Wang Qiang, Zhang Xian, Ren Kexin, Han Rumeng, Lu Ruiqi, Bao Teng, Pan Xuewei, Yang Taowei, Xu Meijuan, Rao Zhiming
Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, 214122, People's Republic of China.
Department of Bioengineering, The University of Illinois at Urbana-Champaign, Urbana, IL, USA.
Biotechnol Biofuels Bioprod. 2022 Aug 24;15(1):87. doi: 10.1186/s13068-022-02185-z.
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.
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.
The recombinant strain BSMAY-4-P provides an economical and efficient strategy for large-scale industrial production of acetoin.
乙偶姻（AC）是一种重要的平台化合物，广泛应用于食品、制药和化工行业。随着对不可再生资源和环境问题的日益关注，利用低成本生物质通过微生物发酵生产乙偶姻无疑是一种有前景的策略。
本研究通过调控参与芽孢形成和自溶的基因，减少了枯草芽孢杆菌在发酵过程中的缺点。然后，通过Rex蛋白优化细胞内氧化还原稳态，减轻了糖酵解代谢途径产生的NADH对AC生产过程的不利影响。随后，阻断了与AC生产竞争的多条途径，以优化碳通量分配。最后，利用群体细胞密度诱导型启动子增强AC合成途径。使用甘蔗渣木质纤维素水解物在5-L生物反应器中进行发酵，最终产量为64.3 g/L，为理论产量的89.5%。
重组菌株BSMAY-4-P为乙偶姻的大规模工业化生产提供了一种经济高效的策略。
