Butanol production from hemicellulosic hydrolysate of corn fiber by a Clostridium beijerinckii mutant with high inhibitor-tolerance

A Clostridium beijerinckii mutant RT66 with considerable inhibitor-tolerance obtained by continuous culture was used for butanol production from non-detoxified hemicellulosic hydrolysate of corn fiber treated with dilute sulfuric acid (SAHHC). In fed-batch fermentation, 1.8. L of diluted SAHHC containing 10. g/L of reducing sugar was provided during the acidogenic phase and 0.2. L of concentrated SAHHC containing 300. g/L of reducing sugar was provided during the solventogenic phase. The mutant produced a total amount of solvents of 12.9. g/L, which consisted of 3.1. g/L of acetone, 9.3. g/L of butanol and 0.5. g/L of ethanol. A solvent yield of 0.35. g/g sugar and a productivity of 0.18. g/L. h in 72. h were achieved. The remarkable inhibitor-tolerance of C. beijerinckii RT66 demonstrates that this may be an excellent strain for butanol production from ligocellulosic materials.