OPTIMIZATION OF FERMENTATION PROCESS FOR EXOPOLYSACCHARIDES(EPS) PRODUCTION BY Cordyceps militaris

Exopolysaccharide (EPS) was obtained from Cordyceps militaris by submerged fermentation. The fermentation experiment for EPS production by C.militaris shows that beet sugar and KNO 3 are the optimum C and N sources. The fermentation medium optimized by orthogonal tests of the flask fermentation contains beet sugar 6 % , KNO 3 0 2 % , K 2 HPO 4 0 04 % , MgSO 4? 7H 2 O 0 02 % , FeSO 4 0 004 % and yeas t extract 0 06 % . The optimum fermentation conditions are initial pH 7.0, 96h of the fermentation time, 6 % of inoculation volume, fermentation temperature 28 ℃ , cell growth 24 ? 28 ℃ and 100ml/500ml flask of fermentation volume. C.militaris produces EPS with the productivity of 5 4 g/L under the optimizited conditions, 69 % higher than that under the original conditions (3 2 g/L).