FIG. 3.

In situ detection of sulfate-reducing bacteria with Cy3-labeled probes SRB385 targeting members of the family Desulfovibrionaceae (a), SRB385Db targeting members of the family Desulfobacteriaceae (b), a combination of probes DSC213 and DSC441 targeting a cluster of six clones of a 16S rRNA gene clone library from the chemocline of Lake Cadagno and D. thiozymogenes (c), and SRB441 targeting a second cluster with two clones of the same 16S rRNA gene clone library (d). Cells in the background mainly represent small-celled phototrophic sulfur bacteria exhibiting strong autofluorescent signals. Arrows show hybridizing cells. Bar represents 10 μm.