纤维素乙醇统合加工过程中的酵母多酶共展示体系研究进展

Research advances on yeast co-displaying multi-enzyme system in consolidated bioprocessing of cellulosic ethanol

摘要:

利用统合生物加工过程(Consolidated bioprocessing，CBP)生产纤维素乙醇是目前国内外的研究热点。CBP需要一种“集成化”微生物，既能生产水解木质纤维素的多种酶类又能利用水解木质纤维素产生的糖类发酵产乙醇。以酿酒酵母表面展示技术为依托，建立CBP菌株多酶共展示体系的研究主要分为以下两个方向：一是直接将纤维素酶展示在细胞表面，即非复合型纤维素酶体系；另一种是通过表面展示纤维小体(Cellulosome)将纤维素酶间接地锚定在细胞表面，即复合型纤维素酶体系，本文主要从以上两个方向阐述了近几年对于纤维素乙醇生物统合加工过程的研究进展。因纤维小体对纤维素的降解能力比非复合型纤维素酶体系更强，所以其在酿酒酵母细胞表面的组装研究受到越来越多的关注，为了更深入透彻地了解纤维小体的酵母展示技术，文中对纤维小体的结构与功能及其在纤维素乙醇发酵中的应用研究进行重点论述，并对该领域的发展方向进行展望。

Abstract:

Consolidated bioprocessing (CBP), combining cellulose production, saccharification, and fermentation into one step, has been proposed as the most efficient way to reduce the production cost of ethanol from cellulosic biomass. Based on Saccharomyces cerevisiae surface display technology, cellulases are displayed on the cell surface using two approaches (1) noncomplexed cellulases, (2) multicellulase complex (cellulosome). The assembly of cellulosome on Saccharomyces cerevisiae has becoming a new hot spot in cellulosic ethanol CBP research because of its high cellulose hydrolytic activity than noncomplexed cellulases. In this paper, the basic structure of cellulosome and their applications in cellulosic ethanol production are reviewed. Also, the prospects of this research field are given based on our analysis of the problems that still have not solved by the previous studies.