Metabolic engineering of Enterobacter aerogenes to improve the production of 2,3-butanediol

The enhanced production of 2,3-butanediol was investigated using a metabolic engineering approach and optimized fermentation conditions. New engineered strains of Enterobacter aerogenes ATCC 29007 were developed by deleting the D-lactate dehydrogenase (ldhA), phosphate acetyltransferase (pta), malate dehydrogenase (mdh), and acetaldehyde dehydrogenase (acdh) genes to block the production of lactate, acetate, succinate, and ethanol, respectively. The resulting engineered strain E. aerogenes SUMI02 (Delta ldhA Delta pta) produced 36.5 g/L of 2,3-butanediol in flask cultivation, an amount 8.11 times greater than that of its wild type counterpart (4.5 g/L). In addition, the 2,3-butanediol production and productivity reached 38.24 g/L and 0.8 g/L/h, respectively, in the batch fermentation using a bioreactor.