram of yeast and 1300 units per liter of whey.