Enhanced production of butanol and isopropanol from sugarcane molasses using Clostridium beijerinckii optinoii

Sugarcane molasses was studied as a substrate for butanol and isopropanol fermentation by Clostridium beijerinckii optinoii in 10 L batch fermentations. Using 3% glucose as a carbon source, the solvent concentrations (butanol and isopropanol) and solvent yields were 10.03 g/L and 0.43 g/g, respectively, with a sugar utilization of 81.7%. However, on 2.5% glucose medium supplemented with an additional 0.5% sugar supplied as sugarcane molasses, sugar consumption was 100% and the solvent concentrations (13.37 g/L) and solvent yields (0.45 g/g) were both higher. Sugarcane molasses (3%) with or without invertase and without P2 vitamin/mineral solution produced a solvent concentration of 12.15 ~ 12.81 g/L and solvent yield of. 0.39 ~ 0.41 g/g with sugar consumption of 94.88 ~ 100%. This work demonstrated the value of sugarcane molasses as a supplementary nutrient for glucose fermentation for butanol and isopropanol production using C. beijerinckii optinoii as well as its value as a low cost carbon and media source.