Biotechnological production of 1,3-propanediol from crude glycerol

1,3-Propanediol (1,3-PD) is one of the important products used in chemical industry, in particular for polyesters production (e.g. polyethers and polyurethanes). Using crude glycerol for producing 1,3-PD is a good solution from the economical as well as ecological point of view. Glycerol produced by cleavage of natural fats can be microbially converted to 1.3-propanediol by, among others, Citrobacter, Klebsiella, Lactobacillus, Enterobacter, and Clostridium strains. Biotechnological production of 1,3-PD from waste biomass is a promising and attractive alternative to the traditional chemical synthesis. The production of 1,3-PD by glycerol fermentation was already reported in 1881. The microbiological bioconversion pathway of glycerol to 1,3-PD has been known for long but the microorganisms taking part in this fermentation are not efficient. In addition, they are pathogenic. Consequently, natural producers of 1,3-PD are still being sought. In this review we present a historical outline of 1,3-PD production, as well as the microorganisms and their metabolic pathways that are involved in glycerol fermentation to 1,3-PD.