Growth rate of Sphaerotilus in a thermally polluted environment.

In situ growth of Sphaerotilus on microscope slides immersed in a thermally polluted stream was studied. Ultraviolet radiation was used to differentiate between passive attachment of organisms from the water and growth of the organisms on the slides. Colonization of the slides in this environment took place solely by means of swarmer cells. A generation time of 2.3 hr was obtained at a water temperature of 18-22 C.