ATPase and cytochrome oxidase activities at the polar organelle in swarm cells of Sphaerotilus natans: an ultrastructural study.

The polar organelle of bacteria presumably is part of the flagellar apparatus. In order to characterize this structure, cytochemical studies on Sphaerotilus natans have been performed. Marked ATPase activity is associated with the inner boundary layer and central layer of this organelle. The spaces between the boundary layers and the central layer of the polar organelle which are traversed by fine fibrilles are positive for reactions with diaminobenzidine. This indicates cytochrome oxidase activity. S. natans possesses a ribbon-like, helically shaped polar organelle which is divided concomitantly with cell fission, possibly explaining inheritance of this structure and of the flagellar apparatus.