N-butanol, a valued solvent and potential fuel extender, could possibly be produced by fermentation using either native producers, i.e. solventogenic Clostridia, or engineered platform organisms such as Escherichia coli or Pseudomonas species, if the main process obstacle, a low final butanol concentration, could be overcome. A low final concentration of butanol is the result of its high toxicity to production cells. Nevertheless, bacteria have developed several mechanisms to cope with this toxicity and one of them is active butanol efflux. This review presents information about a few well characterized butanol efflux pumps from Gram-negative bacteria (P. putida and E. coli) and summarizes knowledge about putative butanol efflux systems in Gram-positive bacteria.

正丁醇，一种有价值的溶剂和潜在的燃料增量剂，可以通过使用天然生产商（即产溶剂梭菌）或工程化平台生物（如大肠杆菌或假单胞菌属）进行发酵生产，如果主要工艺障碍是最终丁醇的浓度低，可以克服。丁醇终浓度低是由于它对生产细胞具有高毒性。然而，细菌已经开发出多种机制来应对这种毒性，其中一种是活性丁醇外排。这篇综述介绍了一些革兰氏阴性细菌（恶臭假单胞菌和大肠杆菌）中丁醇外排泵的特征。），并总结了有关革兰氏阳性细菌中假定的丁醇外排系统的知识。