Removal of Acetic Acid from Bacterial Culture Media by Adsorption onto a Two-Component Composite Polymer Gel

Abstract

Organic acids, including acetic acid, are the metabolic products of many microorganisms. Acetic acid is a target product useful in the fermentation process. However, acetic acid has an inhibitory effect on microorganisms and limits fermentation. Thus, it would be beneficial to recover the acid from the culture medium. However, conventional recovery processes are expensive and environmentally unfriendly. Here, we report the use of a two-component hydrogel to adsorb dissociated and undissociated acetic acid from the culture medium. The Langmuir model revealed the maximum adsorption amount to be 44.8 mg acetic acid/g of dry gel at neutral pH value. The adsorption capacity was similar to that of an ion-exchange resin. In addition, the hydrogel maintained its adsorption capability in a culture medium comprising complex components, whereas the ion-exchange did not adsorb in this medium. The adsorbed acetic acid was readily desorbed using a solution containing a high salt concentration. Thus, the recovered acetic acid can be utilized for subsequent processes, and the gel-treated fermentation broth can be reused for the next round of fermentation. Use of this hydrogel may prove to be a more sustainable downstream process to recover biosynthesized acetic acid.

Effect of culture medium composition on the growth and biopolyesters production by the marine bacterium Saccharophagus degradans

“…2), ya que se identificó al ácido acético como subproducto de la fermentación. Este compuesto puede resultar tóxico, afectando la fisiología de muchos microorganismos incluso en concentraciones tan bajas como 0.5 g/L (Kato et al, 2022). Existen varios reportes para diferentes bacterias en los que se produce ácido acético debido a una desviación del flujo de carbono, ya sea por condiciones de oxigenación inadecuadas o por el exceso de fuente de carbono.…”

The use of xylose from elephant grass liquor and coproduction of organic acids by wild‐type bacteria isolated from food waste

“…This organic acid can also be used as a raw material or intermediate in the production of compounds such as ethenyl ethanoate (vinyl acetate), benzenedicarboxylic acid (terephthalic acid), cellulose acetate, as well as a solvent 4,5 . The global demand for AA is 10 million tons per year, and by 2024 the world market for the production of this chemical input is expected to reach US$ 11.4 billion 5,6 . It is therefore important to have more sustainable alternatives for the manufacture of AA because its usual production requires a significant amount of carbon sources from fossil origin 5 .…”

“…AA is typically obtained from the carbonylation of methanol in industry, although approximately 10% of its production involves the biotechnological route and it is mainly used in the manufacture of vinegar due to the regulations in various countries regarding the use of this metabolic route in food condiments 7,8 . The production of AA from microbial fermentation is expected to increase due to the growing need to find methods of production with lower CO 2 emissions 6 …”

“…4,5 The global demand for AA is 10 million tons per year, and by 2024 the world market for the production of this chemical input is expected to reach US$ 11.4 billion. 5,6 It is therefore important to have more sustainable alternatives for the manufacture of AA because its usual production requires a significant amount of carbon sources from fossil origin. 5 AA is typically obtained from the carbonylation of methanol in industry, although approximately 10% of its production involves the biotechnological route and it is mainly used in the manufacture of vinegar due to the regulations in various countries regarding the use of this metabolic route in food condiments.…”

“…7,8 The production of AA from microbial fermentation is expected to increase due to the growing need to find methods of production with lower CO 2 emissions. 6 Approximately 90% of LA production comes from biotechnological industries, mainly using bacterial fermentation. 9 Around 70% of the production of this acid belongs to the food industry, especially the dairy sector, with yogurt being produced mainly from the co-fermentation of Streptococcus termophilus and Lactobacillus bulgaricus.…”