康宁木霉液态发酵高产纤维素酶和木聚糖酶的研究

对选育的一株康宁木霉（Trichoderma koningii）QF-02进行了液态发酵生产纤维素酶和木聚糖酶的研究。实验结果表明：碳源的种类及性质是影响产酶的关键因素，价廉易得的天然稻草是其产酶的良好碳源。在培养基组成为40目稻草粉4g、Mandels营养液100mL、起始pH值4.8的优化培养条件下，摇瓶培养120h所得3种酶的平均活力分别为：滤纸酶活（FPA）1.43IU/mL, β-葡萄糖苷酶活0.36IU/mL, 木聚糖酶活176.8IU/mL。与商品纤维素酶制剂相比，在FPA载量相同(3FPU/g原料)的情况下，自制的复合酶在水解碱预处理稻草和天然稻草时，总还原糖产量比商品纤维素酶提高55%和40%，葡萄糖产量提高33%和12%。研究结果还表明木聚糖酶和纤维素酶具有协同酶解木质纤维素的作用。

Study on the Submerged Fermentation of Trichoderma Koningii for High-yield Cellulase & Xylanlase

The strain Trichoderma koningii QF-02 was cultivated in submerged state to produce cellulases and xylanlase. The experimental results showed that the nature of carbon source played an important role in the synthesis of enzymes and rice straw was chosen as carbon source because of its good performance and cheap cost. A series of factors affecting on the synthesis of enzymes was investigated and then the optimal shake-flask culture condition was set as follows: the medium was composed of 4g straw powder (with size of 40#) and 100mL Mandels solution, with an initial pH of 4.8 and cultivation for 120h. As a result, it was got that the enzymatic activity of filter paper cellulase, β-glucosidase and xylanase were 1.43 IU/mL, 0.36 IU/mL and 176.8 IU/mL, respectively. Several enzymatic hydrolysis experiments were designed to test the effectiveness of the composite enzyme. Comparing to the commercial enzyme, the composite enzyme could produce 55% and 40% more of total reducing sugar as well as 33% and 12% more of glucose for the substrates of alkali-pretreated straw and natural straw respectively at a same FPA loading (3FPU/g biomass). The results also showed that there was a synergistic effect between xylanase and cellulase in the enzymatic saccharification of lignocelluosic materials.