Glucosamine content of tempe mould, Rhizopus oligosporus

The glucosamine content of Rhizopus oligosporus NRRL 2710 mycelium grown in different media was determined. In Sabouraud dextrose broth the glucosamin e content ranged from 51 g (kg dry biomass)(-1) for mycelial pellets less t han 5 mm diameter to 107 g kg(-1) for pellets 16-35 mm diameter. Mycelium g rown on Sabouraud dextrose agar contained 111 g glucosamine (kg dry biomass )(-1) while that grown on soymilk agar, used to simulate growth on soybeans in tempe, contained 82 g kg(-1). The estimation of glucosamine was reprodu cible, with a mean coefficient of variation of 4% for mycelial pellets and 11% for mycelium from agar media. It is suggested that a conversion factor of 12 g dry biomass (g glucosamine)(-1) is applicable to determine fungal b iomass in tempe fermentation. (C) 1999 Elsevier Science B.V. All rights res erved.