Optimization of submerged cultivation conditions for extra- anf intracellular polysaccharide production by medicinal Ling Zhi or Reishi mushroom Ganoderma lucidum (W. Curt.:Fr.) P. Karst (Aphyllophoromycetidae)

Abstract

This study showed that cultivation conditions (medium composition, initial medium pH, aeration rate, inoculum density) affect biomass and polysaccharide production in Ganoderma lucidum strain HAI 447. The synthetic medium (pH 5.5) with maltose at the concentration of 65.0 g L-1, peptone of 0.2%, as well as in the presence of K, Na, and Mg at concentrations of 6.0, 3.0, and 2.0 mM, respectively, presented the best conditions for biomass (29.2 g L-1) and extra- and intracellular polysaccharide (2.9 mg mL(-1) and 73.3 mg g(-1), respectively) production in the analyzed strain. Constant aeration was optimal for biomass and extracellular polysaccharide production, whereas cultivation under stationary conditions was the best for intracellular polysaccharide production. A peak in biomass and polysaccharide production was observed at an inoculum density of 20.0 mL.