title: 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 less than or equal to 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 low- and 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, beta-methylaspartic acid, arginine, N-methyldehydrobutyrine, and 3-amino-9-methoxy-2,6,8-trimethyl-10-phenyl-4,6-decadienoic acid.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Microbiology, University of Helsinki, Finland.
authors.forename: K
authors.initials: K
authors.lastname: Sivonen
authors.forename: K
authors.initials: K
authors.lastname: Kononen
authors.forename: W W
authors.initials: WW
authors.lastname: Carmichael
authors.forename: A M
authors.initials: AM
authors.lastname: Dahlem
authors.forename: K L
authors.initials: KL
authors.lastname: Rinehart
authors.forename: J
authors.initials: J
authors.lastname: Kiviranta
authors.forename: S I
authors.initials: SI
authors.lastname: Niemela
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001681:Biological Assay; D002851:Chromatography, High Pressure Liquid; D000458:Cyanobacteria / Q000254:growth & development*; D005260:Female; D013058:Mass Spectrometry; D051379:Mice; D012623:Seawater; D014118:Toxins, Biological / Q000032:analysis* / Q000633:toxicity; D014871:Water Microbiology
chemical_list: D000596:Amino Acids; D014118:Toxins, Biological