Beta-glucanases in the yeast Cryptococcus albidus var. aerius. Production and separation of beta-glucanases in asynchronous cultures

Abstract

beta-Glucanases were detected in cell-free extracts of the yeast Cryptococcus albidus var. aerius when grown on glucose as the sole carbon source. The production of beta-glucanases was followed in log-phase cells and stationary-phase cells; the maximal production of beta-(1 leads to 3) and beta-(1 leads to 6) glucanases takes place respectively in log-phase and stationary-phase cells. The results show that there are marked differences in the elution profiles on Sephadex G-50 of fractions containing beta-glucanase from cells grown for 12, 24, 48, 72, and 96 h. The possibility either of replacement changes in fractions containing beta-glucanase activity or of a different synthesis of each beta-glucanase during the growth of the yeast is discussed. The results suggest that all fractions containing beta-glucanases hydrolyze both beta-(1 leads to 3) and beta-(1 leads to 6) linkages. Evidence in support of the conclusion that a low molecular form of beta-glucanase has a molecular weight of 2100 +/- 100 is also shown.