Isopropanol-butanol production from sugarcane and sugarcane-sweet sorghum juices by Clostridium beijerinckii DSM 6423

Butanol and isopropanol are important commodity chemicals with a variety of applications. n-Butanol is considered an advanced biofuel, and isopropanol has good properties as a fuel additive. In this work, isopropanol and butanol (IB) production from sugarcane and a mixture of sugarcane-sweet sorghum industrial juices by Clostridium beijerinckii DSM 6423 were studied. The addition of a buffer and mineral P2 stock solutions, a commercial vitamin complex instead of pure vitamins, and yeast extract was necessary to obtain high isopropanol and butanol concentrations. Fermentation was performed with the simultaneous extraction of solvents by gas stripping. Total sugar conversion, isopropanol and butanol concentrations of 10.9 and 7.8 g L-1, and an IB yield and productivity of 0.27 g g(-1) and 0.11 g L-1 h(-1) were achieved, respectively.