Biochemical Studies on Walls Synthesized by Candida utilis Protoplasts

Abstract

SUMMARYProtoplasts of Candida utilis obtained by treatment with helicase built a new wall in a liquid medium. The spherical protoplast was converted to a tubular form which later changed to an ellipsoidal yeast. Walls isolated at different stages of regeneration were analysed. Glucan (42 to 48 %), mannan (25 to 31 %) and protein (8 to 9 %) were the main constituents of walls of normal and completely regenerated ellipsoidal forms. Walls of the tubular forms differed markedly by having a high content of chitin (12 to 18 %) and of protein (20 %); mannose was present only as traces. The glucan content was similar in normal, tubular and ellipsoidal regenerating yeasts. These results demonstrate that some modifications occur in the structural polysaccharides of the yeast wall which can be correlated with morphological changes in the reversion process. The significance of glucose, mannose and acetylglucosamine polymers is discussed in relation to the biosynthesis of regenerated walls.

Differences in microfibrils in the walls of Agaricus bisporus secondary mycelium

“…Preparations of the residual thin fibrils treated for 7 days with commercial chitinase showed almost complete removal when examined under the conditions described, indicating the chitinous nature of these fibrils. These results agree with the previous chemical characterization of such extracted fractions [8] and also the report [10] in which c~-glucan from Aspergillus niger and Polyporus betulinus and commercial chitin samples showed similar ultrastructure to these preparations.…”

“…Chemical characterization of the different fractions extracted from hyphal walls of another strain of A. bisporus has been recently carried out [8].…”

“…c~and fl-glucanases were assayed in 0.05 M citrateborate-phosphate buffer, pH 5.5 (1 mg/ml) for 3 h and 24 h respectively. Chitinase was assayed for 7 days as described elsewhere [8]. Two drops of toluene were added to these incubation mixtures to avoid bacterial growth.…”

Effects of Lysozyme and Chitinase on the Spherules of Coccidioides immitis In Vitro

“…Kamaya (10) reported that lysozyme was fungicidal for several species of Candida including C. albicans. Lysozyme was found to interfere with reversion of helicase-prepared protoplasts of C. utilis to complete cells (16). Schmidt (21) showed that lysozyme inhibited hyphal growth and induced degeneration of germ tubes or the release of cytoplasmic contents from conidia of Peronospora tabacina.…”