Growth and biomass production with enhanced β-glucan and dietary fibre contents of Ganoderma australe ATHUM 4345 in a batch-stirred tank bioreactor

In this study we maximized biomass production by the basidiomycete Ganoderma australe ATHUM 4345, a species of pharmaceutical interest as it is a valuable source of nutraceuticals, including dietary fibers and glucans. We used the Biolog FF MicroPlate to screen 95 different carbon sources for growth monitoring. The pattern of substrate catabolism forms a substrate assimilation fingerprint, which is useful in selecting components for media optimization of maximum biomass production. Response surface methodology, based on the central composite design was applied to explore the optimum concentrations of carbon and nitrogen sources of culture medium in shake flask cultures. When the improved culture medium was tested in a 20-L stirred tank bioreactor, using 13.7 g/L glucose and 30.0 g/L yeast extract, high biomass yields (10.1 +/- 0.4 g/L) and productivity of 0.09 g L-1 h(-1) were obtained. The yield coefficients for total glucan and dietary fibers on biomass formed were 94.82 +/- 6 and 341.15 +/- 12.3 mg/g mycelium dry weight, respectively.