Combination of Statistical Techniques for Submerged Fermentation for Extracellular Polysaccharide and Biomass of Ganoderma tsugae

Abstract

Biomass and extracellular polysaccharide of Ganoderma tsugae have various biological activity including anti-inflamatory activity, antioxidant activity and antitumor activity. However, the growth rate of G. tsugae in nature is very slow. Therefore, many studies have attempted to develop mass culture systems for G. tsugae using laboratory techniques. Many parameters of submerged fermentation for G. tsugae were studies to determine the optimization of process by combination of statistical techniques. Ten parameters from preliminary results and literature reviews (maltose, skim milk, KH₂PO₄+K₂HPO₄, MgSO₄-7H₂O, CaCO₃, vitamin B₅+B₆, olive oil, ethanol, pH and shaking speed) were screened by Packett Berman design. The significant parameters were determined the optimal ranges by path of steepest ascent method. The optimal condition of process was performed by response surface method. Maltose, skim milk and pH are significant parameters for G. tsugae cultivation. The conditions of 31.031 g L^-1 maltose, 14.055 g L^-1 skim milk and an initial pH of 7.12 resulted in the maximum extracellular polysaccharide content of 415 mg L^-1 and the same fermentation broth at an initial pH of 6.46 exhibited the most biomass at 15.776 g L^-1. Finally, the optimal condition was compared with un-optimal condition which result indicates that the combination of statistical techniques enhance the productions of biomass and extracellular polysaccharide (13X and 1.5X of the control, respectively). Therefore, these strategies are useful for improvement of submerged fermentation of G. tsugae which it can apply in pharmaceutical industry.