We investigated net growth rates of distinct bacterioplankton groups and heterotrophic nanoflagellate (HNF) communities in relation to phosphorus availability by analysing eight in situ manipulation experiments, conducted between 1997 and 2003, in the canyon-shaped Rímov reservoir (Czech Republic). Water samples were size-fractionated and incubated in dialysis bags at the sampling site or transplanted into an area of the reservoir, which differed in phosphorus limitation (range of soluble reactive phosphorus concentrations--SRP, 0.7-96 microg l-1). Using five different rRNA-targeted oligonucleotide probes, net growth rates of the probe-defined bacterial groups and HNF assemblages were estimated and related to SRP using Monod kinetics, yielding growth rate constants specific for each bacterial group. We found highly significant differences among their maximum growth rates while insignificant differences were detected in the saturation constants. However, the latter constants represent only tentative estimates mainly due to insufficient sensitivity of the method used at low in situ SRP concentrations. Interestingly, in these same experiments HNF assemblages grew significantly faster than any bacterial group studied except for a small, but abundant cluster of Betaproteobacteria (targeted by the R-BT065 probe). Potential ecological implications of different growth capabilities for possible life strategies of different bacterial phylogenetic lineages are discussed.

Biological Centre of the Academy of Sciences of the Czech Republic Hydrobiological Institute Na Sádkách 7 CZ 37005 Ceské Budejovice Czech Republic

References provided by Crossref.org

Seasonal dynamics of aerobic anoxygenic phototrophs in freshwater lake Vlkov

Determining lineage-specific bacterial growth curves with a novel approach based on amplicon reads normalization using internal standard (ARNIS)

Synchrony of Eukaryotic and Prokaryotic Planktonic Communities in Three Seasonally Sampled Austrian Lakes

Cryptophyta as major bacterivores in freshwater summer plankton

Aerobic Anoxygenic Photosynthesis Is Commonly Present within the Genus Limnohabitans

The Limnohabitans Genus Harbors Generalistic and Opportunistic Subtypes: Evidence from Spatiotemporal Succession in a Canyon-Shaped Reservoir

Prey-Specific Growth Responses of Freshwater Flagellate Communities Induced by Morphologically Distinct Bacteria from the Genus Limnohabitans

Differential freshwater flagellate community response to bacterial food quality with a focus on Limnohabitans bacteria

Patterns of Limnohabitans microdiversity across a large set of freshwater habitats as revealed by Reverse Line Blot Hybridization

The diversity of the Limnohabitans genus, an important group of freshwater bacterioplankton, by characterization of 35 isolated strains

Every coin has a back side: invasion by Limnohabitans planktonicus promotes the maintenance of species diversity in bacterial communities

Alga-derived substrates select for distinct Betaproteobacterial lineages and contribute to niche separation in Limnohabitans strains

Limnohabitans australis sp. nov., isolated from a freshwater pond, and emended description of the genus Limnohabitans

Limnohabitans planktonicus sp. nov. and Limnohabitans parvus sp. nov., planktonic betaproteobacteria isolated from a freshwater reservoir, and emended description of the genus Limnohabitans

Assessing niche separation among coexisting Limnohabitans strains through interactions with a competitor, viruses, and a bacterivore

Broad habitat range of the phylogenetically narrow R-BT065 cluster, representing a core group of the Betaproteobacterial genus Limnohabitans