초록
<P><B>Abstract</B></P> <P>Corn starch is the traditional substrate for butanol production by <I>Clostridium acetobutylicum</I>. However, the production suffers the problems of high substrate price and low sugar utilization yield. Waste <I>P.pastoris</I> semi-solid enriches with carbohydrate/protein and could be potentially used as an alternative substrate. In this study, NaOH was used to treat the waste semi-solid into suspensions. The fermentations were implemented by largely reducing initial starch content, and then adding the suspensions into broth after fermentations entered solventogenesis phase. Using the mixed substrate, final butanol concentrations in a 7 L anaerobic fermentor could reach and stabilize around 9.5–10.5 g/L, which was equivalent to that using 15% pure corn-starch; total sugar utilization yield largely increased from 50% to more than 90%, as disaccharides/trisaccharides were effectively utilized; 53% carbohydrate in the semi-solid was effectively digested which was beneficial for waste amount reduction; 57% expensive corn-starch could be saved.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel corn/waste <I>P. pastoris</I> solid mixed substrate based ABE fermentation. </LI> <LI> Total sugar utilization yield largely increased from 50% to over 90%. </LI> <LI> 53% utilization yield of carbohydrate in waste solid by gasification/liquefaction. </LI> <LI> 57% expensive corn-starch raw material saving. </LI> <LI> ABE concentration equivalent to that using 15% pure corn-starch achieved. </LI> </UL> </P>