Recruiting Energy-Conserving Sucrose Utilization Pathways for Enhanced 2,3-Butanediol Production in Bacillus subtilis

To improve the utilization of sucrose for 2,3-butanediol (2,3-BD) production, four combinations of heterologous energy-conserving sucrose utilization pathways were introduced into Bacillus subtilis Δ tet strain (a derivative from B. subtilis 168) and B. subtilis FJ-1 strain (a new isolate in our lab). Results demonstrated that the combination of cscB (encoding sucrose permease) from Escherichia coli and gtfA (encoding sucrose phosphorylase) from Streptococcus mutans showed the most remarkable enhancement for the 2,3-BD production. With sucrose and sugar cane juice as substrate, respectively, the Δ tet -CEG strain ( B. subtilis Δ tet strain containing the energy-conserving sucrose utilization pathway as referred above) showed 36.5% and 24.7% increase in 2,3-BD production than the control Δ tet strain, and the FJ-1-CEG strain also produced 23.8% and 44.5% more 2,3-BD than the control FJ-1 strain. The metabolic engineering strategy demonstrated in this study can be extensively applied to other microorganisms for reinforced production of desirable biochemicals from sucrose. Meanwhile, the newly isolated FJ-1 strain is an interesting platform strain that can be further engineered for efficient 2,3-BD production.