Aerotaxis in Desulfovibrio
Aerotactic band formation by Desulfovibrio desulfuricans (DSM 9104) was studied
in a stopped-flow diffusion chamber. This chamber allowed us to create reproducible,
steep oxygen gradients in a flat capillary, time-lapse video recordings and
spatio-temporal analysis of band formation. The cells formed two types of bands.
Bands of the first type evolved quickly after starting the experiment and were
located near the oxic–anoxic interface. Bands of the second type typically appeared
several minutes later and a few millimeters inside the initially anoxic volume of the
capillary. Band formation depended on metabolism and could be stimulated by
lactate addition, and thus appears to be energy taxis. Mathematical modeling of
oxygen diffusion and respiration within the chamber revealed that bands formed
preferentially at oxygen concentrations close to 4% air saturation. The swimming
speed of the cells was determined by digital single-cell tracking and found to be
highest close to the oxic–anoxic interfaces. Motility patterns
were influenced by surfaces, at which cells accumulated. Bioconvection sometimes
occurred if very dense bands had formed. The ecological implications of these two
phenomena are unknown.
Team members
Cooperation
Links
Publications
- Fischer J, Cypionka H (2006) Analysis of aerotactic band formation by Desulfovibrio desulfuricans in a stopped-flow diffusion chamber. FEMS Microbiol Ecol 55:186-194
- Sass AM, Eschemann A, Kühl M, Thar R, Sass H, Cypionka H (2002) Growth and chemosensory behavior of sulfate-reducing bacteria in oxygen-sulfide gradients. FEMS Microbiol Ecol 40:47-54
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Eschemann, A, Kühl M, Cypionka H (1999) Aerotaxis in Desulfovibrio. Environ Microbiol 1:489-495
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