FIG. 1.

Bacterial phyla present and their proportional abundances (percentages of total) among isolates cultured on R2A medium and sequences in the clone library. Identification of strains and clones is based on 16S rRNA sequence analysis. The upper part represents subclasses of Proteobacteria, whereas the lower part represents other phyla detected. Some isolates could not be identified, which is the reason why some bars sum to less than 100%. The young biofilm category includes ages from 1 to 256 days, and the old biofilm category includes ages from 571 to 1,093 days. Bulk samples are from the inlet and outlet.