A proposed helical mechanism for gliding motility in three gliding bacteria (order Cytophagales)

Observations of a typical Cytophaga sp. and two unclassified gliding bacteria, using phase-contrast microscopy and videotaping techniques, revealed that the bacteria rotated sinistrally at strain-specific rates as they glided. Microscopic spheres attached to the bacteria moved in helical paths around them. The machinery of gliding is conjectured, therefore, to be orientated helically on the cell surface, and probably acts on a substratum via an adhesive polymer network. Cells and surfaces often appear to be connected at some distance by an invisible elastic material, which might be equated to fibrous structures observed extending from cells. Variations in motility behaviour between strains could be explained by differences in the orientation of moving cell surface elements, in the amount and type of adhesive polymer surrounding cells, and in the distance at which attached bacteria lie from their substrata.