Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA.
Renewable Product Technology Research Unit, Agricultural Research Service, National Center for Agricultural Utilization Research, U.S. Department of Agriculture, Peoria, IL 61604, USA.
Bioresour Technol. 2014 Aug;165:314-8. doi: 10.1016/j.biortech.2014.03.112. Epub 2014 Mar 31.
A gene encoding a GH10 endo-xylanase from Geobacillus sp. WSUCF1 was cloned and expressed in Escherichia coli. Recombinant endo-xylanase (37kDa) exhibited high specific activity of 461.0U/mg of protein. Endo-xylanase was optimally active on birchwood xylan at 70°C and pH 6.5. The endo-xylanase was found to be highly thermostable at 50 and 60°C, retaining 82% and 50% of its original activity, respectively, after 60h. High xylan conversions (92%) were obtained with oat-spelt xylan hydrolysis. Higher glucan and xylan conversions were obtained on AFEX-treated corn stover with an enzyme cocktail containing WSUCF1 endo-xylanase (71% and 47%) as compared to enzyme cocktail containing commercial fungal endo-xylanase (64% and 41%). High specific activity, active at high pH's, wide substrate specificity, and higher hydrolytic activity on recalcitrant lignocellulose, make this endo-xylanase a suitable candidate for biofuel and bioprocess industries.
从地芽孢杆菌 WSUCF1 中克隆并在大肠杆菌中表达了编码 GH10 内切木聚糖酶的基因。重组内切木聚糖酶（37kDa）表现出 461.0U/mg 蛋白的高比活。内切木聚糖酶在桦木木聚糖上的最适活性为 70°C 和 pH6.5。该内切木聚糖酶在 50°C 和 60°C 下具有很高的热稳定性，分别在 60h 后保留其原始活性的 82%和 50%。燕麦-斯佩尔特木聚糖水解得到高木聚糖转化率（92%）。与含有商业真菌内切木聚糖酶的酶混合物（64%和 41%）相比，含有 WSUCF1 内切木聚糖酶的酶混合物（71%和 47%）在 AFEX 处理的玉米秸秆上获得更高的葡聚糖和木聚糖转化率。高比活、在高 pH 值下具有活性、广泛的底物特异性以及对难处理的木质纤维素具有更高的水解活性，使这种内切木聚糖酶成为生物燃料和生物加工行业的合适候选物。
