Studies on Some Growth Factors of Yeasts

Abstract

The B-vitamin requirements of 163 strains of yeasts, belonging in 110 named spp. and vars., were detd. Among the 86 named kinds found to be heterotrophic for one or more vitamins, deficiencies occurred as follows: biotin, in 78; thiamin, in 33; pantothenic acid, in 30; inositol, in 15; nicotinic acid, in 13; pyridoxine, in 13. No deficiency for riboflavin has been observed thus far in yeasts. Growth curves of Kloeckera brevis in response to increasing doses of 6 B vitamins are presented, and the use of this yeast in assays for inositol is described.