高活力纤维素酶菌株K11-2的选育及其固态发酵条件的研究

A STUDY ON MUTATION AND SELECTION OF CELLULASE PRODUCING STRAIN K11-2 AND CONDITIONS OF IT'S SOLID-STATE CULTIVATION

从废弃纸浆中分得一株康氏木霉(Trichoderma Koningii),经紫外线和亚硝基胍处理,用平皿滤纸溃解法进行初筛,以及抗代谢物阻遏的选育,获得一株高产纤维素酶的突变株K11-2。该菌在以蔗髓和麦麸为基质进行固态培养时,滤纸糖化酶活力和羧甲基纤维素酶活力分别可达42 IU/g和1000 IU/g。适宜的培养基为:蔗髓15％,麦麸7％,营养液78％。营养液组成:MgSO_4·7H_2O 0.03％,KH_2PO_40.1％,(NH_4)_2SO_40.6％,麦芽汁1％。FPA和CM Case的最适作用条件均为:pH4.4,温度60℃。酶在32℃下保温20小时,pH稳定范围是3.O—5.6;65℃保温80分钟,FPA剩余活力有23％;CMCase剩余活力有46％。

An active cellulase producing strain which was identified as Trichoderma koningii was isolated from wast pulp. After treatment with ultraviolet and NTG, a mutant K11-2 from high cellulase yield was obtained under selection of catabolite repression-resistant. When K11-2 was grown on the solid medium composed of bagasse pith and wheat bran, the sacchrifying cellulase activities of Kll-2 on filter paper and CMC are as high as 42IU/g amd 1000IU/g respectively.The optimal medium is consisted of 15% bagasse pith, 1% wheat bran and 78% nutrint solution. The solution contained 0.03% MgSO4·7H2O; 0.1% KH2PO4; 0.6% (NH4)2SO4 and 1% wort. The optimal pH and tempereture for FPA and CMCase are pH4.4 and 60℃- The enzyme is stable at pH 3.0-5.6, 32℃ for 20h. After incubating the enzyme complex at 65℃ for 80 min, 23% of FPA and 46% of CM Case remain vital.