Acetone-Butanol-Ethanol (ABE) fermentation with Clostridial Co-cultures for Enhanced Biobutanol Production

Abstract

This study investigates acetone-butanol-ethanol (ABE) fermentation, a process using solventogenic Clostridium species to produce acetone, butanol, and ethanol. Recent biotechnological advancements, such as omics, systems biology, and metabolic engineering, have reignited interest in butanol production, responding to the increasing gasoline costs and the demand for sustainable energy systems. This study unravels the distinct physiological attributes of C. acetobutylicum (Cac) and C. pasteurianum (Cpa), significantly impacting sustainable bioenergy technologies. Employing response surface methodology (RSM), we embarked on a comprehensive statistical optimization journey in the co-culture system, Cac MTCC 11274 and Cpa MTCC 116, enhancing biobutanol production from mixed substrates. A spectrum of process parameters was scrutinized, encompassing the ratio of Cac and Cpa inoculum, sodium concentration, and the ratio of xylose to glucose. Statistical analysis revealed salt concentrations profound influence on biomass, total alcohol, and butanol production. The culmination of these endeavors yielded highly promising outcomes: a butanol concentration of 12.1 {+/-} 0.45 g L-1 (model prediction: 11.87 g L-1), biomass of 4.15 {+/-} 0.03 (model prediction: 4.06 OD600), and ABE concentration of 23.1 {+/-} 0.55 g L-1 (model prediction: 22.45 g L-1). These results represent a significant leap forward in bioenergy technologies, offering both practical insights and sustainable solutions for enhanced biofuel production.