(152g) An Extractive Fermentation Process for Enhanced Acetate Production from Biomass

The production of acetate from lactose by a coculture of Lactococcus lactis and Clostridium formicoaceticum immobilized in a fibrous bed was studied. The homolactic bacterium converts lactose to lactate and the homoacetogen then converts lactate to acetate. The overall acetate yield from lactose is ~ 95%. The acetic acid produced by fermentation can be selectively recovered from the fermentation broth using an amine-based extraction process. An extractive fermentation process using hollow-fiber membrane extractor is developed to reduce end-product inhibition and to increase the reactor productivity. This new process would provide an economical method of acetate production from whey permeate, a byproduct from cheese manufacturing, which contains significant amount of lactose. The acetate product can be used as an environment-friendly deicer. In this paper, the effects of several process parameters, including pH, concentrations of substrate and product, and solvent concentration on fermentation kinetics and product separation were studied and will be presented.