A carbohydrate-degrading enzyme from Candida albicans: correlation between alpha-glucosidase activity and fungal growth.

Attempts to detect inducible carbohydrate-degrading enzymes from C. albicans were performed using carbohydrate-restricted media. Although alpha-amylase (polysaccharide hydrolase) was not induced from media containing starch or dextrin, alpha-glucosidase (disaccharide hydrolase) was induced from maltose-containing medium. alpha-Glucosidase activity was detected from the intact cells in suspension and from the supernatant of both spheroplasted and mechanically broken cells, but not from the media. Enzyme activity in intact cells was pH independent and increased during logarithmic growth phase and in media containing lower concentrations of maltose. The addition of 5 mM 1-deoxynojirimycin, a competitive inhibitor of alpha-glucosidase, suppressed fungal growth by more than 50%. These results suggest that alpha-glucosidase activity is crucial for fungal growth in medium containing maltose as a sole carbon source.