Morphologic, phylogenetic and chemical characterization of a brackish colonial picocyanobacterium (Coelosphaeriaceae) with bioactive properties

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: Kerstin Häggqvist, Anna Torunska-Sitarz, Agata Błaszczyk, Hanna Mazur-Marzec, Jussi Meriluoto
Publisher: MDPI
Publication year: 2016
Journal: Toxins
Volume number: 8
Issue number: 4
Start page: 1
End page: 17
eISSN: 2072-6651


Abstract


Despite their cosmopolitan distribution, knowledge on cyanobacteria in the family
Coelosphaeriaceae is limited. In this study, a single species culture of a coelosphaeran
cyanobacterium isolated from a brackish rock pool in the Baltic Sea was established. The strain
was characterized by morphological features, partial 16S rRNA sequence and nonribosomal
oligopeptide profile. The bioactivity of fractionated extracts against several serine proteases, as well
as protein-serine/threonine phosphatases was studied. Phylogenetic analyses of the strain suggested
a close relationship with Snowella litoralis, but its morphology resembled Woronichinia compacta.
The controversial morphologic and phylogenetic results demonstrated remaining uncertainties
regarding species division in this cyanobacteria family. Chemical analyses of the strain indicated
production of nonribosomal oligopeptides. In fractionated extracts, masses and ion fragmentation
spectra of seven possible anabaenopeptins were identified. Additionally, fragmentation spectra of
cyanopeptolin-like peptides were collected in several of the fractions. The nonribosomal oligopeptide
profile adds another potential identification criterion in future inter- and intraspecies comparisons
of coelosphaeran cyanobacteria. The fractionated extracts showed significant activity against
carboxypeptidase A and trypsin. Inhibition of these important metabolic enzymes might have
impacts at the ecosystem level in aquatic habitats with high cyanobacteria densities.
Despite their cosmopolitan distribution, knowledge on cyanobacteria in the family Coelosphaeriaceae is limited. In this study, a single species culture of a coelosphaeran cyanobacterium isolated from a brackish rock pool in the Baltic Sea was established. The strain was characterized by morphological features, partial 16S rRNA sequence and nonribosomal oligopeptide profile. The bioactivity of fractionated extracts against several serine proteases, as well as protein-serine/threonine phosphatases was studied. Phylogenetic analyses of the strain suggested a close relationship with Snowella litoralis, but its morphology resembled Woronichinia compacta. The controversial morphologic and phylogenetic results demonstrated remaining uncertainties regarding species division in this cyanobacteria family. Chemical analyses of the strain indicated production of nonribosomal oligopeptides. In fractionated extracts, masses and ion fragmentation spectra of seven possible anabaenopeptins were identified. Additionally, fragmentation spectra of cyanopeptolin-like peptides were collected in several of the fractions. The nonribosomal oligopeptide profile adds another potential identification criterion in future inter- and intraspecies comparisons of coelosphaeran cyanobacteria. The fractionated extracts showed significant activity against carboxypeptidase A and trypsin. Inhibition of these important metabolic enzymes might have impacts at the ecosystem level in aquatic habitats with high cyanobacteria densities.


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