Optimization Of Submerged Culture Conditions For Mycelia Production In C. Gunnii And The Effect Of Polysaccharide On Immunosuppressive Factors From Tumor

The key influence factors in submerged fermentation for increasing mycelia biomass of Paecilomyces gunnii 5-19 (teleomorph is Cordyceps gunnii) were optimized by means of SAS software system. The optimum formulation of liquid fermentation medium of P. gunnii 5-19 was glucose (4.48%), peptone (1.67%), KH₂PO₄(0.5%), K₂HPO₄·3H₂O (0.5%). MgSO₄·7H₂O (0.5%). The optimum culture conditions of P. gunnii 5-19 was temperature (26°C), rotation rate (196r/min), pH6.9, inoculation amount (5%), inoculums ages (48h) and culture time (12 6hours). Mycelial DW was 14.34g/L. Four typical growth phases in the course of liquid fermentation were shown in 5L fermentor.The Crude polysaccharide was obtained from the cultured mycelia of P. gunnii 5-19 by extraction with hot water and precipitated by alcohol. The protein in it was removed by Sevage method, a special constituent CG-1 was isolated and purified by DEAE-52 chromatography. Its homogeneity was verified by UV scaning which was approved .To investigate the effect of mycelia polysaccharide from P. gunnii 5-19 (MPPG) on the immunosuppression property of tumor cell line S180 culture supernatant. The inhibitor effects of the culture supernatant of S180 cells in the presence or absence of MPPG on the LPS induced murine splenocyte proliferation and the killer activities were detected by MTT colorimetry. The level of transforming growth factor betal (TGFβ1) of the culture supernatant was measured by ELISA. The culture supernatant of S180 cells could strongly inhibit immunity in terms of the murine splenocyte proliferation, the killer activities and the TGFβ1 level, while MPPG could reverse the immunosuppression. MPPG can offset the immunosuppression of the supernatant from S180 cell culture and can reduce the TGFβ1 secretion by S180 cells.