Optimization of butanol production from corn straw hydrolysate by <Emphasis Type="Italic">Clostridium acetobutylicum</Emphasis> using response surface method

Butanol is a new kind of very potential biofuels. Enzymatic hydrolysis of corn stalk was utilized in this study to produce butanol by Clostridium acetobutylicum CICC 8008. Plackett-Burman (P-B) design and Central Composite Design (CCD) were adopted to screen crucial factors during fermentation as well as the optimization of experimental conditions. The result demonstrated that among the seven factors, namely, Yeast extract, (NH₄)₂SO₄, KH₂PO₄, MgSO₄, FeSO₄, CuSO₄ and CaCO₃, only CaCO₃ was selected as the most critical factor. The optimization experiment results for CaCO₃ usage, temperature and reaction time by CCD were determined to be 5.04 g/L, 35°C and 70 h, respectively. A corresponding mathematical model was established to predict the fermentation experiment and maximum butanol yield of 6.57 g/L was acquired. The result of verification experiment under the optimum conditions showed that 6.20 g/L was the maximum butanol yield. This demonstrated that statistical method was a powerful tool for the optimization of butanol production from enzymatic hydrolysis of corn stalk.