植物乳杆菌YM-2菌株胞外多糖生物合成工艺优化

对从云南传统发酵豆豉分离得到的植物乳杆菌YM-2(Lactobacillus plantarum YM-2)菌株胞外多糖(exopolysaccharide,EPS)生物合成条件进行优化。首先对培养基成分中的碳源、氮源种类进行筛选;然后利用单因素试验分析碳源含量、氮源含量、培养时间以及培养温度对EPS产量的影响;最后采用Box-Behnken法进行四因素三水平响应面分析以确定其最优工艺条件。结果表明,植物乳杆菌YM-2菌株生物合成EPS最佳条件为碳源(葡萄糖)含量30 g/L、氮源(酵母粉)含量30 g/L、培养时间30.05 h、培养温度36.36℃,在此工艺条件下,植物乳杆菌YM-2 EPS产量为257.362 mg/L。

Optimization of Biosynthesis Conditions for the Production of Exopolysaccharides by Lactobacillus plantarum YM-2

The fermentation conditions for the production of exopolysaccharides (EPS) by Lactobacillus plantarum YM-2,isolated from traditional fermented tempeh in Yunnan province, were optimized. Firstly, the carbon and nitrogen sourcesin the medium were screened. Secondly, the effects of carbon source concentration, nitrogen source concentration, culturetime and culture temperature on EPS yield were studied through one-factor-at-a-time analysis. Finally, response surfacemethodology (RSM) based on a four-variable, three-level Box-Behnken design was used to determine the optimal cultureconditions as follows: carbon source concentration, 30 g/L; nitrogen source concentration, 30 g/L; culture time, 30.05 h; andculture temperature, 36.36 ℃. Under these conditions, the yield of EPS was 257.362 mg/L.