Heterologous 1,3-Propanediol Production Using Different Recombinant DSM 6423 Strains.

1,3-propanediol (1,3-PDO) is a valuable basic chemical, especially in the polymer industry to produce polytrimethylene terephthalate. Unfortunately, the production of 1,3-PDO mainly depends on petroleum products as precursors. Furthermore, the chemical routes have significant disadvantages, such as environmental issues. An alternative is the biobased fermentation of 1,3-PDO from cheap glycerol. DSM 6423 was originally reported to produce 1,3-PDO. However, this could not be confirmed, and a genome analysis revealed the loss of an essential gene. Thus, 1,3-PDO production was genetically reinstalled. Genes for 1,3-PDO production from DSM 525 and DSM 15410 (formerly ) were introduced into DSM 6423 to enable 1,3-PDO production from glycerol. 1,3-PDO production by recombinant strains were investigated under different growth conditions. 1,3-PDO production was only observed for [pMTL83251_P_1,3-PDO.diolis], which harbors the genes of DSM 15410. By buffering the growth medium, production could be increased by 74%. Furthermore, the effect of four different promoters was analyzed. The use of the constitutive promoter from led to a 167% increase in 1,3-PDO production compared to the initial recombinant approach.