Selected FISH and corresponding bright-field MAR micrographs.

<p>FISH probes and MAR substrate are indicated for each image set. Target cells in FISH micrograph overlays appear yellow [target probe (Cy3 = red) + EUBmix (FLUOS) = green] and non-target green (EUBmix only). Circles indicate location of FISH-positive cells. Black silver granules indicate positive MAR signal: <b>a.-g.</b> show positive MAR signal for cells hybridizing with the specific FISH probe; <b>h.</b> shows a negative MAR signal. Images represent incubations performed under either aerobic (<b>a. and c.-h.</b>) or anaeorbic incubation conditions (<b>b.</b>) with biomass from the Randers (<b>a., b., d. and f.-h.</b>) or the Ejby Mølle (<b>c. and e.</b>) WWTPs. Scale bars represent 10 μm.