초록
<P><B>Abstract</B></P> <P>Dilute acid pretreatment of biomass generates enormous amount of hydrolysate (rich in inhibitors and pentose sugars), that remains unutilized for bioethanol production due to inadequacy of efficient C<SUB>5</SUB>-fermenting organisms. In this study, a predominantly pentose fermenting extremely thermophilic bacterium strain DBT-IOC-X2, pertaining to the genus <I>Thermoanaerobacter</I> was isolated from Himalayan hot spring. Batch experiments indicated substantial inhibitor resistance (2 g dm<SUP>−3</SUP> for furfural, 5-HMF, and acetic acid), substrate tolerance (∼15 g dm<SUP>−3</SUP>), co-sugar fermentation ability (co-production ethanol yield of 0.29 g/g), and high ethanol yield (83.57% and 91.12% of the theoretical maximum from 5 g dm<SUP>−3</SUP> glucose and xylose, respectively) by the bacterium at 70 °C and pH 8.0. Here, bioethanol production process was developed using pre-treated rice straw hydrolysate (PRSH) as low-cost agro-waste and 83.47% of the total sugar conversion was obtained. This study shows that <I>Thermoanaerobacter</I> sp. DBT-IOC-X2 could utilize diluted PRSH efficiently to improve the overall cost-effectiveness of biomass processing to bioethanol.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel C<SUB>5</SUB>-fermenting thermophilic anaerobic bacteria isolate, <I>Thermoanaerobacter</I> sp. DBT-IOC-X2, from Chumathang hot spring. </LI> <LI> Applicability of hemicellulose and inhibitor rich waste stream for cost effective ethanol production. </LI> <LI> Higher ethanol yield of 83.57% and 91.12% of the theoretical maximum from glucose and xylose, respectively. </LI> <LI> Co-sugar fermentation ability. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>