The swarming phenomenon is characterized by a growth film which spreadsout from the colonies. In some cases, during this phenomenon the bacteria change their normal morphology to long hiperflagelated bacilli. This paper describes for the first time the uftrastructural characteristics of the swarming behavior of C. oceanicum and C. beijerinckii analyzed under transmission and scanning electron microscopy. The first species showed a complex film of growth with long hiperflagelated bacilli. C. beijerinckii showed a medusa-like colonies with short and hiperflagellated bacilli.

Swarmer phenomenon; ultrastructural; electronic microscopy