Physiological predisposition of various Clostridium species to synthetize 1,3-propanediol from glycerol

1,3-Propanediol (1,3-PD) production by fermentation of glycerol was first described in 1881 but little attention was paid to this biosynthesis for over a century. An increasing interest in microbial 1,3-PD production is observed since late 1980s. The high growth rate of the biofuel market and the perspective of glycerol becoming abundant attract even more attention to this valuable chemical. Glycerol conversion to 1,3-PD is known to occur in Clostridia, Enterobacteriaceae and Lactobacillaceae. Some clostridial species are among the best 1,3-PD producers. This work is a review of the current state of research on Clostridium spp. strains that ferment glycerol to 1,3-PD. It focuses on the metabolic pathways and factors that influence the production of this diol. The effects of different environmental stresses on the process of 1,3-PD synthesis are also covered. Moreover, various genetic engineering methods utilized in order to improve the capabilities of bacteria used in this process are presented. (C) 2012 Elsevier Ltd. All rights reserved.