Fermentation strategies to improve propionic acid production with propionibacterium ssp.: a review

Abstract

Propionic acid (PA) is a carboxylic acid applied in a variety of processes, such as food and feed preservative, and as a chemical intermediate in the production of polymers, pesticides and drugs. PA production is predominantly performed by petrochemical routes, but environmental issues are making it necessary to use sustainable processes based on renewable materials. PA production by fermentation with the Propionibacterium genus is a promising option in this scenario, due to the ability of this genus to consume a variety of renewable carbon sources with higher productivity than other native microorganisms. However, Propionibacterium fermentation processes present important challenges that must be faced to make this route competitive, such as: a high fermentation time, product inhibition and low PA final titer, which increase the cost of product recovery. This article summarizes the state of the art regarding strategies to improve PA production by fermentation with the Propionibacterium genus. Firstly, strategies associated with environmental fermentation conditions and nutrition requirements are discussed. Subsequently, advantages and disadvantages of various strategies proposed to improve process performance (high cell concentration by immobilization or recycle, co-culture fermentation, genome shuffling, evolutive and metabolic engineering, and in situ recovery) are evaluated.

Keywords:

• Propionic fermentation
• fermentation strategies
• co-culture fermentation
• evolutive and metabolic engineering
• in situ recovery

Author contributions

KCC search for articles, construction of the tables, writing the manuscript, structuring the manuscript; ACC and JLI writing the manuscript, structuring the manuscript, revision of the manuscript. All the authors read and approved the final manuscript.

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

This work was financed by the Coordenação de Aperfeiçoamento de Pessoa de Nível Superior -Brasil (CAPES) -Finance Code 01 (process ([88887.463971/2019-00)]) and National Council for Scientific and Technological Development (process ([141130/2019-9]).