离子束诱变与连续驯化选育耐毒性产丁醇菌株

Screening of inhibitor-tolerant and butanol producing strain by ion beam implantation and continuous culturing domestication

利用离子束注入的方法对丁醇发酵菌株拜氏梭菌(Clostridium beijerinckii)NCIMB 8052进行诱变,筛选得到了突变株拜氏梭菌(Clostridium beijerinckii)CN18,相对于出发菌株,该突变株的丁醇产量从9.9 g/L增加至12.8 g/L,提高了29.3%;总溶剂产量从13.4 g/L增加至18.2 g/L,提高了35.8%。该突变菌株连续传代20次,溶剂产量稳定,菌株无明显退化。使用含木质素降解产物的培养基对该菌株进行连续培养驯化,最终获得一株耐木质素降解产物的高产突变株,命名为拜氏梭菌(Clostridium beijerinckii)CN88,其耐受木质素降解产物的质量浓度提高至1.0 g/L。在0.6 g/L、0.8 g/L、1.0 g/L的抑制物质量浓度下发酵,可分别产总溶剂15.2 g/L、14.4 g/L、12.7 g/L。

The mutation method of ion beam implantation was employed to Clostridium beijerinckii NCIMB 8052 in this study. As a result, a mutant strain C. be（ierinckii CN18 was screened. Comparing to the original strain, the buranol production increased from 9.9 g/L to 12.8 g/L, which improved 29.3%. Meanwhile, the total solvent production was 18.2 g/L, which was 35.8% higher than the original data of 13.4 g/L. Additionally, C. beijerinckii CN18 could maintain stable solvent production during 20 times serial passages, which showed excellent genetic stability. In the following, a mutant strain C. beijerinckii CN88 with high resistance of lignin-degraded products was obtained after continuous culturing domestication, which could grow well even under 1.0 g/L inhibitor. Under the inhibitor concentrations of 0.6 g/L, 0.8 g/L and 1.0 g/L, it could produce 15.2 g/L, 14.4 g/L and 12.7 g/L total solvents, respectively.