Waste valorization through acetone-butanol-ethanol (ABE) fermentation

Background: Biobutanol, produced through acetone-butanol-ethanol (ABE) fermentation, has been proposed for use as a transportation fuel and for the development of butanol-based materials. However, the economic viability of ABE fermentation is heavily dependent on the cost of raw materials. Methods: This study assesses various carbon and nitrogen sources for ABE fermentation. Carbon sources examined include local molasses (M1), Thai molasses (M2), Taiwan sugar agricultural molasses (M3), and Taiwan sugar edible molasses (M4). Nitrogen sources considered are corn steep liquor (CSL), acid-hydrolyzed black soldier fly larval meal (IA), and enzyme-hydrolyzed black soldier fly larval meal (IE). Significant findings: Our findings reveal that M2CSL, a combination of Thai molasses and corn steep liquor, serves as a cost-effective and efficient medium for ABE fermentation, resulting in a butanol concentration of 7.4 +/- 3.5 g/L. Furthermore, our research identifies variations in molasses and their impact on sucrose consumption inhibition. Notably, this study underscores the potential of insect peptone derived from enzyme-hydrolyzed black soldier fly larval meal (IE) as an alternative nitrogen source, while cautioning against the use of insect peptone obtained from acid-hydrolyzed black soldier fly larval meal (IA) due to its inhibitory properties.