| Affiliation: | (1) Technische Universität Berlin, Institute für Chemie, AG Biochemie, Franklinstrasse 29, 10587 Berlin, Germany;(2) Institut Pasteur, Unité des Cyanobactéries, 28 rue du Docteur Roux, 75724 Cedex 15 Paris, France;(3) Humboldt-Universität Berlin, Institut für Biologie und Biochemie, Chausseestrasse 117, 10117 Berlin, Germany;(4) Present address: Department of Chemistry, University of Hawaii at Manao, 2545 McCarthy Mall, Honolulu, HI 96822-2275, USA |
| Abstract: | Cyanobacteria are reported to produce secondary metabolites of which toxic and bioactive peptides are of scientific and public interest. Many peptides are synthesized by the non-ribosomal peptide synthesis pathway and their presence is a stable feature of individual clones. We isolated 18 clonal strains of Planktothrix from a single water sample from lake Maxsee near Berlin and analyzed them by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, HPLC, and PCR for their production of peptides and the presence of microcystin synthetase genes. Microcystins could be detected in seven of the strains with considerable variability of contents and numbers of structural variants. Other known peptides like anabaenopeptins B and E/F, microviridin I, and prenylagaramide B and new variants of known peptide classes like aeruginosins and cyanopeptolins were detected in some strains while lacking in others. The 18 strains represented 15 chemotypes with respect to their peptide patterns. In contrast, all strains were morphologically very similar with respect to cell dimensions and pigmentation. Given the diversity of chemotypes among the randomly selected isolates, an immense diversity of chemotypes in the entire population can be assumed. |
