木聚糖酶高产菌株的筛选及其产酶规律研究

The Selection of A High Xylanase Yielding Bacterium and Research on Its Enzyme Producing Regulation

本研究采用透明圈比较法,从质粒转化变异菌种资源中纯化出1个木聚糖酶高产菌株。同时,采用单因子和多因子相结合的方法及DNS法,对该菌株的适宜发酵条件和产酶规律及木聚糖酶活检测体系进行了初步研究。结果表明:该菌株在改良培养基中的对数生长期在1～7h之间,产酶高峰期在8h左右,发酵液酶活达到344U/ml;木聚糖酶活力检测采用0.1mol.L-1柠檬酸-柠檬酸钠缓冲液,pH值5.2～5.8,木聚糖浓度0.8%,温度60℃,DNS用量为2.0～2.5m l。

In present study, a strain of high xylanase yielding bacteria was screened and purified from plasmid transformed variation microorganisms by clear halo comparison method. Meanwhile, a preliminary investigation of the optimal fermentation condition, enzyme production regularity and detection system of the activity of xylanase of the bacteria was performed with single factor method, multiple factor combinative method and DNS method, respectively. The main results were as follow： The logarithmic phase of the bacteria were ranged from 1 h to 7h, the enzyme yielding climax stage and the enzyme activity in fermented substances of the bacteria was at 8h and 344 U/mL, respectively. The main parameters in the measurement of enzyme activity of the Xylanase were as following： 0. 1 mol·L^-1 of citric acid - sodium citrate buffer solution with pH value of 5.2 - 5.8, concentration of xylanase at 0. 8 %, temperature at 60℃ and the DNS application at 2.0 - 2.5 ml, respectively.