Continuous in-situ extraction of acetic acid produced by Acetobacterium woodii during fermentation of hydrogen and carbon dioxide using Amberlite FPA53 ion exchange resins

Abstract

Ion-exchange resins have emerged as a promising technology for separation of targeted products from biochemical production. In this study, in-situ acetic acid extraction using Amberlite FPA53 resins was examined. The study includes initial testing of the resins for separation of different concentrations of acetic acid in water along with continuous in-situ extraction of acetic acid from gas-liquid fermentation with Acetobacterium woodi on a mixture of 70% H2–30% CO2. An average acetic acid adsorption of 67.6 mg/g resin was achieved using Amberlite FPA53, significantly lower than the concentration obtained with pure acetic acid solutions (159.6 mg/g resin). This result indicates that pH and competing components in the fermentation broth influence the efficiency of the resin. Implementing in-situ extraction of acetic acid increased its production by 1.6-fold resulting in 10.21 g/L acetic acid for extractive fermentation compared to 6.4 g/L for the control, without continuous extraction of acetic acid.