2012 Small World In Motion Competition

Tetrahymena sp. (ciliate) feeding on a biofilm composed of the bacterium Serratia plymuthica, which is expressing a red fluorescent protein

Andrew Dopheide

University of Auckland
School of Biological Sciences
Auckland, New Zealand

This video shows Tetrahymena sp. (common freshwater protozoa) cells feeding on a biofilm composed of freshwater bacterium Serratia plymuthica. The bacterial cells and biofilm structures are visible due to expression by the bacteria of a red fluorescent protein. Tetrahymena sp. cells are visible as rapidly-moving clusters of intracellular feeding vacuoles packed with red-fluorescing bacterial cells. The focal plane of the video moves down with each successive frame, revealing the effect of Tetrahymena sp. feeding activity on bacterial biofilm morphology as ciliate-sized channels and holes throughout the biofilm.