12
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: not found
      • Article: not found

      Prokaryotic assemblages in the maritime Antarctic Lake Limnopolar (Byers Peninsula, South Shetland Islands)

      Read this article at

      ScienceOpenPublisher
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Related collections

          Most cited references44

          • Record: found
          • Abstract: not found
          • Article: not found

          The use of DAPI for identifying and counting aquatic microflora1

            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Evaluating rRNA as an indicator of microbial activity in environmental communities: limitations and uses.

            Microbes exist in a range of metabolic states (for example, dormant, active and growing) and analysis of ribosomal RNA (rRNA) is frequently employed to identify the 'active' fraction of microbes in environmental samples. While rRNA analyses are no longer commonly used to quantify a population's growth rate in mixed communities, due to rRNA concentration not scaling linearly with growth rate uniformly across taxa, rRNA analyses are still frequently used toward the more conservative goal of identifying populations that are currently active in a mixed community. Yet, evidence indicates that the general use of rRNA as a reliable indicator of metabolic state in microbial assemblages has serious limitations. This report highlights the complex and often contradictory relationships between rRNA, growth and activity. Potential mechanisms for confounding rRNA patterns are discussed, including differences in life histories, life strategies and non-growth activities. Ways in which rRNA data can be used for useful characterization of microbial assemblages are presented, along with questions to be addressed in future studies.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Optimizing fluorescent in situ hybridization with rRNA-targeted oligonucleotide probes for flow cytometric identification of microorganisms.

              A combination of fluorescent rRNA-targeted oligonucleotide probes ("phylogenetic stains") and flow cytometry was used for a high resolution automated analysis of mixed microbial populations. Fixed cells of bacteria and yeasts were hybridized in suspension with fluorescein- or tetramethylrhodamine-labeled oligonucleotide probes complementary to group-specific regions of the 16S ribosomal RNA (rRNA) molecules. Quantifying probe-conferred cell fluorescence by flow cytometry, we could discriminate between target and nontarget cell populations. We critically examined changes of the hybridization conditions, kinetics of the hybridization, and posthybridization treatments. Intermediate probe concentrations, addition of detergent to the hybridization buffer, and a posthybridization washing step were found to increase the signal to noise ratio. We could demonstrate a linear correlation between growth rate and probe-conferred fluorescence of Escherichia coli and Pseudomonas cepacia cells. Oligonucleotides labeled with multiple fluorochromes showed elevated levels of nonspecific binding and therefore could not be used to lower the detection limits, which still restrict studies with fluorescing rRNA-targeted oligonucleotide probes to well-growing microbial cells. Two probes of different specificities--one labeled with fluorescein, the other with tetramethylrhodamine--could be applied simultaneously for dual color analysis.
                Bookmark

                Author and article information

                Journal
                Extremophiles
                Extremophiles
                Springer Science and Business Media LLC
                1431-0651
                1433-4909
                November 2017
                September 21 2017
                November 2017
                : 21
                : 6
                : 947-961
                Article
                10.1007/s00792-017-0955-x
                8a80d611-0d2e-438e-baca-ab4f228bd38f
                © 2017

                http://www.springer.com/tdm

                History

                Comments

                Comment on this article