Utilization of banana crop residue as an agricultural bioresource for the production of acetone-butanol-ethanol by Clostridium beijerinckii YVU1

This study aimed to produce acetone-butanol-ethanol (ABE) using lignocellulosic crop residues as renewable bioresources. Butanol production from banana crop residue (BCR) was studied using a newly isolated solventogenic Clostridium beijerinckii YVU1. BCR is one of the abundant lignocellulosic substrates available in tropical countries containing 4.3 +/- 3.5% cellulose, 28.5 +/- 3.0% hemicellulose and 20.3 +/- 2.6% lignin. The sequential dilute alkali and acid pretreatments solubilized 69% of lignin and 73% of hemicellulose. Ten percent (w/v) of pretreated substrate was subjected to enzymatic saccharification with cellulase, and it was found to release 0.481 +/- 0.035 g glucose per g pretreated biomass. In the batch fermentation process, 20.5 g l(-1) ABE (14.0 g l(-1) of butanol, 5.4 g l(-1) of acetone and 1.1 g l(-1) of ethanol) was obtained. The executed fermentation process yielded 0.39 g ABE per g hydrolysate with 0.14 g l(-1) h(-1) of volumetric productivity. On the basis of the results, we believe that sequential alkali and acid pretreatment on the enzymatic hydrolysis for butanol production is indeed a technology with the potential to be applied and newly isolated. C. beijerinckii YVU1 is also a potential candidate organism for butanol production agricultural residues.