Abstract: We constructed an engineered Escherichia coli strain that can efficiently convert glycerol to acetol in our lab，the productivity of 1，2- Propanediol（1，2-PDO）may increase significantly if the strain can convert acetol to 1，2-PDO under aerobic condition. A mutant strain named PDO1 was screened from original strain E. coli BW25113ΔglpK，which metabolized glycerol aerobically. The further experiments showed that the strain PDO1 converted acetol to 1，2-PDO with the yield of 0.73 g/L and conversion rate of 0.493 g/g acetol under aerobic condition. The activity of glycerol dehydrogenase and the proportion of NADH were 75.6 and 1.64 times higher than that of control respectively. It is inferred that the increase of glycerol dehydrogenase activity and NADH level resulted in the mutant strain PDO1 metabolizing glycerol by glycerol dehydrogenase under aerobic condition and the conversion of acetol to 1，2-PDO .

Key words: Escherichia coli, 1, 2-Propanediol（1, 2-PDO）, glycerol, acetol, resting cells fermentation