Advances in the synthesis of biobutanol by consolidated bioprocessing from lignocellulose

Abstract

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.