乙偶姻和2,3-丁二醇是重要的生物基平台化合物，广泛应用于化工、食品等多个领域。但是，难以实现在一个菌株中选择性高产乙偶姻或2,3-丁二醇。本项目拟通过重构胞内氧化还原反应平衡途径，获得一株具有选择性高效合成乙偶姻和2,3-丁二醇性能的菌株。申请人前期在关键酶表达调控、产物合成与辅酶循环再生相关性论证与分析方面做了大量的研究。本申请研究内容涵括四个方面：（1）通过强化磷酸戊糖通路，拓宽葡萄糖代谢路径同时扰动胞内氧化还原平衡路径；（2）通过优化调控因子AlsR表达水平，使更多的丙酮酸流向2,3-丁二醇路径；（3）乙偶姻合成无需辅因子，通过IPTG诱导启动子引入或强化其它氧化还原反应平衡路径，定向强化乙偶姻合成；（4）对2,3-丁二醇脱氢酶进行辅酶偏好性改造，通过温度诱导启动子重构胞内氧化还原反应平衡途径，选择性强化2,3-丁二醇合成。最终实现乙偶姻和2,3-丁二醇在微生物体内可控合成。

Acetoin and 2,3-butanediol (2,3-BD) are bio-based important platform chemicals due to their wide industrial applications in chemical, food, and fuel, and other fields. It was reported that 2,3-BD could be reversely transformed to acetoin and it was difficult to selectively produce acetoin and 2,3-BD by a strain. Based on this finding, in this work, we will aim to engineer a Bacillus amyloliquefaciens through reconstruction the oxidation-reduction cycle to selectively produce acetoin and 2,3-BD. we have a wealth of experience in enzyme expression and cofactor metabolic engineering. Firstly, we will try to enhance the flux of pentose phosphate pathway to improve the pyruvic acid production and change the oxidation-reduction cycle. Then, redistribution the carbon flux to 2,3-BD pathway by manipulating AlsR expression level. Subsequently, acetoin production can be selectively enhanced by reconstruction of NADH/NAD+ regeneration cycle. Finally, 2,3-BD production can be selectively enhanced by change the cofactor preference to reconstruct the oxidation-reduction cycle.