高活力木聚糖酶菌株的筛选、酶学性质及酶解应用

Screening of Strain with High-Level of Xylanase, Enzymatic Characters and Hydrolysis Application

实验分离鉴定了高产木聚糖酶曲霉菌株,研究其固态发酵产酶条件及酶学性质。经菌落形态观察、ITS基因序列分析菌株在系统分类中的地位。通过单因素固态发酵实验确定其最佳产酶条件。结果表明,高产木聚糖酶曲霉菌株鉴定为黑曲霉(Aspergillus niger)。其最佳产酶条件为:玉米芯与麸皮比例为1∶3、氮源为尿素、初始pH为3.5、料水比为1∶3.5和接种量为10.0%。在此条件下发酵120h,木聚糖酶酶活最高可达10446.92IU/g。酶学性质研究表明,在pH为5.0、温度为45℃条件下木聚糖酶处于最优条件。糠醛(23.0g/L)和5-羟甲基糠醛(25.7g/L)对木聚糖酶的激活率分别达到15.9%和18.4%。Aspergillus niger SM751可以作为木聚糖酶潜在的生产菌株用于木质纤维素的酶解领域。

Xylanase producing fungi was isolated and identified,and its optimum condition for solid state fermentation and enzymatic properties were studied.The genealogical classification was analyzed by observation of colony morphology and ITS gene sequence.The optimal xylanase-producing conditions were assayed by single factor experiments.The results indicated that the isolated strain with high yielding xylanase was identified as Aspergillus niger.Its optimum xylanase activity was 10 446.92 IU/g under conditions as follows:1:3 as the ratio between corncob and wheat bran,urea as nitrogen source,5.0 as initial pH,1:3.5 as ratio between solid and liquid,10.0%as inoculum size.Study of xylanase charateristics showed that enzymatic activity were the optimum at pH of 5.0 and temperature of 45oC.Addition of furfural(23.0 g/L)or hydroxymethylfurfural(25.7 g/L)plays an activating effect with an increase of 15.9%and 18.4%,respectively.Therefore,Aspergillus niger SM751 could to be a promising microorganism for the production of xylanase,which could be used in the field of enzymatic hydrolysis of lignocellulose.