Submerged fermentation of medicinal fungus cordyceps sinensis for production of biologically active mycelial biomass and exopolysaccharides

Abstract

Cordyceps (Ophiocordyceps) sinensis, the Chinese caterpillar fungus or Cordyceps in brief, is an important medicinal fungus in Chinese herbal medicine with a wide range of health benefits and bioactivities. Because wild C. sinensis fungus (in the form of insect caterpillar-fungal fruiting body complex) is very expensive and rare in nature, mycelial fermentation has become the main source of C. sinensis fungal materials. Liquid or submerged fermentation of fungal mycelia has been widely exploited for large-scale production of C. sinensis mycelium biomass and exopolysaccharides (EPS). This chapter will give a brief introduction of the biological characteristics of the C. sinensis fungus and its medicinal functions and applications, and then mainly review the conditions and characteristics of C. sinensis mycelial culture for the production of mycelial biomass and EPS in shake-flasks and stirred-tank fermenters. In addition to the relevant studies reported by other research groups, this chapter will summarize the major findings from the studies by our own group with the Cs-HK1 fungus, including the fluid transport properties and the process parameters from small laboratory to large-scale industrial fermenters, the problems in separation and recovery of mycelial biomass and EPS from the viscous fermentation liquid, and the isolation, purification and molecular properties of polysaccharides.