Lysis of intact yeast cells and isolated cell walls by an inducible enzyme system of Arthrobacter GJM‐1

Abstract

AbstractBacterium Arthrobacter GJM‐1 known in the literature as a good producer of α‐mannanase was found to accumulate in the culture fluid lytic activities against viable yeast cells during growth on isolated cell walls or β‐glucan fractions of yeast. The accumulation of the lytic activities showed an inducible character. The lytic system produced in the medium containing baker's yeast cell walls was capable of complete solubilization of cell walls in vitro. The system lysed viable cells of a number of yeast species and induced their conversion to protoplasts in an osmotically stabilized medium. The lytic system showed different pH and temperature optima when viable cells or isolated cell walls were used as substrates. The pH optimum of the lysis of isolated cell walls was identical with pH optimum of β‐glucanase activities in the crude system. The results pointed out that in the lysis of intact cells, in addition to β‐glucanases, some other factor is involved. Substantial differences in the nature of the outer and the inner surface of cell walls of Saccharomyces cerevisiae were confirmed in this paper based on the different susceptibility to lysis of the cell walls in vivo and in vitro.