Evolutionary Engineering of E. coli MG1655 for Tolerance Against Isoprenol

Isoprenol is the basis for industrial flavor and vitamin synthesis and also a promising biofuel. Biotechnological production of isoprenol with E. coli is currently limited by the high toxicity of the final product. Adaptive laboratory evolution (ALE) is a promising method to address complex biological problems such as toxicity.Results: Here we applied this method successfully to evolve E. coli towards high tolerance against isoprenol, increasing growth at the half-maximal inhibitory concentration by 47 %. Whole-genome re-sequencing of strains isolated from three replicate evolutions at seven different time-points identified four major target genes for isoprenol tolerance: fabF, marC, yghB and rob.

异戊烯醇（Isoprenol）是工业香料与维生素合成的基础原料，同时也是一种极具应用前景的生物燃料。目前利用大肠杆菌（E. coli）通过生物法生产异戊烯醇的工艺，受限于终产物的高毒性。自适应实验室进化（Adaptive laboratory evolution, ALE）是解决毒性等复杂生物学问题的极具潜力的技术方法。结果：本研究成功运用该方法对大肠杆菌进行进化改造，使其获得对异戊烯醇的高耐受性，在半最大抑制浓度下的菌体生长量提升了47%。对三次平行重复进化实验中七个不同时间点分离得到的菌株进行全基因组重测序，最终鉴定出四个与异戊烯醇耐受性相关的核心靶基因：fabF、marC、yghB和rob。