Production of bioactive exopolysaccharides from bitter medicinal mushroom, Antrodia camphorata (M. Zang et C.H. Su) Sh.H. Wu et al. (Aphyllophoromycetideae) in submerged cultivation

Abstract

This study examines the effects of various fructose concentrations in media on the production and quality of bioactive exopolysaccharides (EPS) from Bitter medicinal mushroom, Antrodia camphorata in submerged cultures. The fructose in media of submerged cultures of A. camphorata significantly affected the production, average molecular weight (Mn), and antioxidant activity of exopolysaccharides. The specific growth rate decreased monotonically from 0.33 to 0.25 1/day as the fructose concentration increased from 10 to 60 g/L; however, maximum production and productivity for EPS increased from 75.23 to 164.87 mg/L and 6.27 to 9.70 mg/L/day, respectively. In addition, the fed-batch culture used in this study significantly improved the production of EPS (2.43-fold enhancement, from 75.23 to 182.99 mg/L), number average molecular weights of EPS (1.47-fold enhancement, from 5.44 x 10, to 7.98 x 10(5) Da), protein/exopolysaccharide ratios (1.63-fold enhancement, from 16% to 26%), and antioxidant activity of EPS (1.32-fold enhancement, from 60% to 79%), as compared with corresponding properties of batch fermentation at 10 g/L fructose in an air-lift bioreactor. The antioxidant activity of EPS was highly correlated with number average molecular weights (R2 = 0.90) and protein/exopolysaccharide ratios (R2 = 0.96). The positive results of this research have successfully verified the promotion efficiency on the production and quality of EPS from the medicinal mushroom A. camphorata.