Market refused vegetables as a supplement for improved acetone–butanol–ethanol production by Clostridium acetobutylicum DSM 792

The present study proposes the use of market rejected and waste vegetables as a supplement for improved acetone–ethanol–butanol (ABE) solvent production. In the present study, three different perishable vegetables were evaluated as supplements for ABE fermentation. These vegetables were found to stimulate the solvent production at as low as 1% (w/v) concentration. The supplementation showed improved production of solvents using 4-fold diluted SO2–ethanol–water (SEW) spent liquor supplemented with 25 g/l glucose as a substrate. The maximum total solvent production obtained with 5% (w/v) supplementation of carrot, cabbage and tomato was 9.96 g/l, 10.49 g/l and 10.65 g/l, respectively as compared to the control value of 7.43 g/l. The applicability of vegetables was successfully evaluated as a complex medium for solvent production.

► Suggest effective use of waste vegetables for ABE production. ► Improvement in solvent production using sugar mixture as well as wood hydrolysate. ► Waste vegetables can be used as complex medium for solvent production. ► As low as 1% (w/v) supplementation enhances solvent production significantly.