The Manufacture of Glutaric Acid using Fermentation

Glutaric acid, also known as pentanedioic acid, is a widely used chemical for various applications. These include production of polyamides, polyurethanes, glutaric anhydride, 1,5-pentanediol, and 5-hydroxyvaleric acid (Li et al., 2020).

The manufacture of glutaric acid using fermentation involves the use of microorganisms, typically bacteria, to produce glutaric acid through a bioconversion process. Glutaric acid is a dicarboxylic acid with various industrial applications, including the production of polymers, plasticizers, and pharmaceuticals. Here’s an overview of the process:

1. Microorganism Selection: The first step is to select a suitable microorganism that has the ability to produce glutaric acid through fermentation. Bacteria of the genus Pseudomonas, especially Pseudomonas putida, are commonly used for this purpose due to their natural ability to produce glutaric acid.
2. Fermentation Medium Design: The fermentation medium is prepared, providing the necessary nutrients and carbon sources for the microorganism’s growth and glutaric acid production. Carbon sources such as glucose, sucrose, or other sugars are often used.
3. Inoculation: The selected microorganism is inoculated into the fermentation medium, typically in large-scale fermentation tanks (bioreactors). The fermentation process is carried out under controlled conditions, including temperature, pH, oxygen supply, and agitation.
4. Metabolic Pathway Engineering: To enhance glutaric acid production, metabolic pathway engineering may be employed. This involves manipulating the metabolic pathways within the microorganism to direct the metabolic flux towards glutaric acid synthesis, effectively increasing its production rate.
5. Fermentation and Growth: The microorganisms are allowed to grow and multiply in the bioreactor while continuously consuming the carbon source and producing glutaric acid as a metabolic byproduct.
6. Glutaric Acid Accumulation: As the fermentation progresses, glutaric acid accumulates in the fermentation broth. The concentration of glutaric acid in the broth increases over time.
7. Monitoring and Optimization: Throughout the fermentation process, various parameters are monitored, such as cell density, glutaric acid concentration, and pH levels. If necessary, adjustments to the fermentation conditions may be made to optimize glutaric acid production.
8. Harvesting and Recovery: Once the fermentation process is complete, the glutaric acid is recovered from the fermentation broth through various separation and purification techniques. These techniques may include filtration, centrifugation, crystallization, and chromatography.
9. Product Formulation: After purification, the glutaric acid is formulated into the desired product forms, such as powder or liquid, suitable for its intended applications.

The use of microbial fermentation for glutaric acid production offers a sustainable and cost-effective method to meet the demand for this important industrial chemical. Glutaric acid serves as a building block for the synthesis of various chemicals and materials, making it a valuable product in the chemical industry.

References

Li, G., Huang, D., Sui, X., Li, S., Huang, B., Zhang, X., … & Deng, Y. (2020). Advances in microbial production of medium-chain dicarboxylic acids for nylon materials. Reaction Chemistry & Engineering, 5(2), pp. 221-238 (Article)