ABSTRACT
Ribosome Content and Percentage of CTC-Reducing Cells during Biofilm Formation
In contrast to the number of CTC-reducing cells, the amount of cells with positive hybridization signals declined very slowly during the first 21 days of biofilm formation on glass surfaces from 90% (±3% ) to 82% (±2% ) (Figure 1). After 35 days of exposure, the percentage of detectable cells after hy bridization was reduced to 52% (±5% ) of total cell counts and remained sta ble at this level. This decrease of fluorescence signal intensity was observed in all experiments performed on biofilms on glass and polyethylene slides. Comparative studies between these two independent methods showed that flu orescence signals and the supposed corresponding cellular ribosome content declined more slowly than bacterial in situ or substrate-dependent respiratory activity. These findings are in agreement with results from Fukui et al. (1996), who suggest a certain amount of a durable fraction of rRNAs in starved bac terial cells.
