Enhanced Biobutanol Production in Folic Acid-Induced Medium by Using Clostridium acetobutylicum NRRL B-527

The conventional acetone-butanol-ethanol fermentation process suffers from several key hurdles viz. low solvent titer, insufficient yield and productivity, and solvent intolerance which largely affect butanol commercialization. To counteract these issues, the effect of stimulator, namely, folic acid was investigated in the present study to improve butanol titer. Folic acid is involved in biosynthesis of a diverse range of cellular components, which subsequently alter the amino acid balance. Therefore, different concentrations of folic acid were screened, and 10 mg/L supplementation resulted in a maximum butanol production of 10.78 ± 0.09 g/L with total solvents of 18.91 ± 0.21 g/L. Folic acid addition at different time intervals was also optimized to get additional improvements in final butanol concentration. Overall, folic acid supplementation resulted in two-fold increase in butanol concentration and thus could be considered as a promising strategy to enhance solvent titers.