黑曲霉固体发酵产木聚糖酶的响应面优化设计和其酶学性质的研究.pdfVIP

农业生物技术学报，2010 年，第18 卷，第1 期，第52-60 页 Journal of Agricultural Biotechnology, 2010, Vol.18, No.1, 52-60 研究报告 A Letter 黑曲霉固体发酵产木聚糖酶的响应面优化设计及其酶学性质的研究 * 刘明启 关荣发 陈文伟 中国计量学院生命科学学院食品系, 杭州, 310018 * 通讯作者, tony_cjlu@ 摘 要 本研究采用响应面法的中心组合对影响黑曲霉(Aspergillus niger JL15) 固体发酵产木聚糖酶的条件进 行了优化。以橘皮粉为基质，补充碳源、氮源，以及含水量和发酵时间对木聚糖酶产量具有显著影响(P0.05)。 模拟二次多项式回归预测模型，并建立自变量与响应值的回归方程，获得各因素的最佳水平，即：甘油、硫酸 铵的添加量分别为4.2%和3.1% ，含水量为61% ，发酵时间为73.4 h ，木聚糖酶活性最大预测值达922.9 U/g 干发酵产物，验证值为917.7 U/g 干发酵产物，高出基础培养基酶活3.2 倍。酶学性质分析研究表明，黑曲 霉木聚糖酶(XylA) 的最适温度和最适pH 分别为55℃ 和pH 5.0 。XylA 的Km 和Vmax 值分别为9.24 mg/mL 和54.05 μmol/min/mL 。Mn2+ 、Zn2+ 和Mg2+ 对XylA 活性具有促进作用，而Fe3+ 和Cu2+ 对XylA 活性具有明显 抑制作用。HPLC 分析结果表明，XylA 的水解桦木木聚糖和麸皮不溶性木聚糖的产物均为木糖至木六糖，主 要产物为木三糖。 关键词 木聚糖酶, 响应面法, 优化, 水解, 木三糖 Optimization of Solid State Fermentation Conditions for Xylanase Produc- tion by Aspergillus niger Using Response Surface Methodology and the En- zymatic Properties Liu Mingqi * Guang Rongfa Chen Wenwei Department of Food Science, College of Life Science, China JiLiang University, Hangzhou, 310018 * Corresponding author, tony_cjlu@ DOI: 10.3969/j.issn.1674-7968.2010.01.009 Abstract The production of xylanase (XylA) by a newly isolated Aspergillus niger JL15 strain in solidstate fermen- tation (SSF) on orange peel was optimized by response surface methodology (RSM). Results revealed that four fac- tors of concentrations of added glycerin and ammonium sulfate, moisture content, fermentation time had signifi- cant effect on the XylA production (P0.05). The maximum xylanase activity (917.7 U/g dry fermentation product) obtained at 4.2% glycerin, 3.1% (NH ) SO by employing orange peel as the solid substrate, 61% moisture content 4 2 4 and 73.4 h fermentation, which was close to the predicted one (922.9 U/g), and was 3.2 times higher than that of the basic medium (218.5 U/g). The optimum temperature and pH for XylA activity were 55℃ and pH 5.0, respective- ly