Growth of Candida albicans on artificial D‐glucose derivatives

Abstract

Growth of Candida albicans on artificiaI D-gluCOSe derivatives (amino-, methyl-, acylglycosides and N-acetyl-D-glucosamine derivatives) was examined with the aim to find new inducers of the mycelial growth form. For representatives of particular groups (n-D-ghmopyranosylamine, Dglucose and N-acetyl-D-glucosamine) some physiological (growth, doubling time, specific growth rate, oxygen uptake and CO, production, respiration quotients), biochemical (dry weight yield, protein content, ethanol production), and morphological parameters (length-width quotient, volume, percentage of budding cells) of cultures in different growth phases were determined with regard to the type and concentration of carbon source. The results obtained may be valuable for studies of the structure-utilization relationships of carbohydrate derivatives as well as for the elucidation of yeast-myoelial transition in Candida albicans induced by unphysiological hexoses degradable intracellularly.Candida albimns is morphologically a pluripotent yeast-like microorganism growing under certain cultivation conditions in two habits (as budding and true hyphal cells).Despite intensive research by numerous laboratories (SIMONETTI et al. 1974, LAND et al. 1975, MITCHELL and SOLL 1979, SHEPHERD et al. 1980) definite knowledge about the mechanisms underlying this phenomenon has not been obtained.Recently, we have proposed (HRMOVA and DROBNICA 1981, 1982) that low intracellular glucose concentration may be sufficient in itself to govern the mycelial form of development. Based on this idea, we presume that the same effect, E.e. glucose limitation at the cellular level might be induced by artifically modified unphysiological D-glucose derivatives which may be expected to act independently of the concentrations-used. D-glucose derivatives used (scheme 1) can be divided into three groups: (I) glycosylamines; (11) D-glucose and methyl-&-D-glucopyranosides; (111) 2-acetamido-2-deoxy-D-glucose and methyl 2-acetamido-2-deoxy-a, 6-D-glucopyranoside derivatives (0-, and N-acetyl), or benzyl-oxycarbonyl derivatives. It should be noted there that carbohydrate derivatives are reasonably stable in aqueous solution a t 28 "C, except aldoses with free hemiacetal groups and glycosylamines which may undergo anomerization, or other covalent conformational changes, especially in contact with biological receptors (e.g. mannan-protein complex of yeast cell wall).The purpose of this report is twofold: (1) to describe physiological and morphological parameters of C. albicans grown on natural and artificially modified D-glucose derivatives; (2) to direct attention to new inducers of yeast-mycelial transition.