초록
<P><B>Highlights</B></P><P>► We show BioH<SUB>2</SUB> from glucose by <I>E. coli</I> in 30-day extractive fermentations (EF). ► <I>E. coli</I> grew with air on minimal media then made H<SUB>2</SUB> anaerobically without inducers. ► EF controls fermentation pH by selectively and efficiently removing organic acids. ► EF uncouples the fluid and biomass retention times with suspended cells. ► The eventual limitation for extractive biohydrogen fermentation is solventogenesis.</P> <P><B>Abstract</B></P><P>Electrodialysis, an electrochemical membrane technique, was found to prolong and enhance the production of biohydrogen and purified organic acids via the anaerobic fermentation of glucose by <I>Escherichia coli</I>. Through the design of a model electrodialysis medium using cationic buffer, pH was precisely controlled electrokinetically, i.e. by the regulated extraction of acidic products with coulombic efficiencies of organic acid recovery in the range 50–70% maintained over continuous 30-day experiments. Contrary to previous reports, <I>E. coli</I> produced H<SUB>2</SUB> after aerobic growth in minimal medium without inducers and with a mixture of organic acids dominated by butyrate. The selective separation of organic acids from fermentation provides a potential nitrogen-free carbon source for further biohydrogen production in a parallel photofermentation. A parallel study incorporated this fermentation system into an integrated biohydrogen refinery (IBR) for the conversion of organic waste to hydrogen and energy.</P>