木聚糖酶产生菌的筛选、发酵及酶学性质

该研究对木论自然保护区土壤中高产木聚糖酶的菌株进行了分离，经菌落形态观察、ITS基因序列分析对菌株进行了鉴定，并通过单因素固态发酵实验确定最佳产酶条件。结果表明，筛选到1株高产木聚糖酶菌株，并鉴定为黑曲霉（Aspergillus niger）。其最佳产酶培养基配方：玉米芯与麸皮质量比为1∶7、氮源为硫酸铵（添加量1.4 g/L）、初始pH值为5.0、料水比为1∶3.5（g∶mL），接种量为7.5%。在此优化条件下，木聚糖酶酶活最高可达10 801.3 IU/g。酶学性质研究表明，木聚糖酶的最适作用pH值为5.5、最适作用温度为37 ℃。

Screening,fermentation and enzymatic properties of xylanase-producing strain

The strains with high yield xylanase were isolated from the soil of Mulun nature reserve. After colony morphology observation and ITS gene sequence analysis, the isolated strains were identified, and the optimum condition of solid-state fermentation was also studied by single factor analysis. Results showed that a strain with high yield xylanase was isolated and identified as Aspergillus niger. The optimum culture conditions of the strain for xylanase yield were obtained as follows: corncob and wheat bran mass ratio 1∶7, ammonium sulfate (1.4 g/L addition) as nitrogen source, initial pH 6.0, solid-liquid ratio 1∶3.5 (g∶ml), and inoculum 7.5%. Under the optimal conditions, the xylanase activity was 10 801.3 IU/g. The results of enzymatic properties showed that the optimal pH and temperature of xylanase were 5.5 and 37 ℃, respectively.