Response surface methodology was used to optimize 1,3-propanediol production by a novel recombinant Escherichia coli JM109 (pHsh-dhaB-yqhD). The optimal fermentation parameters for enhanced 1,3-propanediol yield were found to be: glycerol 61.8 g L-1, yeast extract 6.2 g L-1, Vitamin B12 0.049 g L-1 and fermentation time 30 h. Subsequent experimental trials confirmed the validity of the model. These optimal fermentation conditions in the cultivation flask culture led to a 1,3-propanediol concentration of 43.1 g L-1 and a conversion rate of 69.7% (g g(-1)). A maximum 1,3-propanediol concentration of 41.1 g L-1 was achieved in a 5 L-1 fermenter using the optimized parameters. (c) 2006 Society of Chemical Industry.