Abstract: Pseudomonas sp. S-7 strain can produces glucolipid and lipopeptide in metabolism. The critical micelle concentration of surfactants is 36mg/L. Surfactants make the surface tension of water decrease from 72mN/m to 29.7mN/m, and make the interfacial tension between oil and water reduce from 30mN/m to 1.3mN/m. The fermented broth has stable surface activity at different temperature, pH and salinity; it emulsifies crude oil and makes the viscosity of crude oil decrease 86.95%. The present study states that the surfactants are major factors of S-7 strain in microbial enhanced oil recovery.

Key words: Pseudomonas, biosurfactant, surface tension, interfacial tension, crude oil

摘要： 假单胞菌S-7菌株在代谢过程中能够产生糖脂和脂肽表面活性物质，其临界胶束浓度（CMC）为36mg/L，可以将水的表面张力由72mN/m降到29.7mN/m，油水界面张力由30mN/m降到1.3mN/m。发酵液在不同的温度、pH和矿化度条件下，具有稳定的表面活性。发酵液可以乳化原油，使原油的粘度降低86.95%。研究表明，表面活性物质是S-7菌株在微生物采油过程中发挥作用的主要因素。

关键词: 假单胞菌, 生物表面活性剂, 表面张力, 界面张力, 原油