Clostridium cellulolyticum is a kind of medium-temperature-facultative anaerobic bacteria in non-ruminant that can degrade crystalline cellulose effectively by secreting cellulosome multienzyme complex. Cellulosome contains the scaffoldin CipC which can mostly combine eight enzyme molecules. The N-end of CipC consists of carbohydrate-binding module (CBM),eight highly homologous cohesins and two hydrophilic X2 modules. The all enzyme components of the cellulosome complex possess a special docking protein module that can bind specifically with the CipC cohesin. The genes coding CipC protein and nine cellulose-degradation-related enzyme are all in a big gene cluster up to 26 kb. In recent years,the researches of cellulosome from Clostridium cellulolyticum are deepening. Artificial cellulosome has been successfully designed,constructed,turned in and expressed in Saccharomyces cerevisiae. By reforming metabolic networks of the existing engineering strains, the bio-refinery yield can be improved as well as the cost reduced.%解纤维梭菌(Clostridium cellulol yticum)是一种非反刍类中温兼性厌氧细菌,能够分泌纤维小体多酶复合物,对结晶纤维素具有高效的降解能力.纤维小体均含有最多可以结合8个酶分子的脚手架蛋白CipC,CipC的N端是由碳水化合物结合模块、8个高度同源的粘连模块和2个亲水性的X2模块组成.纤维小体复合物的所有酶组分都含有一个特殊的对接蛋白模块,能够特异性地与CipC粘连蛋白相结合.编码CipC蛋白以及9个与纤维素降解相关酶类的基因都在一个高达26 kb的大基因簇上.近年来,解纤维梭菌纤维小体的相关研究不断深入,已成功设计、构建人工纤维小体,并且成功在酿酒酵母中转入、表达纤维小体.通过对现有工程菌株的代谢网络改造,可以提高生物炼制的产率、降低生产成本.
展开▼
