Illinois Institute of Technology, 3101 South Dearborn Street, Chicago, Illinois 60616, USA.
Phys Rev Lett. 2009 Oct 2;103(14):148101. doi: 10.1103/PhysRevLett.103.148101. Epub 2009 Sep 29.
Measurements of the shear viscosity in suspensions of swimming Bacillus subtilis in free-standing liquid films have revealed that the viscosity can decrease by up to a factor of 7 compared to the viscosity of the same liquid without bacteria or with nonmotile bacteria. The reduction in viscosity is observed in two complementary experiments: one studying the decay of a large vortex induced by a moving probe and another measuring the viscous torque on a rotating magnetic particle immersed in the film. The viscosity depends on the concentration and swimming speed of the bacteria.
在自由站立的液体膜中游泳枯草芽孢杆菌悬浮液的剪切粘度测量表明，与不含细菌或非运动细菌的相同液体相比，粘度可降低多达 7 倍。在两个互补的实验中观察到粘度的降低：一个研究由移动探针引起的大涡的衰减，另一个测量浸入膜中的旋转磁性粒子上的粘性扭矩。粘度取决于细菌的浓度和游动速度。
