Production of 1,3-Propanediol from Glucose by Recombinant Escherichia coli BL21(DE3)

Abstract

A range of recombinant strains of Escherichia coli were developed to produce 1,3-propanediol (1,3-PDO), an important C3 diol, from glucose. Two modules, the glycerol-producing pathway converting dihydroxyacetone phosphate to glycerol and the 1,3-PDO-producing pathway converting glycerol to 1,3-PDO, were introduced into E. coli. In addition, to avoid oxidative assimilation of the produced glycerol, glycerol oxidative pathway was deleted. Furthermore, to enhance the carbon flow to the Embden- Meyerhof-Parnas pathway, the Entner-Doudoroff pathway was disrupted by deleting 6-phosphogluconate dehydratase and 2-keto-3-deoxy-6-phosphogluconate aldolase. Finally, the acetate production pathway was removed to minimize the production of acetate, a major and toxic by-product. Flask experiments were carried out to examine the performance of the developed recombinant E. coli. The best strain could produce 1,3-PDO with a yield of 0.47 mol/mol glucose. Along with 1,3-PDO, glycerol was produced with a yield of 0.33 mol/mol glucose.