抄録
The sedimentation rates of enterobacterias Proteus mirabilis (Pm) and Escherichia coli (Ec) were measured in physiological saline solutions as functions of temperature and volume fraction. The Stokes velocity was estimated with the observed density and viscosity of the suspension and the dimensions of the enterobacterias. The observed and calculated sedimentation rates of Ec agreed well with each other, while the calculated sedimentation rate of Pm was much. larger than that observed at 20°C. With rise in the temperature, the sedimentation rate of Ec showed monotonic increase, while that of Pm dipped to a minimum at 37°C. Swarming velocity of Pm reached a maximum at 37°C, as well. This characteristic behavior of Pm may be related to the optimum temperature of 37°C for inducing activity both in saline solution and on a wet surface.
