发酵法生产2,3-丁二醇和3-羟基丁酮是目前国内外食品与工业生物技术领域研究热点之一。课题组前期筛选获得一株环境安全高产2,3-丁二醇解淀粉芽孢杆菌，发现该菌发酵前期主要积累2,3-丁二醇，后期转变为积累前体物质3-羟基丁酮（World J Microbiol Biotechnol. 2011, 27:2785-2790）。为揭示发酵产物逆向转化现象，课题拟从微生物生理和代谢水平对可逆代谢机制进行深入研究，探索发酵过程理性调控策略。课题拟通过发酵各阶段氧化还原状态、细胞能荷水平等重要生理生化分析，以及代谢流和代谢关键酶分析，建立细胞各生理状态、细胞代谢网络与产物逆向转化过程的相互关系。在此基础上，采用生理调控手段和分子修饰手段，进行针对性产物代谢调控，并反馈产物逆向转化的形成机制。课题通过探索解淀粉芽孢杆菌产物可逆代谢的形成机制及其调控策略，将为微生物代谢工程的研究进一步开拓思路。

Nowadays, microbial production of 2,3-butanediol and 3-hydroxy-2-butanone is attracting more and more attentions due to that they have wide application in food and industrial biotechnology field. In our previous work, a GRAS strain Bacillus amyloliquefaciens B10-127, capable of producing 2,3-BD effectively, was isolated. When glucose was used as carbon source in fermentation, the fermentation characterizations of this strain were analyzed and a new phenomenon of reverse transforming 2,3-butanediol which was synthesized from glucose to acetoin was detected. Before 96 h, glucose which was mainly transformed to 2,3-butanediol and acetoin was totally consumed, while at the end of fermentation, the yield of acetoin was greatly improved but 2,3-butanediol was declined（World J Microbiol Biotechnol. 2011, 27:2785-2790）. To reveal the new phenomenon of reverse transforming 2,3-butanediol to acetoin at the end of fermentation, we will investigate substrate consumption, productions biosynthesis, key enzyme characteristics, and the strain's key physiological features such as level of energy charge and oxidation-reduction state at different fermentation stages. Based on these properties, we will try to regulate specific metabolites synthetize through altering the key physiological features of cells and modifying key genes. Consequently, the expected results the metabolic regulation of the new phenomenon of reverse transformation would provide techniques and references for other microbial metabolic engineering research.