为了提高丙酮丁醇梭菌对分子氧的耐受能力,降低厌氧发酵环境,构建了超氧化物阻遏蛋白(PERR)基因敲除的工程菌株。应用Ⅱ组内含子敲除系统,PCR克隆perR-Targetron基因与载体连接构建敲除质粒pSYperR,电转化丙酮丁醇梭菌C.acetobutylicum ATCC 824,PCR筛选验证获得突变菌株C.acetobutylicum ATCC 824-δperR,采用摇瓶发酵对其突变菌株进行发酵性能研究。结果表明:静止状态发酵丁醇C.acetobutylicum ATCC824-δperR比C.acetobutylicum ATCC 824丁醇产量提高7.89%,摇床转速为200 r/min时,C.acetobutylicum ATCC824-δperR的丁醇产量是C.acetobutylicum ATCC 824的3.34倍。研究表明,通过Ⅱ组内含子敲除系统,构建的C.acetobutylicum ATCC824-δperR在发酵过程中降低了氧分子的伤害,不需要严格的厌氧条件,从而降低发酵成本。

In order to reduce the anaerobic fermentation environment and enhance the tolerance of molecular oxygen,a Clostridium acetobutylicum mutant with peroxide regulon repressors( perR) gene in-frame deletion was constructed through Group Ⅱ Intron knock-out recombination. The effect of perR knock-out on fermentation characteristics of the mutant was investigated by shake-flask fermentation experiments. The fermentation results showed that C. acetobutylicum ATCC824-δperR could enhance the yield of butanol with 7. 89% by the stationary state fermentation compared with the C. acetobutylicum ATCC 824. The yield of butanol of C. acetobutylicum ATCC 824-δperR was 3. 34 times that of C. acetobutylicum ATCC 824 when the rotate speed was 200 r / min. Results showed that C. acetobutylicum ATCC 824-δperR constructed by group II introns knock out system could reduce molecular oxygen damage in the process of fermentation,thus reduce fermentation costs.