Differences in the uptake of glucose and glycerol by Tieghemiomyces parasiticus in axenic culture

Abstract

Tieghemiomyces parasiticus, a biotrophic haustorial mycoparasite, makes excellent axenic growth on a glycerol – casein hydrolysate medium, while growth on a glucose – casein hydrolysate medium is equivalent to that of a control medium containing only the nitrogen source. A comparison of 14C-glucose and 14C-glycerol uptake indicates these substrates enter this mycoparasite at significantly different rates. Incorporation of 14C-glucose is extremely slow and limited, while 14C-glycerol incorporation is very rapid. Excellent axenic growth of this mycoparasite occurs when a glucose – casein hydrolysate medium is supplemented with the surface-active agent Tween 80. These findings suggest that the inability of glucose to support growth results from the inability of this substrate to readily enter the vegetative hyphae of this mycoparasite when cultured axenically.