When compared with the parent FMME044, the mutant E-11 exhibited superiorfermentation performance as follows: (1) the mutant E-11 exhibited increased tolerance to high concen-tration of acetoin, and the specific growth rate was 265.2% higher than that of the parent FMME044 inmedium containing 80 g/L acetoin; (2) acetoin production by the mutant E-11 reached 71.5 g/L at 44 hwhen cultured in a 7-L fermentor with 173 g/L glucose,