Production of 1,2-Propanediol and 1-Propanol by Corynebacterium glutamicum through Metabolic Pathway Engineering

Production of the chemical 1,2-propanediol and the potential biofuel 1-propanol still depends on petroleum. The bacterium Corynebacterium glutamicum has been discovered to be able to overproduce 1,2-propanediol through metabolic engineering. Furthermore, the bacterium has also been previously modified to produce ethanol and isobutanol. Bielefield University's Volker F. Wendisch presented in his study the improved production of 1,2-propanediol by C. glutamicum as well as production of the potential biofuel 1-propanol.

The yield of the C. glutamicum expressing the genes gldA and mgsA from Escherichia coli was improved by additional expression of alcohol dehydrogenase gene yqhD from E. coli. Deletion of genes hdpA and ldh prevented formation of glycerol and lactate as by-products and further improved the 1,2-propanediol yield.

For the 1-propanol production, the operon ppdABC from Klebsiella oxytoca encoding was expressed in the improved 1,2-propanediol producing strain, resulting in a strain producing as much as 12 mM of 1-propanol and up to 60 mM unconverted 1,2-propanediol.