Spatio-temporal niche partitioning of closely related picocyanobacteria clades and phycocyanin pigment types in Lake Constance (Germany)

Abstract

We found that the clade-specific abundance dynamics of Synechococcus type picocyanobacteria in the pelagic and littoral zone macro-habitats of Lake Constance (Germany) challenge the hypothesis of a regular annual succession of picocyanobacteria genotypes in temperate zone lakes. Methods used in this study were quantitative Taq nuclease assays (TNA), denaturing gradient gel electrophoresis (DGGE), a 19-month time series analysis (with two isothermal and two stratified periods) and genotyping of a new littoral phycocyanin (PC)-rich Synechococcus strain collection. The recorded differences between the two macro-habitats and between seasons or years, and the observed effect of water column mixis in winter on the inversion of clade-specific dominance ratios in Lake Constance might explain the known inter-annual differences in abundance and dynamics of the autotrophic picoplankton (APP) in lakes. The APP in Lake Constance shows a high genetic diversity with a low overall abundance, similar to the APP in the Baltic Sea, but different from Lake Biwa in Japan or lakes in the UK. Our results indicate that APP bloom events in both macro-habitats of Lake Constance are driven by phycoerythrin-rich Synechococcus genotypes of the Subalpine Cluster I. DGGE revealed the presence of a diverse periphyton (biofilm) community of the PC-rich Synechococcus pigment type in the littoral zone in early spring, when no such community was detectable in the pelagic habitat. A more sensitive and quantitative approach with TNA, however, revealed an intermittent presence of one PC-rich genotype in the plankton. We discuss the seasonal development of the pelagic and littoral PC-rich community, and while we cannot rule out a strain isolation bias, we found that isolated PC-rich strains from the pelagic habitat have different genotypes when compared to new littoral strains. We also observed littoral substrates colonized by specific PC-rich Synechococcus genotypes.

Optimal Defense Strategies in an Idealized Microbial Food Web under Trade-Off between Competition and Defense

“…Whereas temporal and spatial heterogeneity in environmental conditions can increase biodiversity [76], [77], the KtW-model predicts coexistence also at steady state. Hence it adds to the understanding of the paradox of plankton [18], including prokaryotes.…”

Pyrosequencing of plastid 23S rRNA genes reveals diverse and dynamic cyanobacterial and algal populations in two eutrophic lakes

“…). This reflects similar studies that demonstrate that algal or particle‐associated communities differ from water column communities (Weiss et al ., ; Steven et al ., ; Becker et al ., ). This indicates that plastid 23S was able to recapitulate previously described niche partitioning of algal communities and can be employed to differentiate algal communities that differ between habitats in the same environment or along environmental gradients.…”

Seasonal and Spatial Diversity of Picocyanobacteria Community in the Great Mazurian Lakes Derived from DGGE Analyses of 16S rDNA and cpcBA-IGS Markers

“…Initially, such studies were limited to analyses of cultured strains [15,16,18,31], but the advent of denaturing gradient gel electrophoresis (DGGE) made it possible to characterize DNA in situ, without the need to isolate and cultivate the organisms [3,5,9,33]. Despite this technical advance, there remains a dearth of available information about seasonal changes, geographic distribution, and community structure of picocyanobacteria in various types of water bodies [4]. Some studies suggest clear seasonal changes in picocyanobacteria, resembling those observed in larger phytoplankton [17].…”