黄曲霉产胞外β-1,3-1,4-葡聚糖酶的发酵条件优化

Optimization of Fermentation Conditions for β-1,3-1,4-Glucanase Production by Aspergillus flavus

研究发现一株高产β-1,3-1,4-葡聚糖酶的黄曲霉菌株,优化了其产酶条件并考察了粗酶潜在的工业应用价值。依次采用单因素法和响应面分析法优化该菌发酵产酶条件,得到其优化产酶条件:麸皮19 g/L、磷酸氢二铵30g/L、吐温-60 21 g/L、NaCl 5 g/L、MgSO_4·7H_2O 0. 5 g/L、KH_2PO_40. 75 g/L、培养基初始pH值8. 0、培养温度38℃、培养时间6d。在此条件下,黄曲霉能够分泌的最高胞外β-1, 3-1,4-葡聚糖酶酶活达155.9 U/mL。水解研究发现,该酶能高效降解大麦粉和燕麦粉中的β-葡聚糖,并直接生成葡萄糖。这些结果表明,黄曲霉能高效分泌β-1,3-1,4-葡聚糖酶,且该酶具有较强的工业应用前景。

An Aspergillus flavus with the ability to yield high production ofβ-1,3-1,4-glucanase was found.The fermentation conditions for this enzyme in the shake flask were optimized using a combination of one-single-factor method and response surface methodology.The results indicated that the optimal culture medium components forβ-1,3-1,4-glucanase production were 19 g/L wheat bran,30 g/L(NH 4)2 HPO 4,21 g/L Tween-60,5 g/L NaCl,0.5 g/L MgSO 4·7H 2 O and 0.75 g/L KH 2 PO 4 at an initial pH of 8.0.The highest enzyme activity of 155.9 U/mL was obtained when the strain was cultured at 38℃for 6 d in the optimized culture medium.The crudeβ-1,3-1,4-glucanase from Aspergillus flavus could hydrolyze oat and barley powder to mainly yield glucose.These results indicated that the extracellularβ-1,3-1,4-glucanase produced by Aspergillus flavus possess great potential for its industrial applications.