First Data on Cyanotoxins and Genes of Their Biosynthesis in the Phytoplankton of the Mesotrophic Lake Pleshcheyevo (Russia) during the Bloom Formation of Cyanobacterium Gloeotrichia echinulata

Abstract Data on cyanobacterial toxins and the genes of their biosynthesis in the phytoplankton of the mesotrophic Lake Pleshcheyevo (Yaroslavl oblast) during the blooming period of cyanobacterium Gloeotrichia echinulata (Smith et Sowebry) Richter are given for the first time. In the phytoplankton of the lake, the presence of hepatotoxins of microcystins (MC) was recorded using chromatography – mass spectrometry; in DNA isolated from plankton, the mcyE gene for the biosynthesis of these cyanotoxins was detected using PCR. No other types of cyanotoxins (cylindrospermopsin, anatoxin - a, and saxitoxins) or the presence of genes for their synthesis in the phytoplankton are identified during the study period. MC biosynthesis genes mcyA and mcyE were absent in thirty colonies of Gloeotrichia echinulata isolated from the lake, which is consistent with their inability to produce cyanotoxin. Using molecular methods, the potential ability to biosynthesize MC in Microcystis aeruginosa and species of the genus Dolichospermum inhabiting in the lake is demonstrated. This paper discusses the toxicity of Gloeotrichia echinulata and the need for the further long-term monitoring of toxigenic cyanobacteria in Lake Pleshcheyevo.