复合诱变选育丙酮丁醇梭菌发酵玉米秸秆水解液

摘要

[目的]提高丙酮丁醇梭茵C1CC8012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茵ClCC8012.[结果]紫外辐照120s.5％EMS处理60 min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6.55g/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 resultsshowed 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.