Effect of N-acetyl chito-oligosaccharides on the biosynthesis and properties of chitin in Saccharomyces cerevisiae

Chitin exists in yeast cells both as free and bound in a complex with beta-1,3/beta-1,6-glucan. The formation of covalent links between chitin and beta-glucans is catalyzed by the enzymes Crh1 and Crh2, acting as transglycosylases. We found that N-acetyl-chito-oligosaccharides, as well as laminarioligosaccharides, the respective products of partial hydrolysis of chitin, and beta-1,3-glucan, interfered with reactions catalyzed by Crh1p and Crh2p in vitro. However, the N-acetyl-chito-oligosaccharides did not influence the growth rate of the yeast, neither did they affect the yeast phenotype, but they prolonged the lag phase. Inhibition of Crh1 and Crh2 in vivo with oligosaccharides derived from chitin leads to an increase of alkali-soluble chitin and a decrease in the amount of chitin linked to beta-glucans. In addition, yeast cells growing in the presence of N-acetyl-d-chito-oligosaccharides accumulated more chitin than control cells.

Automated summary

Chitin exists in yeast cells both freely and bound to beta-glucan in a complex. Inhibition of Crh1 and Crh2 enzymes by N-acetyl-chito-oligosaccharides can increase alkali-soluble chitin, decrease chitin linked to beta-glucans, and prolong yeast lag phase.