Open AccessSpatio‐temporal niche partitioning of closely related picocyanobacteria clades and phycocyanin pigment types in L ake C onstance ( G ermany)
Author(s) -
Becker Sven,
SánchezBaracaldo Patricia,
Singh Arvind K,
Hayes Paul K
Publication year - 2012
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2012.01316.x
Subject(s) - biology , picoplankton , pelagic zone , synechococcus , ecology , littoral zone , water column , temperature gradient gel electrophoresis , cyanobacteria , phytoplankton , 16s ribosomal rna , genetics , nutrient , bacteria
Abstract We found that the clade‐specific abundance dynamics of S ynechococcus type picocyanobacteria in the pelagic and littoral zone macro‐habitats of L ake C onstance ( G ermany) challenge the hypothesis of a regular annual succession of picocyanobacteria genotypes in temperate zone lakes. Methods used in this study were quantitative T aq 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 S ynechococcus 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 L ake C onstance shows a high genetic diversity with a low overall abundance, similar to the APP in the B altic S ea, but different from L ake B iwa in J apan or lakes in the UK . Our results indicate that APP bloom events in both macro‐habitats of L ake C onstance are driven by phycoerythrin‐rich S ynechococcus genotypes of the S ubalpine C luster I . DGGE revealed the presence of a diverse periphyton (biofilm) community of the PC ‐rich S ynechococcus 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 S ynechococcus genotypes.