耐热黑曲霉3.316产外切葡聚糖苷酶培养基优化及酶学性质研究

以外切葡聚糖苷酶的酶活力为指标,对黑曲霉产外切葡聚糖苷酶的培养基组分进行优化,并研究外切葡聚糖苷酶酶学性质。单因素和响应面法对黑曲霉3.316产外切葡聚糖苷酶培养基条件优化结果表明,最佳培养基组分为:小麦秸秆14.73 g/500 mL,硫酸铵2.22 g/500 mL,微晶纤维素+麦芽糖2.18 g/500 mL,在该条件下外切葡聚糖苷酶2.120 U/mL,酶活力较未优化前相比提高了91%。外切葡聚糖苷酶最适温度是50 ℃。外切葡聚糖苷酶在50 ℃较稳定,相对酶活保持在98%~99%范围内。外切葡聚糖苷酶在pH为3.0、7.0时表现出较高的稳定性,相对酶活在70%以上。外切葡聚糖苷酶能够在Fe2+和表面活性剂的作用下促进酶活力,同时在高温及酸性环境中发挥作用,能够参与高效降解高温酸性环境中的纤维素,提高生产率,同时将分解成的葡萄糖供发酵使用,具有应用高温大曲发酵酒生产的潜力。

Optimization of Exoglycosidase Medium Produced by Aspergillus niger 3.316 and Its Enzymology Properties

The enzymatic activity of exoglucanase was used as an indicator. The medium components of exoglucanase produced by Aspergillus niger were optimized, and the enzymatic properties of exoglucanase were studied. The single factor and response surface method for the optimization of the conditions for exogenous dextranosidase production by Aspergillus niger 3.316 showed that the optimal medium components were:Wheat straw 14.73 g/500 mL, ammonium sulfate 2.22 g/500 mL, microcrystalline fiber and maltose 2.18 g/500 mL. Under there condition, the exoglucanase was 2.120 U/mL, and the enzyme activity was increased by 91% compared with that before optimization. The optimal temperature for exoglucanase was 50℃. Exoglucanase had higher thermal stability at 50℃. Exoglucanase exhibited higher stability at pH3.0 and 7.0. Exodextranosidase could play a role in high temperature and acid environment, participate in the efficient degradation of cellulose in high-temperature acidic environments, improve productivity, and use the decomposed glucose for fermentation at the same time, which would have the potential to apply high-temperature Daqu fermentation wine production.