Factors affecting mycelial biomass and exopolysaccharide production in submerged cultivation of Antrodia cinnamomea using complex media

Submerged cultures were used to identify growth-limiting nutrients by Antrodia cinnamomea strains. The mycelial biomass and EPS production by A. cinnamomea BCRC 35396 were markedly higher than other A. cinnamomea strains. A relatively high C/N ratio was favorable for both the mycelial growth (5.41 g/l) and EPS production (0.55 g/l); the optimum ratio was 40. The glucose was available utilized preferentially for mycelial growth, rather than for EPS production. Flushing the culture medium with nitrogen had a stimulating effect on both mycelial growth and EPS production. In addition, peptone, yeast extract and malt extract appeared to be important and significant component for EPS production. Phosphate ion, magnesium ion and thiamine were probably not essential for mycelial growth. By optimizing the effects of additional nutrition, the results showed that 5% (w/v) glucose, 0.8% (w/v) peptone, 0.8% (w/v) yeast extract, 0.8% (w/v) malt extract, 0.03% (w/v) KH2PO4, 0.1% (w/v) MgSO4 · 7H2O and 0.1% (w/v) thiamine could lead to the maximum production of EPS (1.36 g/l).