tAcetoin production by Bacillus amyloliquefaciens was used as a model of product feedback to develop astrategy to enhance the production of acetoin. To enhance the resistance of B. amyloliquefaciens to ace-toin, an acetoin-tolerant mutant E-11 was screened by using adaptive evolution with acetoin stress asthe selection pressure. 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, and the acetoin concentration and productivityof the mutant E-11 were 39.6% and 14.4% higher than those of the parent FMME044, respectively; (3) theunsaturated fatty acid contents in the mutant E-11 were 64.8%, 37.8%, and 18.4% higher than those in theparent FMME044 when cultured in 0, 40, and 60 g/L acetoin, whereas the saturated fatty acid contentsin the mutant E-11 were 9.5%, 13.9%, and 14.1% lower than those in the parent FMME044, respectively.