First Data on Cyanotoxins and Genes of Their Biosynthesis in the Phytoplankton of the Mesotrophic Lake Pleshcheyevo (Russia) During the Bloom Formation of Cyanobacterium <i>Gloeotrichia echinulata</i>

The article presents for the first time the data on cyanobacterial toxins and the genes of their biosynthesis in the phytoplankton of the mesotrophic Lake Pleshcheyevo Yaroslavl Region, during the period of cyanobacterium Gloeotrichia echinulata (Smith et Sowebry) Richter – bloom. In the phytoplankton of the lake, the presence of hepatotoxins microcystins was recorded using chromatography – mass spectrometry; in DNA isolated from plankton, the mcyE gene for the biosynthesis of these cyanotoxins was detected using PCR. During the study period, other types of cyanotoxins (cylindrospermopsin, anatoxin – a, saxitoxins) and the presence of genes for their synthesis in the phytoplankton were not identified. In thirty colonies of G. echinulata isolated from the lake, the microcystin biosynthesis genes mcyA and mcyE were absent, which is consistent with their inability to produce cyanotoxin. Using molecular methods, the potential ability to biosynthesize microcystins in Microcystis aeruginosa and species of the genus Dolichospermum inhabiting in the lake was demonstrated. The paper discusses the toxicity of Gloeotrichia echinulata and the need for further long-term monitoring of toxigenic cyanobacteria in Lake Pleshcheyevo.