Production of mycelial biomass and exo-polymer by Hericium erinaceus CZ-2: Optimization of nutrients levels using response surface methodology

Abstract

The Doehlert experimental design was used to optimize the production of mycelial biomass and exopolymer from Hericium erinaceus CZ-2 in this study. Statistical analysis showed that the linear and quadric terms of 3 variables: corn flour, yeast extract, and corn steep liquor had significant effects. The optimized combination of these 3 variables was confirmed through validation experiments. The optimal conditions for higher production of mycelial biomass (19.92 g/L) were estimated when the media composition concentrations were set as: 30.85 g/L, corn flour; 2.81 g/L, yeast extract; 16.9 mL/L, corn steep liquor; 10 g/L, glucose; 1 g/L, KH2PO4; and 0.5 g/L, MgSO4·7H2O; while a maximal exo-polymer yield (1.653 g/L) could be achieved when setting concentrations of: 32.71 g/L, corn flour; 2.35 g/L, Yeast extract; 14.42 mL/L, Corn steep liquor; 10 g/L, glucose; 1 g/L, KH2PO4; and 0.5 g/L, MgSO4·7H2O. The upscale production was also investigated using a 15 L fermentor using the optimized medium.