羧酸盐表面活性剂对细菌在油水界面的影响研究

Effect of Carboxylate Surfactant on the Bacterium at Oil/Water Interface

实验筛选到一株地衣芽孢杆菌,命名为DY1。对该菌株在油水界面处的运动行为、羧酸盐表面活性剂对其生理生化活动的影响进行了显微观察。细菌DY1在接触原油介质初期,由于细胞较强的亲水性,在油水界面处出现宽度约20μm的"真空带",加入羧酸盐表面活性剂后,"真空带"逐渐消失,细菌细胞开始向油水界面聚集并出现"在位繁殖"现象。实验分析表明,加入0.05%羧酸盐表活剂后,细菌DY1的代谢作用增强,产生了部分活性物质:与仅加入表活剂或单独细菌营养液相比,表面张力分别降低了28.2%、19.1%,说明羧酸盐表活剂对细菌能够起到较好的协同作用,可以促进细菌对原油的利用。物理模拟驱油实验表明,在羧酸盐表活剂的协同作用下,微生物驱油采收率比水驱提高3.7个百分点,达到5.2%(OOIP)。

A bacterial strain belonging to Bacillus licheniformis named DY1 was screened out from the producing liquid in Daqing oilfield, and the effect of carboxylate surfactant on the cells＇ physiology and metabolism was observed by microscope. On account of the cells＇ strong hydrophilicity, a vacuum space with the width 20 μm micron appeared at oil/water interface during the early stage which would fade away after adding carboxylate surfactant and the cells became gathering around the oil/water interface because of their directed migration. At the same time, the phenomenon of reproduction in situ appeared. The result of test showed that the strain DY1 could produce active agent while adding 0.05%（W/V） carboxylate surfactant, and the surface tension of fermentation broth reduced 28.2% and 19.1% respectively comparing with the system without DY1 or carboxylate surfactant. The result of physical simulation flooding showed that the oil recovery could be enhanced 5.2%（OOIP） with the synergy of carboxylate surfactant.