Integration of succinic acid and ethanol production with potential application in a corn or barley biorefinery. Production of succinic acid from glucose by Escherichia coli strain AFP184 was studied in a batch fermentor. The bases used for pH control included NaOH, KOH, NH_4OH, and Na_2CO_3.

The yield of succinic acid(cas:110-15-6) without and with carbon dioxide supplied by an adjacent ethanol fermentor using either corn or barley as feedstock was examined. The carbon dioxide gas from the ethanol fermentor was sparged directly into the liquid media in the succinic acid(cas:110-15-6) fermentor without any pretreatment.

Without the CO_2 supplement, the highest succinic acid(cas:110-15-6) yield was observed with Na _2CO_3, followed by NH_4OH, and lowest with the other two bases. When the CO_2 produced in the ethanol fermentation was sparged into the media in the succinic acid(cas:110-15-6) fermentor, no improvement of succinic acid(cas:110-15-6) yield was observed with Na_2CO_3. However, several-fold increases in succinic acid yield were observed with the other bases, with NH_4OH giving the highest yield increase. The yield of succinic acid(cas:110-15-6) with CO_2 supplement from the ethanol fermentor when NH_4OH was used for pH control was equal to that obtained when Na _2CO_3 was used, with or without CO_2 supplementation.

The benefit of sparging CO_2 from ethanol fermentation on the yield of succinic acid(cas:110-15-6) demonstrated the feasibility of integration of succinic acid(cas:110-15-6) fermentation with ethanol fermentation in a biorefinery for production of fuels and industrial chemicals.