Optimization of effect factors for mycelial growth and exopolysaccharide production by Schizophyllum commune.

This paper is concerned with the optimization of effect factors for mycelial growth and exopolysaccharide production by Schizophyllum commune by one-factor-at-a-time and orthogonal methods. The one-factor-at-a-time method was adopted to investigate the effects of six different compounds (sodium carboxymethylcellulose, L: -glutamic acid, V(B1), naphthalene acetic acid, oleic acid, and Tween 80) on mycelial growth and exopolysaccharide production. Among these factors, oleic acid, V(B1) and Tween 80 were identified to be the most important factors. Subsequently, the concentration of oleic acid, V(B1) and Tween 80 were optimized using the orthogonal matrix method. The effects of the factors on the mycelial growth of S. commune were in the order of oleic acid > V(B1) > Tween 80, and those on exopolysaccharide production were in the same order. The optimal concentration for mycelia and exopolysaccharide were determined as oleic acid 0.1% (v/v), V(B1) 0.5 mg/L, and Tween 80 6 mg/L. The subsequent verification experiments confirmed the validity of the models. Under this optimized conditions in shake flask culture, the mycelial yield and exo-biopolymer production were 25.93 and 2.79 g/L, respectively, which were considerably higher than those obtained in the preliminary studies. The result was further confirmed in a 7-L fermentor experiments.