Fig. 4

The effect of acoR knock-out on acetoin metabolism of B. licheniformis. a Time course of the growth (squares) and acetoin consumption (triangles) by the acoR-disrupted strain (WX-02ΔacoR) (open symbols) and wild-type strain (WX-02) (solid symbols) in medium with acetoin (2.3 g/L) as the sole carbon source. b The accumulation of acetoin and 2,3-BD isomers by the mutant strain (WX-02ΔacoR) and wild-type strain (WX-02) (at 24-h of culture) in medium with glucose (120 g/L) as carbon source. The cells were grown under the shake-flask culture with minerals in 2,3-BD production medium were used for each cases. Data are means of three replicates, and error bars show standard deviations