Optimization of Effect Factors for Mycelial Growth and Exopolysaccharide Production by Schizophyllum commune

Abstract

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.

Effects of Tween 80 and pH on mycelial pellets and exopolysaccharide production in liquid culture of a medicinal fungus

“…A more remarkable and desirable eVect of Tween 80 on the Cs-HK1 mycelial culture is the dramatic enhancement of EPS production. A few previous studies have also shown the stimulating eVect of Tween 80 on EPS production in submerged mycelial cultures of various fungi such as S. commune [4] and Botryosphaeria rhodina [15]. Some possible causes have been suggested, including the stimulation of biosynthetic activity for EPS production and the membrane permeability for EPS secretion, and the prevision of an alternative carbon source for EPS production [1,3].…”

“…Tween 80 (polysorbate 80) is one of the most favorable surfactants for EPS production by most microorganisms including medicinal fungi such as Grifola frondosa [5] and Schizophyllum commune [4]. In addition to their eVects on the growth and metabolite production, surfactants added to culture medium of fungal mycelia also inXuence the mycelial morphology.…”

Optimization of production of Microbial Exopolysaccharides (EPS) with essential oils from two medicinal plants

“…Essential oils extracted were sterilized by filtration (0.45 µm). Optimization of production of exopolysaccharides : Medium condition and other bacteria growth conditions are important factors for EPS production (Xu et al, 2003;Kaditzky and Vogel, 2008;Hao et al, 2010). This step is to vary successively each of the factors keeping the other constant.…”

Polysaccharide Production by Submerged Fermentation

“…Regarding the culture medium for polysaccharide production from fungi, different reports published in the last decade evidence the importance of the presence of vegetable oils rich in oleic acid as promoters of fungal biomass formation and, consequently, of their constituent polysaccharides (Yang et al 2000;Hsieh et al 2008;Hao et al 2010). When choosing the type of vegetable oil to be used as inductor of polysaccharide production, it is necessary to take into account the fatty acid composition of the oil since several researchers have reported that important amounts of linoleic acid suppress the production of biomass and polysaccharides, while the presence of oleic promotes their production (Park et al 2002;Hsieh et al 2006Hsieh et al , 2008.…”