红杆菌NBS58-1产胞外多糖发酵条件优化及其保湿性研究

为提高红杆菌（Rufibacter hautae）NBS58-1液态发酵产胞外多糖（EPS）量，以胞外多糖产量为评价指标，通过单因素及响应面试验对菌株NBS58-1发酵产胞外多糖条件进行优化，并对其胞外多糖的保湿性进行研究。结果表明，菌株NBS58-1最佳产糖条件为初始pH 7.5、温度23 ℃、蔗糖14.1 g/L、酵母浸粉1 g/L、可溶性淀粉0.5 g/L、K2HPO4·3H2O 0.3 g/L、MgSO4·7H2O 0.05 g/L及丙酮酸钠0.3 g/L，在此条件下EPS产量为138.85 mg/L，是优化前的3.08倍。保湿性研究结果表明，在相对湿度0%条件下，48 h内该胞外多糖的保湿率优于透明质酸与壳聚糖；在相对湿度43%和81%条件下，吸湿能力稍低于透明质酸，但高于壳聚糖。

Optimization of fermentation conditions and moisture retention of exopolysaccharide from Rufibacter hautae NBS58-1

In order to increase the production of extracellular polysaccharides (EPS) from Rufibacter hautae NBS58-1 by liquid-state fermentation, the EPS production conditions by R. hautae NBS58-1 was optimized by single factor and response surface methodology using EPS yield as evaluation index, and the moisture retention of EPS was studied. The results showed that the optimal production conditions of EPS from strain NBS58-1 were initial pH 7.5, temperature 23 ℃, sucrose 14.1 g/L, yeast extract 1 g/L, soluble starch 0.5 g/L, K2HPO4·3H2O 0.3 g/L, MgSO4·7H2O 0.05 g/L and sodium pyruvate 0.3 g/L. Under these conditions, the EPS yield was 138.85 mg/L, which was 3.08 times that of before optimization. The moisture retention results showed that under the condition of 0% relative humidity, the moisture retention rate of the EPS was better than that of hyaluronic acid and chitosan within 48 h. Under the conditions of relative humidity of 43% and 81%, the moisture absorption ability was slightly lower than that of hyaluronic acid, but higher than that of chitosan.