Improved simultaneous production of mycelial biomass and polysaccharides by submerged culture of Hericium erinaceum: optimization using a central composite rotatable design (CCRD).

The aim of this study was to optimize the culture medium used for the mycelial growth and production of intracellular polysaccharides (IPS) and exopolysaccharides (EPS) in a submerged culture of Hericium erinaceum. Of the various factors examined, including carbon and nitrogen sources, vitamins, mineral elements, and initial pH, those that proved to have a significant effect were then tested using a 2(4) central composite rotatable design (CCRD). Under the optimal culture conditions, the maximal yield of biomass reached 14.24 +/- 0.45 g l(-1) and was 1.85-fold higher than in the basal medium. The kinetics of EPS biosynthesis in a bioreactor showed that although the highest yield of EPS (2.75 +/- 0.27 g l(-1)) could be obtained on day 8, the process of biosynthesizing high molecular weight polysaccharides proceeded until the depletion of the carbon source in the medium (after 14 days of cultivation). Our results could be very helpful in the large-scale production of bioactive polysaccharides from H. erinaceum.