Cultivating conditions influence exopolysaccharide production by the edible Basidiomycete Antrodia cinnamomea in submerged culture

Antrodia cinnamomea is a medicinal fungus that has been used in Taiwan as a traditional medicine for the treatment of tumorigenic diseases. We prove that controlling the culturing conditions (i.e., temperature and pH) and modifying the composition of the medium (i.e., carbon, nitrogen, mineral sources and vitamins) can dramatically enhance the production of the exopolysaccharide of A. cinnamomea. We have found that the temperature, initial pH, and agitation time are all critical for exopolysaccharide production during the cultivation of A. cinnamomea in submerged cultures; our optimized conditions were 28 °C, pH 5.5, and 14 days, respectively. In addition, when optimizing the effects of additional nutrition, we found that 5% (v/v) glucose, 0.5% (v/v) calcium nitrate, 0.1% (v/v) ferrous sulfate, and 0.1% (v/v) nicotinic acid led to the greatest production of exopolysaccharides; the exopolysaccharide production, mycelial biomass and specific product yield reached 0.49 g/l, 2.60 g/l and 0.19 g/g, respectively. The results indicate that nutrients can be utilized to improve the production of exopolysaccharide and that good mycelial growth does not seem to be a determining factor for a high production yield of exopolysaccharide in A. cinnamomea.