(435b) Direct Conversion of Hemicellulosic Materials to Biobutanol

Being the most abundant biomass, lignocellulosic materials exhibited great potential to be utilized for biochemical production.  To shed light on the direct conversion of lignocellulosic biomass into biochemicals, here a newly discovered Clostridium sp. strain G117 was investigated on its capability to generate butanol with xylan as the sole carbon source.  In this study, 0.86 ± 0.07 g/L butanol accompanied with hydrogen were directly produced from xylan (30 g/L) by strain G117 without prior enzymatic hydrolysis.  After fermentation process optimization, 1.24 ± 0.37g/L butanol was obtained when fed with same amount of xylan within 5 days.  Noteworthy, in contrast to the traditional ABE fermentation process, acetone production by strain G117 was significantly suppressed when grown on xylan, which could greatly simplify the downstream separation process.  Moreover, much higher amount of butanol (2.94 g/L) was produced from xylo-oligosaccharides.  In summary, Clostridium sp. stain G117 is a promising candidate in degradation of the sustainable feedstock - xylan and its oligosaccharides to produce considerable amount of butanol without formation of by-products such as ethanol and acetone.  This study opens the door for direct conversion of lignocellulosic biomass to biochemicals in a single step with the elimination of fermentation by-products.