Molecular and cytomorphological characterization of <i>Pseudanabaena vesniana</i> sp. nov. and <i>Pseudanabaena suomiensis</i> var. <i>macedonica</i> var. nov. (Pseudanabaenales, Cyanobacteriota) with evidence of microcystin‐producing <i>Pseudanabaena</i> taxa
Journal
Journal of Phycology
Date Issued
2025-08-14
Author(s)
Aleksovski, Boris
Saraf, Aniket
Stefanoska, Evgenija
Kiprijanovska, Sanja
Vuchurević, Ana
Pakovski, Kiril
Gugger, Muriel
Krstić, Svetislav
DOI
https://doi.org/10.1111/jpy.70064
Abstract
Detailed molecular and cytomorphological characterization of two toxic
Pseudanabaena strains (NMCCC 011 and NMCCC 012), isolated from
highly polluted shallow areas of Monospitovo Marsh (North Macedonia), was
performed using a “polyphasic” approach. This involved morphological and
ultrastructural characterization, phylogenetic assessment of the 16S rRNA
gene, analyses of the 16S–23S internal transcribed spacer (ITS) rRNA region,
and investigations of the mcyB gene. The 16S rRNA gene phylogenetic analysis
and the ITS rRNA region analyses confirmed that strain NMCCC 011 was a
novel species for which we have proposed the name Pseudanabaena vesniana
sp. nov., whereas NMCCC 012 represented a novel variety of Pseudanabaena
suomiensis, here designated as P. suomiensis var. macedonica. The overall
16S rRNA gene phylogenetic analysis grouped Pseudanabaena into four
large clades. Two of them comprised the primary lineages of diversification,
hosting most Pseudanabaena sensu stricto infrageneric units. Most of these
units formed distinctly recognizable subclades corresponding to different
Pseudanabaena species (Cyanobacteriota); however, some strains were
misidentified, leading to several scattered species through different subclades
within the genus. Additionally, the genus Pseudanabaena was determined to
be polyphyletic, with some strains clustering within the genera Tumidithrix
and Thalassoporum (Cyanobacteriota). The 16S rRNA gene sequence
identity within Pseudanabaena sensu stricto ranged from 95.7% to 99.9%,
while the identity with Tumidithrix, Thalassoporum, and Thermostichus
(Cyanobacteriota) ranged from 87.6% to 92.0%. Furthermore, both strains
NMCCC 011 and NMCCC 012 produced microcystins and 2-methylisoborneol.
The production of microcystins was confirmed by genetic and enzyme-linked
immunosorbent assay (ELISA) analyses. Through this study, we report the
presence of the mcyB gene in Pseudanabaena.
Pseudanabaena strains (NMCCC 011 and NMCCC 012), isolated from
highly polluted shallow areas of Monospitovo Marsh (North Macedonia), was
performed using a “polyphasic” approach. This involved morphological and
ultrastructural characterization, phylogenetic assessment of the 16S rRNA
gene, analyses of the 16S–23S internal transcribed spacer (ITS) rRNA region,
and investigations of the mcyB gene. The 16S rRNA gene phylogenetic analysis
and the ITS rRNA region analyses confirmed that strain NMCCC 011 was a
novel species for which we have proposed the name Pseudanabaena vesniana
sp. nov., whereas NMCCC 012 represented a novel variety of Pseudanabaena
suomiensis, here designated as P. suomiensis var. macedonica. The overall
16S rRNA gene phylogenetic analysis grouped Pseudanabaena into four
large clades. Two of them comprised the primary lineages of diversification,
hosting most Pseudanabaena sensu stricto infrageneric units. Most of these
units formed distinctly recognizable subclades corresponding to different
Pseudanabaena species (Cyanobacteriota); however, some strains were
misidentified, leading to several scattered species through different subclades
within the genus. Additionally, the genus Pseudanabaena was determined to
be polyphyletic, with some strains clustering within the genera Tumidithrix
and Thalassoporum (Cyanobacteriota). The 16S rRNA gene sequence
identity within Pseudanabaena sensu stricto ranged from 95.7% to 99.9%,
while the identity with Tumidithrix, Thalassoporum, and Thermostichus
(Cyanobacteriota) ranged from 87.6% to 92.0%. Furthermore, both strains
NMCCC 011 and NMCCC 012 produced microcystins and 2-methylisoborneol.
The production of microcystins was confirmed by genetic and enzyme-linked
immunosorbent assay (ELISA) analyses. Through this study, we report the
presence of the mcyB gene in Pseudanabaena.