复合诱变选育丙酮丁醇梭菌发酵玉米秸秆水解液

Screening of Clostridium acetobutylicum for Fermentation of Corn Fiber Hydrolysate by Complex Mutagenesis

[目的]提高丙酮丁醇梭菌CICC8012产丁醇能力。[方法]采用紫外线和甲基磺酸乙酯(EMS)复合诱变选育丙酮丁醇梭菌CICC8012。[结果]紫外辐照120 s,5%EMS处理60 m in条件下,筛选得到1株遗传稳定性良好的高产突变株M-31,其在葡萄糖培养基中总溶剂产量10.39 g/L,丁醇产量6.55 g/L,较出发菌株分别提高了16.48%和20.62%。对M-31玉米秸秆水解液发酵培养基进行优化,得到最优工艺组合:初始水解糖浓度为80 g/L,(NH4)2SO43 g/L,KH2PO40.6 g/L,MgSO4.7H2O 0.4 g/L,FeSO4.7H2O 15 mg/L,并选择亚硫酸盐法对秸秆水解液进行脱毒,丁醇和总溶剂产量分别达到5.19和8.27 g/L,较优化前分别提高了55.39%和55.74%。[结论]得到的高产突变株较出发菌株丁醇产量更高、更适合于生物质发酵。

[Objective] The ability in butanol produced from Clostridium acetobutylicum——CICC8012 would be improved through the experiment.[Method] The Clostridium acetobutylicum——CICC8012 complexly mutated by UV and EMS was formed.[Result] The results showed that M-31 with high yield and hereditary stability was obtained under the condition of UV of 120s and EMS of 60 minutes.The yield of total solvent and butanol produced from M-31 were 10.39 g/L and 6.55 g/L,which were 16.48 % and 20.62 % higher than the original strain in glucose media.The optimal composition of corn fiber hydrolysate fermentation media was determined as follows： the initial concentration of hydrolysate sugar in corn fiber was 80 g/L;（NH4）2SO4,3 g/L;KH2PO4,0.6 g/L;MgSO4·7H2O,0.4 g/L and FeSO4·7H2O,15 mg/L,and also the corn fiber hydrolysate was detoxified with the method of NaSO3.so that the yield of total solvent and butanol was 8.27 g/L and 5.19 g/L,which were 55.74 % and 55.39 % higher than these before optimization,respectively.[Conclusion] The mutant strain with higher ability in the production of butanol compared with its initial strain was much more suitable for the fermentation of biomass.