基于一体化生物加工过程的木质纤维素合成生物丁醇的研究进展

一体化生物加工过程 (Consolidated bioprocessing，CBP) 是在一个生物反应器中完成水解酶生产、酶解、微生物发酵等多步生物过程的工艺。因其过程步骤简单、成本低，被认为是生产二代生物燃料最具发展前景的工艺。然而，由于木质纤维素降解与丁醇合成路径的复杂性，鲜有天然微生物可以直接利用木质纤维素合成丁醇。随着合成生物学技术的发展，在纤维素降解梭菌中引入丁醇合成途径，可以使单菌利用木质纤维素直接合成丁醇。但是该策略存在菌株代谢负荷重、丁醇产量低等问题。而混菌策略可以通过不同菌株的劳动分工，使单菌代谢负担得到缓解，因此进一步提高了丁醇合成效率。文中从单菌策略和混菌策略分析了近年来一体化生物加工过程利用木质纤维素合成丁醇的相关研究进展，为生物丁醇以及其他生物燃料的一体化生物加工过程研究提供借鉴。

Advances in the synthesis of biobutanol by consolidated bioprocessing from lignocellulose

Consolidated bioprocessing (CBP) is a multi-step process in a bioreactor, which completes hydrolase production, enzymatic hydrolysis, and microbial fermentation. It is considered to be the most promising process for the production of second-generation biofuels because of its simple steps and low cost. Due to the complexity of lignocellulose degradation and the butanol synthesis pathway, few wild microorganisms can directly utilize lignocellulose to synthesize butanol. With the development of synthetic biology, single-bacterium directly synthesizes butanol using lignocellulose by introducing a butanol synthesis pathway in the cellulolytic Clostridium. However, there are still some problems such as heavy metabolic load of single bacterium and low butanol yield. Co-culture can relieve the metabolic burden of single bacterium through the division of labor in different strains and can further improve the efficiency of butanol synthesis. This review analyzes the recent research progress in the synthesis of biobutanol using lignocellulose by consolidated bioprocessing from both the single-bacterium strategy and co-culture strategy, to provide a reference for the research of butanol and other biofuels.