Studies on the Fermentation Conditions and Anti-tumor Effect of Exopolysaccharide from Rhizobium sp.N613 / 微生物学通报

ABSTRACT

The potential of Rhizobium sp. N613 to produce the exopolysaccharide (REPS) was studied in this paper. Using an orthogonal design in a flask-shaker culture system, the fermentation medium and conditions of synthesizing REPS were optimized. Based on these results, the fermentation kinetic parameters were obtained in the batch fermentation with a 10L fermentor. The REPS yield of 11.31g/L was achieved by metabolic regulation during 40 h fed-batch fermentation. Transplanted tumor models of sarcoma 180 in mice were used to evaluate the anti-tumor effect. The result of anti-tumor activities showed that inhibition rate was 53.40%, when dose of REPS was 5mg/kg. These results indicate that REPS has the following properties the short duration of fermentation, the high yield, the low cost, the effective immunocompetence and thickening. Thus, REPS has the value of development and application.