Solvents production from cassava by co-culture of Clostridium acetobutylicum and Saccharomyces cerevisiae

Abstract

Co-culture of Clostridium acetobutylicum and Saccharomyces cerevisiae was used to enhance solvents (acetone-butanol-ethanol, ABE) production from cassava without amylolytic enzymes addition. Under the simultaneous inoculation condition of C. acetobutylicum and S. cerevisiae with the inoculation level of 5% (v/v) for both strains, 21.74g/L solvents was produced from 75g/L cassava with the yield of 0.36g solvents/g glucose. The solvents titer and yield obtained in the co-culture process increased by 14.3% and 9.1%, respectively, compared to those achieved in ABE fermentation. For further improvements in total solvents titer and yield from cassava, ABE fermentation and co-culture process from higher cassava concentration media were conducted. 42.56g/L total solvents was achieved from 150g/L cassava by co-culture with the yield of 0.46g solvents/g glucose. The solvents titer and yield obtained in the co-culture process increased by 141.0% and 43.8%, respectively, compared to those obtained from ABE fermentation. The results showed great potential for the use of co-culture of C. acetobutylicum and S. cerevisiae for solvents production from starchy substrate.