Metabolic Engineering Of P. Freudenreichii For Enhanced Propionic Acid Production

Propionibacteria are widely used in industry for manufacturing of Swiss cheese, vitamin B12 and propionic acid. Little is known about their genetics and only few reports are available on their metabolic engineering. Most previous metabolic engineering work on propionibacteria aimed at improving the fermentative production of vitamin B12. Propionic acid is well known as food preservative and as an intermediate in many industrial processes. Currently, it is mainly produced from petrochemicals which are perishable and costly. Its fermentative production suffers from low yields, low productivity and byproducts formation. In this research, by engineering P. freudenreichii using heterologous gene from E. coli, the productivity and purity of propionate were enhanced with proper choice of the carbon source. To our best knowledge, this is the first such report and it could be a novel route to enhance propionate production from biomass using renewable feedstocks.