Enhanced Production of 2,3-Butanediol in Recombinant Escherichia coli Using Response Regulator DR1558 Derived from Deinococcus radiodurans

2,3-Butanediol (2,3-BDO) is a promising bio-based chemical for its wide range of applications in industrial areas as synthetic rubber precursor, food additives, and cosmetics. In this study, Escherichia coli DH5α was metabolically engineered for enhanced production of 2,3-BDO by expressing Bacillus subtilis alsS, alsD, and ydjL genes encoding α-acetolactate synthase, α-acetolactate decarboxylase, and acetoin reductase/2,3 -butanediol dehydro¬genase, respectively, along with Deinococcus radiodurans dr1558 gene encoding a response regulator. When recombinant E. coli DH5α strain expressing only B. subtilis alsS, alsD, ydjL genes was cultured in LB medium containing 20 g/L glucose, 3.14 g/L of 2,3-BDO was produced. Additional expression of D. radiodurans dr1558 gene in E. coli DH5α expressing alsS, alsD, and ydjL genes resulted in the production of 7.81 g/L of 2,3-BDO under the same culture conditions, which is 2.5 fold higher than that produced by the strain without DR1558. Transcriptional analysis of E. coli DH5α expressing DR1558 suggested that the expression levels of the genes related to 2,3-BDO pathways were enhanced, while those of genes related to by-product pathways were suppressed, compared with control strain expressing only 2,3-BDO synthesis genes. These results strongly suggest that introduction of the stress tolerant response regulator DR1558 can modulate metabolic pathways to favor production of the target product.