纤维素酶产生菌的筛选及产酶条件的研究

目的：从三峡地区丘陵地带采集样品中分离以稻草秸秆粉为碳源的产纤维素酶菌株．方法：以刚果红为显色剂，采用CMC—Na固体培养基初步筛选产酶的微生物，然后将透明圈直径与菌落直径比值较大的菌株分离纯化后，进行摇瓶复筛，最后经过单因素实验和正交实验优化该茵珠的产酶条件．结果：分离得到一株产纤维素酶活力较高的菌株（X3），经初步鉴定其为曲霉属，该菌株产纤维素酶的最佳条件为：培养温度28℃、培养时间72h、初始pH值6、装量为15mL／250mL三角瓶．在此条件下FPA酶活为2．413IU／mL、CMC酶活为2．406IU／mI—J3一葡萄糖苷酶活为10．633IU／mL，分别是菌株X3初始酶活的l_04倍、2．20倍和1．19倍．结论：通过产酶条件优化后，菌株X3各酶活分别提高．

Study of Screening of Cellulase-Producing Strain and Its Fermentation Productions

Isolating the cellulose-producing strain from hilly area in the Three Gorges region was studied, which can take straw stalk powder as carbon resource. Firstly, the strain with big transparent zones is gotten with congored agar medium. The strain is then screened in shake flasks. Finally, the optimal condition for fermentation was obtained through the single-factor tests and orthogonal tests. An extracellular cellulase - producing strain X3 was isolated, which close homology to Aspergillus. The optimal conditions of solid fer- mentation for eellulase production are as follows= the temperature of fermentation is 28 ~C ; the time of fer- mentation is 72 h; the initial pH is 6; and the filled content of flask is 15 mL /250 mL. Under those condi- tions, its enzyme activities toward FPA, CMCase and~-glucosidase reached 2. 413 IU/mL, 2. 406 IU/mL, 10. 633 IU/mL, which is 1.04 times, 2.20 times, 1.19 times as high as the initial enzyme activities, respective- ly. The enzyme activities are increased under the optimal conditions.