Modified E.coli Bacteria Produces Butyric Acid in Greater Concentrations
This genetically modified bacterial biocatalyst produces butyric acid at higher concentrations than previously possible in mineral salts medium without complex nutrients. Butyric acid and its derivatives are used in the food, perfume, chemical, and pharmaceutical industries. For example, it’s used in the preparation of various butyrate esters used as food and perfume additives. Butyric acid is also converted to butanol, which depending on the source of carbon is a renewable biofuel. Other applications of butyric acid include plastics production, octane enhancement, and it’s also implicated in improving intestinal health and having anti-inflammatory effects. Currently, industrial scale butyric acid is produced by oxidation of butyraldehyde derived from propylene obtained during refining of petroleum. Although this is an inexpensive pathway for production as long as oil prices remain low, there remains a need to develop cost-competitive production from renewable sources. Butyric acid production by fermentation mostly utilizes anaerobic bacteria and is a sustainable way of producing this chemical but generating much higher yields depends on improvement of butyrate-producing microbial biocatalysts.
Feed additives also contain butyrate due to its suggested medial properties, but bio-based butyric acid is more preferable than petroleum-based butyrate in this application.
Researchers at the University of Florida have developed a genetically modified strain of E. coli that efficiently converts simple sugars to butyric acid in a medium with only mineral salts and sugar without generating byproducts that reduce yield and complicate downstream processing.
Genetically modified bacteria that improve the production of butyric acid for use in the manufacture of renewable fuel, medications, and ester-based commodities
- Uses genes from anaerobic microorganisms to establish a butyrate metabolic pathway in E. coli, generating higher yields of butyric acid
- Produces butyric acid with low levels of contamination by other metabolic byproducts or medium components, reducing cost of manufacture
E.coli does not naturally produce butyric acid; to overcome this limitation, genes from microorganisms that produce butyric acid have been added to the E. coli genome. Typically, the process of converting simple sugars to butyric acid also produces other organic acid byproducts. However, this newly engineered microbial biocatalyst produces butyric acid as the primary product, maximizing the yield of butyric acid and minimizing the need to remove byproduct contaminants. Additionally, fermentations further improve the economics of the process when conducted in a mineral salts medium.