Metabolic engineering for efficient microbial production of 2,3-butanediol

2,3-butanediol (2,3-BD), which is considered as an important microbial metabolite, has been widely used in many fields such as food, medicine, chemical, and so on. Microbial 2,3-BD production has a history of more than 100 years, but the low efficiency of microbial 2,3-BD accumulation has constrained its process in biological manufacturing industrialization. Optimization of microbial metabolic pathway with the theory and method of metabolic engineering is expected to solve this problem. The objective of this paper is to review the state-of-the-art strain transformation and construction strategies in microbial synthesis of 2,3-BD, including overexpressing genes encoding for key enzymes in the 2,3-BD metabolic pathway, knocking out the metabolic bypass way genes, and using the methods of cofactor engineering in redesigning and reasonable transformation of the natural strains' metabolic network. Besides that, the using of synthetic biology in constructing brand new 2,3-BD pathways in model strains, such as Escherichia coli, Saccharomyces cerevisiae and Cyanobacteria, in order to enhance the yield or chiral 2,3-BD production in microorganisms is also introduced in this review. Finally, the future research direction is prospected, and the guidelines to develop high-efficiency microbial cell factories by advanced synthetic biology methods to achieve the optimal allocation of the intracellular metabolic flow are also proposed.