Genetic diversity in strains of the genus Anabaena isolated from planktonic and benthic habitats of the Gulf of Finland (Baltic Sea)

Abstract

Late summer cyanobacterial blooms in the Baltic Sea contain Anabaena sp. together with Nodularia spumigena and Aphanizomenon flos-aquae. Although Anabaena is common especially in the Gulf of Finland, very little is known about its genetic diversity. Here we undertook a molecular phylogenetic study of 68 Anabaena strains isolated from the brackish Gulf of Finland. We sequenced the 16S rRNA genes from 54 planktonic and 14 benthic Anabaena strains, and rbcL and rpoC1 genes from a subset of these strains. Phylogenetic trees showed that Anabaena strains, from both planktonic and benthic habitats, were genetically diverse. Although the Anabaena strains were morphologically diverse, in our study only one genetically valid species was found to exist in the plankton. Evolutionary distances between benthic Anabaena strains were greater than between planktonic strains, suggesting that benthic habitats allow for the maintenance of greater genetic diversity than planktonic habitats. A number of novel lineages containing only sequences obtained in this study were compiled in the phylogenetical analyses. Thus, it seemed that novel lineages of the genus Anabaena may be present in the Baltic Sea. Our results demonstrate that the Baltic Sea Anabaena strains show surprisingly high genetic diversity.

Planktonic and benthic cyanobacteria of European brackish waters: a perspective on estuaries and brackish seas

“…In the Guadiana estuary (Portugal) the presence of MCs has also been reported, produced either by Microcystis or Oscillatoria species (Sobrino et al, 2004). MCs had already been reported from the north-east of Europe, in the brackish waters of Baltic Sea, where they were produced by planktonic and benthic Anabaena species (Halinen et al, 2007(Halinen et al, , 2008. Outside Europe, microcystins have been detected mainly in North America (e.g.…”

“…E-mail: vmvascon@ fc.up.pt Tan, 2007). The cyanobacteria of brackish waters (including estuaries), however, remain under-investigated, particularly in Europe, despite a number of significant contributions (Sivonen et al, 1989;Nehring, 1993;Lehtima¨ki et al, 1994Lehtima¨ki et al, , 1997Lehtima¨ki et al, , 2000Wille´n & Mattson, 1997;Sivonen & Jones, 1999;Sipia¨et al, 2001Sipia¨et al, , 2002Sipia¨et al, , 2006Sipia¨et al, , 2007Sipia¨et al, , 2008Vasconcelos & Cerqueira, 2001;Laamanen et al, 2002;Rocha et al, 2002;Geiss et al, 2003;Hobson & Fallowfield, 2003;Lehtonen et al, 2003;Stal et al, 2003;Sobrino et al, 2004;Herfindal et al, 2005;Kankaanpa¨a¨et al, 2005;Karjalainen et al, 2005Karjalainen et al, , 2007Karlsson et al, 2005;Pere´z & Carrilo, 2005;Surakka et al, 2005;Marino et al, 2006;Mazur-Marzec et al, 2007Paoli et al, 2007;Halinen et al, 2008;Ibelings & Havens, 2008;Jo´z´wiak et al, 2008;Lopes et al, 2010;Oftedal et al, 2010;). This lack of information for brackish-water cyanobacteria is especially significant in relation to the potential for production of new bioactive compounds.…”

“…Various Anabaena species, which comprise heterocystous filamentous, planktonic and benthic forms, have been reported in European brackish waters, especially in the Baltic (Wille´n & Mattsson, 1997;Halinen et al, 2008). Aphanizomenon species possess diverse morphologies.…”

Genetic diversity and molecular phylogeny of Planktothrix (Oscillatoriales, cyanobacteria) strains from China

“…However, several studies, using the bacteriological standard for the cut-off points of 97.5% and 95.0% 16S rRNA gene sequence similarity for species and genus definition respectively, have been performed to analyze the genetic diversity in closed related cyanobacterial strains (Halinen et al, 2008;Rajaniemi et al, 2005). Suda et al (2002) established the new species-P. pseudagardhii primarily based on 16S rRNA gene sequences by the phylogenetic analysis.…”

Dolichospermum uruguayense sp. nov., a planktic nostocacean cyanobacterium from the Lower Uruguay River, South America

“…length and width of all cell types, their shapes, akinete arrangement and the general morphology of filaments (for the reviews see KomáreK & KomárKová 2006;KomáreK & zapomělová 2007KomáreK & zapomělová , 2008KomáreK 2013). However, phylogenetic analyses of planktic (gas-vacuolate) and benthic (non-gas-vacuolate) representatives revealed pronounced differences between these two groups (rajaniemi et al 2005a, b;Halinen et al 2008) and resulted in reclassification of the main phylogenetic clade of planktic morphospecies into the new genus Dolichospermum (ralFs ex Born. et FlaH.)…”