초록
<P>In this study, an efficient acetone-butanol-ethanol (ABE) fermentation strategy integrating <I>Clostridium acetobutylicum</I>/<I>Saccharomyces cerevisiae</I> co-culturing system with exogenous butyrate addition, was proposed and experimentally conducted. In solventogenic phase, by adding 0.2 g-DCW/L-broth viable <I>S</I>. <I>cerevisiae</I> cells and 4.0 g/L-broth concentrated butyrate solution into <I>C</I>. <I>acetobutylicum</I> culture broth, final butanol concentration and butanol/acetone ratio in a 7 L anaerobic fermentor reached the highest levels of 15.74 g/L and 2.83 respectively, with the increments of 35% and 43% as compared with those of control. Theoretical and experimental analysis revealed that, the proposed strategy could, 1) extensively induce secretion of amino acids particularly lysine, which are favorable for both <I>C</I>. <I>acetobutylicum</I> survival and butanol synthesis under high butanol concentration environment; 2) enhance the utilization ability of <I>C</I>. <I>acetobutylicum</I> on glucose and over-produce intracellular NADH for butanol synthesis in <I>C</I>. <I>acetobutylicum</I> metabolism simultaneously; 3) direct most of extra consumed glucose into butanol synthesis route. The synergetic actions of effective amino acids assimilation, high rates of substrate consumption and NADH regeneration yielded highest butanol concentration and butanol ratio in <I>C</I>. <I>acetobutylicum</I> under this stress environment. The proposed method supplies an alternative way to improve ABE fermentation performance by traditional fermentation technology.</P>