里氏木霉表达异源中性内切纤维素酶蛋白以改善最佳酶活pH

Highly efficient expression of neutral endoglucanases in Trichoderma reesei to improve cellulolytic pH profile

为了提高里氏木霉中天然纤维素酶的最佳活性pH,本实验从特异腐质霉,灰腐质霉的变种,枯草芽孢杆菌LH中分别筛选并克隆了其含有的中性纤维素酶基因,将其置于里氏木霉cbh1启动子的启动下,在里氏木霉中进行异源表达。改造株在pH 6.0下酶活提升16%,pH 7.0下活性保留75%以上,而此时原始菌酶活残留20%。本实验所得的产中性纤维素酶里氏木霉基因改造株,由于其良好的中酸性活性表现,在食品,纺织,纸浆和造纸行业应也有良好的使用潜力。

In order to improve the cellulolytic pH profile of Trichoderma reesei, neutral endoglucanase genes from Humicola insolens, Humicola grisea var. thermoidea and Bacillus subtilis LH were cloned and expressed under the control of the cbhl promoter. Transformants were obtained and exhibited the endoglucanase activity with 16% increase at pH 6.0, as compared to that of the parent strain, RUT C30. Additionally, the endoglucanase activity of NE2 at pH 7.0 was more than 75% , while 20% of the parent strain＇s endogenous endoglucanase activity remained. Due to their fine performances, the recombinants could be potentially used in neutral endoglucanases production for applications to food, textile, pulp and paper industries.