Bioconversion of organosolv-treated bamboo into biobutanol integrated with on-site hydrolytic enzyme production

The aim of this study is to convert organosolv-treated bamboo into biobutanol hydrolyzed by lignocellulosic enzyme mixtures produced on site through solid state fermentation (SSF). Higher xylanase and β-xylosidase activity in crude hydrolytic enzyme mixtures produced from untreated bamboo under SSF contributed to a higher saccharification yield (76.1%) than commercial ones (67.3%). The modified organosolv pretreatment under mild conditions, without acid catalysts at 35 °C, could also improve the sugar yield from bamboo efficiently by reducing 29.8% of lignin content. Finally, in situ extraction using biodiesel as the extractant could improve the final butanol titer to 28.4 g L⁻¹ with a yield of 0.24 g g⁻¹ from the organosolv treated bamboo enzymatic hydrolysate, thus demonstrating the first investigation of biobutanol production from bamboo. The results suggested that a crude cellulase complex produced under SSF and organosolv pretreatment could efficiently provide bamboo hydrolysate for biobutanol production without commercial cellulase usage. This has potential for large-scale biobutanol production from bamboo wastes.