| Abstract [eng] |
This work presents a comprehensive study on the diversity and occurrence of cyanobacteria and their secondary metabolites in the Curonian Lagoon and coastal Baltic Sea. In the study, the ecological and socioecological significance of toxic cyanobacteria blooms as well as the biotechnological potential of cyanometabolites were explored. Phytoplankton analyses of samples collected in the Curonian Lagoon showed frequent occurrence of Aphanizomenon, Dolichospermum/Anabaena, Microcystis, Planktothrix and Woronichinia genera. Of these, Dolichospermum/Anabaena, Microcystis, and Planktothrix agardhii were confirmed by genetic methods as potential MCs producers. The assessment of water quality based on cyanobacteria parameters in the recreational areas of the Lithuanian Baltic Sea coast and Curonian Lagoon indicated a low probability of adverse health effects, with a higher risk in the southernmost part of the Curonian Lagoon. As these two systems are interconnected, the dynamics and structure of cyanobacteria in the Curonian Lagoon have significant impact on diversity and concentrations of cyanotoxins in the coastal areas of the sea. During the comprehensive studies of field samples collected in the Curonian Lagoon, 119 cyanometabolites representing eight different classes of the compounds were detected. Cyanopeptolins and microcystins were found to be most structurally diverse class of cyanopeptides. The observed diversity and considerable variation in rare and potentially new microcystin variants may indicate the presence of different cyanobacteria chemotypes in the lagoon. Bioactivity screening of phytoplankton samples from the Curonian Lagoon confirmed pharmaceutical potential of aquatic microorganisms. The samples were active against antibiotic resistant clinical and environmental bacteria strains, they inhibited serine proteases and reduced the viability of the T47D human breast adenocarcinoma cells. |
