米曲霉耐热木聚糖酶纯化及酶学特性研究

对米曲霉原始发酵液中耐热木聚糖酶进行纯化和酶学特性研究，利用甘蔗渣为碳源培养米曲霉，通过超滤和阴离子交换柱两步纯化得到木聚糖酶XynH1，分子量35．402kDa，利用飞行时间质谱和SDS—PAGE分析，推断XynH1为XylanaseXynF1，分子量为35．402kDa。XynH1属于糖苷水解酶家族10，酶活为442．2IU／nag，最适pH和温度分别为pH6．0和65℃，80℃以下及pH4．0～10．5范围内较稳定。

Purification and characterization of a thermostable xylanase from Aspergillus oryzae

These studies were constituted of the investigation of the purification of a thermostable xylanase XynH1 using fermentation broth of Aspergillus oryzae, the broth of sugar cane bagasse fermentation of A. oryzae subjected to ultrafiltration and ion exchange chromatography. The xylanase XynH1 was purified. Time-of-flight mass spectrometry coupled with SDS-PAGE analysis revealed that XynH1 was identical to xylanase XynF1 with a molecular weight of 35. 402 kDa. Sequence analysis indicated that XynH1 belonged to glycosyl hydrolases family 10. The enzymatic activity of XynH1 was measured 442.2 IU/mg. XynH1 was optimally active at pH 6.0 and 65 ℃, displaying stability within pH 4.0--10.5 and at temperature below 80 ℃.