Tools for discrimination and analysis of lake bacterioplankton subgroups measured by flow cytometry in a high-resolution depth profile

Stratification of the microbial community inhabiting an anchialine sinkhole

“…Previously, multiple sub-populations of bacteria have been identified in lake communities using FCM (Button et al 1996, Andreatta et al 2004, and smallscale shifts in the relative abundance of bacterial subpopulations have been shown to occur within depth profiles (Andreatta et al 2004). However, to our knowledge this is the first study to discriminate different functional groups of bacteria according to basic FCM parameters.…”

Microscale and small-scale temporal dynamics of a coastal planktonic microbial community

“…In M2, where turbulence levels were high, all populations exhibited significantly similar cumulative sum plots. Turbulent forcing is predicted to strongly influence small-scale patterns and processes in the ocean (Rothschild & Osborn 1988, Squires & Yamazaki 1995, Jimenez 1997, Kiørboe 1997, and close coupling between turbulent mixing and smallscale spatial variations in the abundance of bacteria has been observed (Andreatta et al 2004). While it is difficult to predict the extent to which physical processes directly influenced the patterns observed here, the temporal variability and patterns observed here indicate that processes operating on time scales of seconds to minutes can exert significant control over the abundance and activity of planktonic microbial communities in the ocean.…”

“…Microscale patches of dissolved organic and inorganic substrates may provide important, albeit ephemeral, growth habitats for heterotrophic (Mitchell et al 1985, Blackburn et al 1997, 1998, Blackburn & Fenchel 1999 and autotrophic microorganisms (Lehman & Scavia 1982, Seuront et al 2002, while suspended and sinking particulate matter also provides unique microhabitats of increased nutrients for attached (Bidle & Azam 1999, Grossart et al 2003) and free-living microorganisms (Kiørboe & Jackson 2001). In addition, physical processes are likely to affect planktonic life at a variety of scales (Marrasé et al 1997), and turbulence has repeatedly been shown to control the extent of variability observed in the small-scale distributions of nutrients (Seuront et al 2002), bacteria (Seymour et al 2000, Andreatta et al 2004) and phytoplankton (Seuront et al 1999 Given that the mechanisms responsible for developing and maintaining heterogeneity amongst aquatic microbial communities vary according to scale, the extent and nature of biological variability will also differ with scale. Small-and microscale variability in microbial parameters can often be as great as, or greater than, the variability observed at the ocean's largest scales.…”

Suitability of Flow Cytometry for Estimating Bacterial Biovolume in Natural Plankton Samples: Comparison with Microscopy Data

“…FC has become a key tool in aquatic microbial ecology because it constitutes a rapid cell counting method and also makes it possible to process a high number of samples in a short time (33). Besides estimates of bacterial abundance, FC also provides information on single-cell parameters (e.g., light scatter values and specific channels of fluorescence) that can be useful for further discriminating distinct fractions of bacteria within mixed assemblages and thus for analyzing the heterogeneity of bacterial communities (3,11,38). The increase in commercially available fluorochromes, the use of molecular techniques, the application of cell sorting, and technological progress have improved the methods for single-cell analysis and the discrimination of physiological and taxonomical diversity within bacterial assemblages (see references 5, 12, and 19).…”