US EPA

6332382 

Journal Article 

Morphological and Molecular Identification of Microcystin-Producing Cyanobacteria in Nine Shallow Bulgarian Water Bodies 

Radkova, M; Stefanova, K; Uzunov, B; Gärtner, G; Stoyneva-Gärtner, M 

2020 

1 

Toxins
ISSN: 2072-6651 

MDPI AG 

12 

1 

English 

31936194 

10.3390/toxins12010039 

WOS:000514630000039 

The paper presents results from the first application of polyphasic approach in studies of field samples from Bulgaria. This approach, which combined the conventional light microscopy (LM) and molecular-genetic methods (based on PCR amplified fragments of microcystin synthetase gene mcyE), revealed that almost all microcystin-producers in the studied eutrophic waterbodies belong to the genus Microcystis. During the molecular identification of toxin-producing strains by use of HEPF × HEPR pair of primers, we obtained 57 sequences, 56 of which formed 28 strains of Microcystis, spread in six clusters of the phylogenetic tree. By LM, seven Microcystis morphospecies were identified (M. aeruginosa, M. botrys, M. flos-aquae, M. natans, M. novacekii, M. smithii, and M. wesenbergii). They showed significant morphological variability and contributed from <1% to 98% to the total biomass. All data support the earlier opinions that taxonomic revision of Microcystis is needed, proved the presence of toxigenic strains in M. aeruginosa and M. wesenbergii, and suppose their existence in M. natans. Our results demonstrated also that genetic sequencing, and the use of HEPF × HEPR pair in particular, can efficiently serve in water quality monitoring for identifying the potential risk from microcystins, even in cases of low amounts of Microcystis in the water. 

Cyanoprokaryotes; Cyanotoxins; Nodularins; Phytoplankton; Polyphasic approach; aminotransferase; microcystin; fresh water; Article; biodiversity; bioinformatics; controlled study; cyanobacterium; gene sequence; genetic analysis; microbial diversity; microbial identification; microbial morphology; Microcystis aeruginosa; Microcystis botrys; Microcystis flosaquae; Microcystis natans; Microcystis novacekii; Microcystis smithii; Microcystis wesenbergii; mucilage; nonhuman; nucleotide sequence; phylogenetic tree; phytoplankton; polymerase chain reaction; sequence analysis; sequence homology; taxonomy; biomass; Bulgaria; Microcystis; phylogeny; Biomass; Bulgaria; Cyanobacteria; Fresh Water; Microcystins; Microcystis; Phylogeny; Polymerase Chain Reaction