Differences in the carbohydrate composition between the yeastlike and mycelial cells of Mucor hiemalis

Abstract

The use of sporangiospores from a 20-day culture for inoculation enabled us to obtain yeastlike cells of strain Mucor hiemalis F-1431 (for which capacity for dimorphic growth was not previously studied) by cultivation in liquid medium under aerobic conditions. The carbohydrate composition of the fat-free biomass of the mycelial and yeastlike forms grown in the same culture under aerobic conditions was studied. In the fat-free biomass consisting of yeastlike cells, as compared to the mycelium, the contents of chitin and glucose decreased from 25 and 30.9% of dry biomass to 14 and 17.5% of dry biomass, respectively. We failed to detect any changes in the contents of fucose, galactose, mannose, and uronic acids among the heteropolysaccharide monomers of fungal cells of different morphotypes, which is probably due to the aerobic cultivation conditions. It was suggested that the composition of heteropolysaccharide monomers does not play such a significant role in the formation of yeastlike cells in the culture grown under aerobic conditions as the content of chitin, the main supporting biopolymer.