The Use of -Glucosides in Classifying Yeasts

Abstract

Standardized methods were developed for the study of B-glucosidases in order to determine whether such tests could be used for classification. An exhaustive study of the [beta]-glucosidase activity of 119 strains of yeast was undertaken, using aesculin, arbutin, salicin or cellobiose as substrates. Results indicated (1) that the ability to split the [beta]-glucosides is dependent on the kind of medium on which the organism is grown, and the results may also be affected by the techniques used for detecting B-glucosidase activity. (2) A yeast able to split one [beta]-glucoside will not necessarily hydrolyze all. (3) Yeasts appear to contain different [beta]-glucosideaes. (4) Most yeasts, when grown under suitable conditions, will hydrolyze aesculin. Difficulties in the use of B-glucosides for classification are discussed.