响应曲面法优化酵母β-葡聚糖酶解工艺及产物分析

Optimization of enzymolysis of yeast β-glucan by response surface method and analysis of hydrolyzed products

采用β-葡聚糖酶对酵母β-葡聚糖进行酶解,利用单因素和响应面实验,以水溶性酵母β-葡聚糖得率为指标优化酶解工艺,并对水溶性酵母β-葡聚糖与原酵母β-葡聚糖的结构和热稳定性进行了研究。最佳酶解条件:底物质量浓度1.14 g/100 mL,酶活浓度0.16 U/mL,温度44℃,pH 4.2,水溶性酵母β-葡聚糖得率为39.89%。红外光谱分析结果表明,水溶性酵母β-葡聚糖与原酵母β-葡聚糖的糖苷键型均为β构型,分子构象相同。热稳定性分析表明,水溶性酵母β-葡聚糖和原酵母β-葡聚糖的特征分解温度分别为356℃和360℃,终止分解温度分别为740℃和780℃,热稳定性差异不大。

Theβ-glucan was hydrolyzed byβ-glucanase.The single-factor and the response surface(RSM)test were used to optimize the enzymolysis process with the yield of water-soluble yeastβ-glucan as an index.The structure and thermal stability of water-soluble yeastβ-glucan were examined.The results showed that the optimum conditions were substrate concentration of 1.14 g/dL,enzyme activity of 0.16 U/mL,temperature of 44℃,pH value of 4.2.The highest yield of water-soluble yeastβ-glucan was 39.89%.The results of infrared spectroscopy showed that the glycosidic bond of water-soluble yeastβ-glucan and the original yeastβ-glucanwereβ-configuration,and their molecular conformation were the same.The thermostability analysis showed that the characteristic decomposition temperature of water-soluble yeastβ-glucan and yeastβ-glucan were 356℃and 360℃,respectively.The final decomposition temperature was 740℃and 780℃,respectively.The difference in thermal stability between the water-soluble yeastβ-glucan and the original yeastβ-glucan was not significant.