Optimization of Technique Conditions for Decolorization and Extract of Exopolysaccharide by Cordyceps jiangxiensis / 微生物学通报

ABSTRACT

The technique conditions of decolonization of fermentation broth were successively optimized using single factor assay and orthogonal layout method in Cordyceps jiangxiensis. The optimal condition of decolorization was investigated to be 3g/100mL active carbon, 5 min absorption time, pH5 of fermented broth and 25℃absorption temperature. Under the optimal condition, the maximum decolorization rate of fermented broth reached 89. 6% , simultaneously 10. 7% consuming rate of exopolysaccahride was minimum. Subsequently, the extract condition of exopolysaccharide of C. jiangxiensis was further optimized by orthogonal layout design. The maximum exopolysaccharide production was 0. 38 g/L under the optimal condition, i. e. firstly fermented filtrate decolorized and deproteined was concentrated to 1/7 of its total volume, secondly concentration broth was mixed with four times its volume of absolute ethanol and stirred vigorously, lastly precipitation of exopolysaccharide proceeded at 4℃for 16 hrs and the exopolysaccharide collected by centrifugal ion and dryness.