In situ identification of bacteria in drinking water and adjoining biofilms by hybridization with 16S and 23S rRNA-directed fluorescent oligonucleotide probes

Abstract

Free-water-phase and surface-associated microorganisms from drinking water were detected and roughly identified by hybridization with fluorescence-labeled oligonucleotide probes complementary to regions of 16S and 23S rRNA characteristic for the domains Bacteria, Archaea, and Eucarya and the beta and gamma subclasses ofProteobacteria. Samples of glass-attached biofilms and plankton were taken from a Robbins device installed in a water distribution system. More than 70% of the surface-associated cells and less than 40o of the planktonic cells visualized by 4',6-diamidino-2-phenylindole staining bound detectable amounts of rRNAtargeted probes. These findings are an indication for higher average rRNA content and consequently higher physiological activity of the attached microbial cells compared with the free-living cells. All detectable cells hybridized with the bacterial probe, whereas noArchaea and no Eucarya cells could be detected. Simultaneous hybridization with probes specific for the beta and gamma subclasses of Proteobacteria revealed that microcolonies already consisted of mixed populations in early stages with fewer than 50 cells. These observations provide further evidence that the coexistence and interaction of bacteria in drinking water biofilms may be an integral part of their growth and survival strategies.

Bacterial activity and community composition in stream water and biofilm from an urban river determined by fluorescent in situ hybridization and DGGE analysis

“…2). These ratios were within the range of values described for bio¢lms [5,9,29], river snow [26] and free-living bacteria [30,31]. We assume these represent a direct relationship between ribosome content and nutrient availability^a survival advantage that surfaces o¡er to prokaryotic cells.…”

“…During the di¡erent months sampled, bacteria on polycarbonate slides were dominated by the L subclass of Proteobacteria. This group of bacteria has been described as the most morphologically diverse group within bio¢lms [5], and a dominant group in fresh water systems such as oligotrophic lakes, drinking water bio¢lms [29,36,37], river snow [26] and eutrophic rivers [9,30]. It seems to be a common feature of most aquatic environments.…”

Microbial diversity and dynamics of a groundwater and a still bottled natural mineral water

“…Staining with DAPI (1 μg ml −1 ) and counting were performed as reported by Llobet-Brossa and colleagues (1998). The FISH procedure was based on the standard protocols described previously (Manz et al, 1993;Glockner et al, 1999). Oligonucleotide probes were 5'-monolabelled with the indocarbocyanine dye Cy3 (Thermo Fisher Scientific, Waltham, MA, USA).…”

Manure and Microbes: Public and Animal Health Problem?

“…Sensitive 16S rRNA or DNA probes, which now exist for most of the bacteria mentioned in this paper, have resulted in an improved ability to detect low levels of most of these organisms (13,33). However, these methods require careful sample handling and the use of sophisticated laboratories to ensure complete DNA extraction without contamination.…”