Occurrence of the hepatotoxic cyanobacterium Nodularia spumigena in the Baltic Sea and structure of the toxin

Abstract

Water blooms formed by potentially toxic species of cyanobacteria are a common phenomenon in the Baltic Sea in late summer. Twenty-five cyanobacterial bloom samples were collected from open and coastal waters of the Baltic Sea during 1985 to 1987, and their toxicity was determined by mouse bioassay. All of 5 bloom samples from the southern Baltic Sea, 6 of 6 from the open northern Baltic Sea (Gulf of Finland), and 7 of 14 Finnish coastal samples were found to contain hepatotoxic cyanobacteria. Nodularia spumigena and Aphanizomenon flos-aquae occurred together in high amounts in blooms from the open-sea areas. In addition, coastal samples contained the species Anabaena lemmermannii, Microcystis aeruginosa, and Oscillatoria agardhii. Eighteen hepatotoxic N. spumigena cultures were isolated from water bloom and open-sea water samples. High-pressure liquid chromatographic analysis of both hepatotoxic bloom samples and Nodularia strains showed a single toxic fraction. The toxin concentrations of the blooms were .2.4 mg/g of freeze-dried material, and those of laboratory-grown cultures were 2.5 to 8.0 mg/g of freeze-dried cells. A single toxin was isolated from three N. spumigena-containing bloom samples and three N. spumigena laboratory isolates. Amino acid analysis and lowand high-resolution fast-atom bombardment mass spectroscopy indicated that the toxin from all of the sources was a cyclic pentapeptide (molecular weight, 824) containing glutamic acid, I-methylaspartic acid, arginine, N-methyldehydrobutyrine, and 3-amino-9-methoxy-2,6,8-trimethyl-10-phenyl-4,6-decadienoic acid. This indicates that the Baltic Sea toxin is nodularin, the cyclic pentapeptide produced by field and laboratory-cultured N. spumigena previously reported from New Zealand brackish water lakes. The signs of poisoning by the pentapeptide were similar to those reported for the heptapeptide toxins from other cyanobacteria.

Meta‐omic analyses of Baltic Sea cyanobacteria: diversity, community structure and salt acclimation

“…Likewise, the conspicuous toxin-producing freshwater cyanobacterial genus, Microcystis, was only detected in the metagenomic dataset and in low numbers throughout the Baltic Sea transect. This genus may however still be locally and temporarily abundant in the Baltic Sea (Sivonen et al, 1989;Belykh et al, 2013). Such low-abundance genera may potentially represent 'seed-banks' of rare species in the Baltic Sea.…”

Microbiological, molecular biological and stable isotopic evidence for nitrogen fixation in the open waters of Lake Michigan

“…1997; Sellner, 1997;Wasmund, 1997). These blooms may be toxic as a result of the production of the hepatotoxin nodularin (Paerl, 1988;Sivonen et al, 1989;Paerl and Millie, 1996;Heresztyn and Nicholson, 1997;Sellner, 1997).…”

GENETIC, MORPHOLOGICAL, AND TOXICOLOGICAL VARIATION AMONG GLOBALLY DISTRIBUTED STRAINS OF NODULARIA (CYANOBACTERIA)

“…Nodularia is more widely known from the most commonly reported species, N. spumigena, which forms extensive hepatotoxic blooms in coastal areas around the world. Blooms have been recorded in southern Australian coastal lakes and lagoons (Lukatelich and McComb 1986, Baker and Humpage 1994, Jones et al 1994; inland alkaline, brackish lakes in Australia (Hammer 1981) and North America (Galat et al 1990); the Baltic Sea (Sivonen et al 1989, Kononen 1992 and North Sea coastal lakes (Nehring 1993); and the coastal, brackish Lake Ellesmere in New Zealand (Carmichael et al 1988). The toxin produced by N. spumigena is a cyclic pentapeptide hepatotoxin called nodularin (NODLN), a potent protein phosphatase 1 and 2A inhibitor (Carmichael 1992, Rhinehart et al 1994.…”