초록
<P><B>Abstract</B></P> <P>The cellulolytic <I>Clostridium cellulovorans</I> has been engineered to produce <I>n</I>-butanol from low-value lignocellulosic biomass by consolidated bioprocessing (CBP). The objective of this study was to establish a robust cellulosic biobutanol production process using a metabolically engineered <I>C. cellulovorans</I>. First, various methods for the pretreatment of four different corn-based residues, including corn cob, corn husk, corn fiber, and corn bran, were investigated. The results showed that better cell growth and a higher concentration of <I>n</I>-butanol were produced from corn cob that was pretreated with sodium hydroxide. Second, the effects of different carbon sources (glucose, cellulose and corn cob), basal media and culture pH values on butanol production were evaluated in the fermentations performed in 2-L bioreactors to identify the optimal CBP conditions. Finally, the engineered <I>C. cellulovorans</I> produced butanol with final concentration >3g/L, yield >0.14g/g, and selectivity >3g/g from pretreated corn cob at pH 6.5 in CBP. This study showed that the fermentation process engineering of <I>C. cellulovorans</I> enabled a high butanol production directly from agricultural residues.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Robust cellulosic <I>n</I>-butanol production process by <I>C. cellulovorans</I> was developed. </LI> <LI> Pretreatment of four different corn-based residues was investigated. </LI> <LI> Effects of carbon sources, media and pH on butanol production were evaluated. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>