The Effect of Carbon Dioxide on Fruiting and on the Degradation of a Cell-wall Glucan in Schizophyllum commune

Abstract

A concentration of 5% CO2 in air prevents fruiting in S. commune and at the same time prevents the breakdown of R-glucan [(1 .fwdarw. 3)-.beta.,(1 .fwdarw. 6)-.beta.-glucan] in the wall which normally occurs during growth of the pilei. R-glucanase is produced as in cultures grown in air but cultures grown in CO2-enriched air form more of a water-soluble (1 .fwdarw. 3)-.beta.,(1 .fwdarw. 6)-.beta.-glucan (mucilage) and less R-glucan. This R-glucan is more resistant to enzymic hydrolysis which may explain the decreased breakdown of R-glucan in vivo. Since R-glucan degradation is required for growth of the pilei to occur, CO2 must indirectly inhibit growth of the pilei by changing the composition of the walls in the previously formed mycelium.