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

Area of Science:

• Biotechnology
• Metabolic Engineering
• Industrial Microbiology

Background:

• 1,3-propanediol (1,3-PDO) is a key chemical for polymers like polytrimethylene terephthalate.
• Current 1,3-PDO production relies on petroleum, posing environmental concerns.
• Biobased production from glycerol offers a sustainable alternative, but requires engineered microorganisms.

Purpose of the Study:

• To genetically re-engineer Clostridium beijerinckii DSM 6423 for 1,3-propanediol (1,3-PDO) production from glycerol.
• To optimize fermentation conditions and promoter elements for enhanced 1,3-PDO biosynthesis.
• To investigate the feasibility of using heterologous gene clusters for bio-PDO production.

Main Methods:

• Gene acquisition from Clostridium pasteurianum and Clostridium beijerinckii for 1,3-PDO pathway reconstruction.
• Introduction of these genes into a non-producing C. beijerinckii strain (DSM 6423).
• Fermentation experiments under varying conditions, including medium buffering and promoter analysis (e.g., thlA promoter).

Main Results:

• Successful reinstallation of 1,3-PDO production in a recombinant C. beijerinckii strain harboring genes from C. beijerinckii DSM 15410.
• A 74% increase in 1,3-PDO production achieved by buffering the growth medium.
• A 167% increase in 1,3-PDO production observed using the constitutive thlA promoter from Clostridium acetobutylicum.

Conclusions:

• Genetic engineering can restore lost metabolic pathways for valuable chemical production.
• Optimized fermentation and promoter selection are crucial for maximizing bio-PDO yields.
• This work demonstrates a viable strategy for sustainable, bio-based 1,3-PDO production.