Diversity of hepatotoxic microcystins and bioactive anabaenopeptins in cyanobacterial blooms from Greek freshwaters

Abstract

Microcystins (MCs) and anabaenopeptins from 26 cyanobacterial bloom samples dominated mainly by the genus Microcystis and collected from seven Greek freshwaters were identified and quantified by high-performance liquid chromatography coupled to a diode array detector. All the samples analyzed contained microcystins; in 27% of the samples anabaenopeptins were detected but not anabaenopeptilide (A). In each sample 1-7 microcystins and up to two anabaenopeptins (anabaenopeptins A and B) were identified. MC-RR and MC-LR were the predominant microcystins, followed by MC-YR. MC-LA and demethylated variants of MC-LR and MC-RR also were present but were not abundant. Total content of microcystin and anabaenopeptin varied from 40 to 2565 microg g(-1) freeze-dried material (mean 674.5 microg g(-1)) and from undetectable to 48 microg g(-1) freeze-dried material (mean 6.2 microg g(-1)), respectively. Qualitative and quantitative variation in the microcystins in the samples indicates there may be geographical trends in the distribution of microcystins. This study reports for the first time (1) the widespread occurrence of several different microcystins in Greek freshwaters and (2) quantitative data on the anabaenopeptins produced in natural cyanobacterial populations.

Isolation and preliminary characterization of cyanobacteria strains from freshwaters of Greece

“…Microcystins were found in 90% of the Microcystis strains examined in this study thus providing further evidence that in Greece cyanobacteria blooms, often dominated by Microcystis spp., are highly likely to contain microcystins [5,19]. ELISA detection of microcystins was in accordance with PCR amplification of the mcy regions, especially the mcyA gene region.…”

“…This is the first report of Limnothrix redekei occurring in Lake Doirani. At the collection dates, water blooms formed mainly by Microcystis spp., Anabaena spp., Aphanizomenon issatschenkoi, and Cylindrospermopsis raciborskii were observed in Kerkini Reservoir and Lakes Cheimaditis, Doirani, Mikri Prespa, Kastoria, and Pamvotis [1,5,19]. All of these genera, with the exception of the benthic Calothrix, are known to occur in Greek lakes [4,6].…”

“…In addition, the HEPF/HEPR primer pair targets the AMT domain of either mcyE or ndaF, involved in the production of MC or nodularin, respectively [33]. Species of the genus Anabaena are well known for microcystin production [34] and are very often one of the dominant bloom-forming species in Greece [4,5,19]. However, the planktic and benthic strains we isolated from Lakes Doirani, Kerkini, and Paralimni seem to be incapable of [35,36] associate marine Synechococcus with MCs.…”

“…In Greece, cyanobacteria diversity and toxicity is mainly known by field (e.g. [4,5,19]) and culture-independent 16S rRNA gene studies (e.g. [7]); only one publication [18] refers to Limnothrix cyanobacteria isolates.…”

Monitoring a newly re-born patient: water quality and cyanotoxin occurrence in a reconstructed shallow Mediterranean lake

“…The warm Mediterranean climate favors cyanobacteria blooms in eutrophic waters, which may start in spring and last until December or even throughout the year in hypertrophic lakes (Cook et al, 2004;. In Greece, extensive CyanoHABs dominated by Microcystis, Dolichospermum (Anabaena), Cylindrospermopsis, Aphanizomenon, Planktothrix, and Limnothrix species occur at eutrophic freshwaters, producing MCs, STX and CYN (Gkelis et al, 2005;2014;2015;Gkelis Advances in Oceanography and Limnology, 2017;8(1): 33-51 ARTICLE DOI: 10.4081/aiol.2017.6350 This work is licensed under a Creative Commons . and Zaoutsos, 2014).…”