一株耐NMMO纤维素酶菌株的筛选及发酵优化

在常规筛选方法的基础上，利用在富集培养基中加入10 g/L NMMO，从土壤中筛选获得一株耐NMMO的高活性纤维素酶菌株Galactomyces sp. CCZU11-1。经研究，最适产酶培养条件为：碳源为甘蔗渣（5 g/L），氮源为(NH4)2SO4（5 g/L），表面活性剂为Tween-80（8 g/L），培养温度为30 ℃，初始培养pH值为5.5。在此条件下菌株培养7天后，FPA及CMCase分别为13.5 IU/mL和24.6 IU/mL。在培养体系和反应体系中分别加入200 g/L NMMO，Galactomyces sp. CCZU11-1纤维素酶仍具有良好的活性，表明其具有较高的耐NMMO性能及应用前景。

Isolation of a NMMO-tolerant cellulase-producing strain and optimization of corresponding fermentation conditions

Based on the conventional screening methods，a NMMO-tolerant cellulase-producing strain Galactomyces sp. CCZU11-1 with high cellulase activity has been isolated from soil samples using enrichment culture media containing 10 g/L NMMO. The optimal culture condition has been found，under which strain CCZU11-1 was cultured for 7 days，and the activity of FPA and CMCase was 13.5 IU/mL and 24.6 IU/mL respectively，while the carbon source was the bagasse (5 g/L)，the nitrogen source was (NH4)2SO4 (5 g/L)，the initial culture pH was 5.5，the culture temperature was 30 ℃ and the additive was surfactant Tween-80 (8 g/L). To add 200 g/L NMMO in the culture and reaction system respectively，the cellulase from this strain Galactomyces sp. CCZU11-1 still had good activity， indicating that it had high NMMO-tolerant ability and potential application.