康宁木霉液态发酵高产纤维素酶和木聚糖酶

Submerged Fermentation of Trichoderma Koningii for High-Yield Cellulase and Xylanase

对选育的一株康宁木霉(Trichoderma koningii)QF-02进行液态发酵生产纤维素酶和木聚糖酶.通过单因素实验和正交实验考察了碳源、起始pH值、培养时间等因素对产酶的影响.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产酶的良好碳源.优化后的培养基组成:40目稻草粉4 g、Mandels营养液100mL、起始pH值4.5;摇瓶培养144 h后所得3种酶的活力分别为:滤纸酶活1.49 FPU/mL、β-葡萄糖苷酶活0.39U/mL、木聚糖酶活174.10U/mL.文中还比较了自制复合酶和一种商品纤维素酶的糖化能力,发现在水解碱预处理稻草和天然稻草时,自制复合酶产生的总还原糖产量比商品纤维素酶分别提高了55%和40%,葡萄糖产量分别提高了33%和12%.

In this paper, strain Trichoderma Koningii QF-02 was cultivated in submerged state to produce cellulases and xylanase, and the effects of carbon source, initial pH value and cultivation time for the production of enzymes were investigated by single-factor and orthogonal experiments. The results show that （ 1 ） the variety and nature of carbon sources play an important role in the enzyme production; （2） rice straw is a good carbon source due to its high performance and low cost; （3） the optimal shake-flask culture conditions are： 4 g of straw powder; （40 meshes）, 100mL of Mandels solution and an initial pH value of 4. 5; and （4） after the cultivation in the optimal conditions for 144 h, the enzymatic activities of filter paper cellulase, β-glucosidase, and xylanase respectively reach 1.49FPU/mL, 0. 39U/mL, and 174. 10U/mL. Moreover, by comparing the saccharification ability of the compos- ite enzyme produced by Trichoderma Koningii with that of a commercial cellulase, it is found that, when using the produced enzyme to treat alkali-pretreated straw and natural straw, the yields of total reducing sugar respectively increase by 55% and 40% , and the yields of glucose respectively increase by 33% and 12%.