Is the First Genetically Proved Anatoxin A Producer in Bulgarian Lakes and Reservoirs.

The paper presents the first proof of planktonic cyanoprokaryote genus as an anatoxin A (ATX) producer in Bulgarian wetlands. The results from polymerase chain reaction (PCR) obtained from two summer sampling campaigns in 26 selected lakes and reservoirs demonstrated presence of the gene, responsible for ATX production in 21 strains of the genus. They were found in three waterbodies sampled in 2018 (coastal lake Vaya, coastal reservoir Poroy, inland reservoir Sinyata Reka) and in four waterbodies sampled in 2019 (inland reservoirs Duvanli, Koprinka, Plachidol 2, Sinyata Reka). The detected genetic diversity generally corresponds to the observations conducted by conventional light microscopy, by which we distinguished three species of (, and , the latter considered alien in the country). Eleven strains showed high similarity to two sequences of available from the National Centre for Biotechnology Information (NCBI). Ten other strains assembled in a group, which-in lack of available from NCBI genetic sequences-were presumed related to and after comparison with the results from light microscopy. strains found in Bulgarian waterbodies showed high genetic similarity to those isolated and sequenced from Asia (Japan, China) and Northern Europe (Norway, Finland).