锁掷孢酵母产胞外多糖发酵条件优化

为进一步提高酵母菌产酵母胞外多糖（EPS）的能力，该研究以近粉红锁掷孢酵母（Sporidiobolus pararoseus）PFY-Z1为出发菌株，筛选出其最适产糖发酵培养基，并以此为基础，联合应用单因素试验、Plackett-Burman（PB）试验和中心组合设计（CCD）试验，优化菌株产EPS的最佳发酵条件。结果表明，菌株最佳培养基配方为葡萄糖15 g/L，硫酸铵15 g/L，硫酸镁1.8 g/L，氯化钙0.28 g/L，磷酸氢二钾0.24 g/L，氯化钠0.6 g/L。菌株最佳培养条件为培养温度28 ℃、摇床转速210 r/min、接种量5%、装液量100 mL/250 mL、培养时间6 d，培养基初始pH值5.10条件下，EPS含量最高，为（4.60±0.13）g/L，是优化前的1.40倍。该研究为今后利用S. pararoseus PFY-Z1产胞外多糖奠定了基础，同时也为酵母菌EPS的工业化制备和生产提供了理论依据。

Optimization of fermentation conditions for exopolysaccharide from Sporidiobolus pararoseus

In order to further improve the exopolysaccharide-producing ability of yeast, using Sporidiobolus pararoseus PFY-Z1 as the starting strain, the fermentation medium that most suitable for exopolysaccharide production was screened. Based on this, combined with single factor experiments, Plackett-Burman (PB) experiments and central composite design (CCD) experiments, the optimal fermentation conditions for exopolysaccharide production by the strain were optimized. The results showed that the optimal fermentation medium formula was glucose 15 g/L, ammonium sulfate 15 g/L, magnesium sulfate 1.8 g/L, calcium chloride 0.28 g/L, dipotassium phosphate 0.24 g/L, and sodium chloride 0.6 g/L. The optimal culture condition for the strain was fermentation temperature 28 ℃, shaker speed 210 r/min, inoculum 5%, liquid volume 100 ml/250 ml, fermentation time 6 d, and initial pH 5.10. Under the conditions, the highest exopolysaccharide yield was (4.60±0.13) g/L, which was 1.40 times that of before optimization. The study laid the foundation for the future use of S. pararoseus PFY-Z1 for exopolysaccharide yield, and also provided a theoretical basis for the industrial preparation and production of yeast exopolysaccharide.