Genetically Engineered Strains: Application and Advances for 1,3-Propanediol Production from Glycerol.

1,3-Propanediol (1,3-PD) is one of the most important chemicals widely used as monomers for synthesis of some commercially valuable products, including cosmetics, foods, lubricants and medicines. Although 1,3-PD can be synthesized both chemically and biosynthetically, the latter offers more merits over chemical approach as it is economically viable, environmentally friendly and easy to carry out. The biosynthesis of 1,3-PD can be done by transforming glycerol or other similar substrates using some bacteria, such as Clostridium butyricum and Klebsiella pneumoniae. However, these natural microorganisms pose some bottlenecks like low productivity and metabolite inhibition. To overcome these problems, recent research efforts have been focused more on the development of new strains by modifying the genome through different techniques, such as mutagenesis and genetic engineering. Genetically engineered strains obtained by various strategies cannot only gain higher yield than wild types, but also overcome some of the barriers in production by the latter. This review paper presents an overview on the recent advances in the technological approaches to develop genetically engineered microorganisms for efficient biosynthesis of 1,3-PD.