Complementary Action of Melibiase and Galactozymase on Raffinose Fermentation

Abstract

ON the basis of experimental investigations on the inheritance of hydrolytic and fermentative ability in yeasts, we have been led to the conclusion that an exact knowledge of the genotype of the organism employed is not only desirable but also necessary if the processes of hydrolysis and fermentation are to be studied in detail. Since the existence of six different genes (M ₁, M ₂, M ₃, M ₄, M ₅ and M ₆) responsible for the hydrolysis and subsequent fermentation of maltose has been demonstrated in yeasts (Winge and Roberts¹, Gilliland², and Winge and Roberts (unpublished work)), and since these genes are not biochemically identical—for example, M ₁ hydrolyses both maltose and sucrose and M ₂ hydrolyses maltose alone—it is necessary, through appropriate hybridizations and segregations, to isolate each gene individually in a single cultural type in order to investigate the activity of the enzyme synthesized by that particular gene. Otherwise, the presence of additional hydrolytic genes in the culture under investigation may well lead to a confused interpretation of the experimental results.