Short-chain acids as fermentation feedstock

Industrial biotechnology is a key technology in achieving net zero and circular economy goals. One method is through the use of fermentation to produce valuable products, whether it is bio-based chemicals and materials, or food. For fermentation to be a truly valuable technology, “waste-based” feedstocks need to be used. However, utilisation of organic waste complicates the fermentation process requiring extensive pre-treatment or the use of very specific, non-standard microorganisms which increases the cost of the process and complicates the strain development required to produce the desired product.

Currently, organic waste is typically treated by anaerobic digestion to produce carbon dioxide and methane, both of which contribute to the increasing greenhouse gas problem. Recently, there has been a growing trend in anaerobic fermentation (the first half of the anaerobic digestion process) to produce a short-chain acid mixture. The biggest problem is recovery and purification of these acids, and if they cannot be separated what can they be used for? [1]. This project looks at the feasibility of using these acids as a feedstock for pure-culture fermentation. This facilitates the production of bio-based chemicals and materials from waste sources, providing a route to simplification of the strain and process development. This project will investigate what potential microorganisms can be used, the microbial limitations of using these acids as a feedstock and fermentation methods/processes to overcome these biological limitations.