Acetoin production from lignocellulosic biomass hydrolysates with a modular metabolic engineering system in Bacillus subtilis

作者：Qiang Wang, Xian Zhang, Kexin Ren, Rumeng Han, Ruiqi Lu, Teng Bao, Xuewei Pan, Taowei Yang, Meijuan Xu, Zhiming Rao · 发表于：Biotechnology for Biofuels and Bioproducts · 年份：2022 · DOI：10.1186/s13068-022-02185-z · 被引用次数：21 · 研究领域：Microbial Metabolic Engineering and Bioproduction、Biofuel production and bioconversion、Enzyme Catalysis and Immobilization

BACKGROUND: Acetoin (AC) is a vital platform chemical widely used in food, pharmaceutical and chemical industries. With increasing concern over non-renewable resources and environmental issues, using low-cost biomass for acetoin production by microbial fermentation is undoubtedly a promising strategy. RESULTS: This work reduces the disadvantages of Bacillus subtilis during fermentation by regulating genes involved in spore formation and autolysis. Then, optimizing intracellular redox homeostasis through Rex protein mitigated the detrimental effects of NADH produced by the glycolytic metabolic pathway on the process of AC production. Subsequently, multiple pathways that compete with AC production are blocked to optimize carbon flux allocation. Finally, the population cell density-induced promoter was used to enhance the AC synthesis pathway. Fermentation was carried out in a 5-L bioreactor using bagasse lignocellulosic hydrolysate, resulting in a final titer of 64.3 g/L, which was 89.5% of the theoretical yield. CONCLUSIONS: provides an economical and efficient strategy for large-scale industrial production of acetoin.