A combined morphological, ultrastructural, molecular, and biochemical study of the peculiar family Gomontiellaceae (Oscillatoriales) reveals a new cylindrospermopsin‐producing clade of cyanobacteria

Abstract

Members of the morphologically unusual cyanobacterial family Gomontiellaceae were studied using a polyphasic approach. Cultured strains of Hormoscilla pringsheimii, Starria zimbabweënsis, Crinalium magnum, and Crinalium epipsammum were thoroughly examined, and the type specimen of the family, Gomontiella subtubulosa, was investigated. The results of morphological observations using both light microscopy and transmission electron microscopy were consistent with previous reports and provided evidence for the unique morphological and ultrastructural traits of this family. Analysis of the 16S rRNA gene confirmed the monophyletic origin of non-marine repre-sentatives of genera traditionally classified into this family. The family was phylogenetically placed among other groups of filamentous cyanobacterial taxa. The presence of cellulose in the cell wall was analyzed and confirmed in all cultured Gomontiellaceae members using Fourier transform infrared spectroscopy and fluorescence microscopy. Evaluation of toxins produced by the studied strains revealed the hepatotoxin cylindrospermopsin (CYN) in available strains of the genus Hormoscilla. Production of this compound in both Hormoscilla strains was detected using high-performance liquid chromatography in tandem with high resolution mass spectrometry and confirmed by positive PCR amplification of the cyrJ gene from the CYN biosynthetic cluster. To our knowledge, this is the first report of CYN production by soil cyanobacteria, establishing a previously unreported CYN-producing lineage. This study indicates that cyanobacteria of the family Gomontiellaceae form a separate but coherent cluster defined by numerous intriguing morphological, ultrastructural, and biochemical features, and exhibiting a toxic potential worthy of further investigation.

Taxonomic resolution of the genus Cyanothece (Chroococcales, Cyanobacteria), with a treatment on Gloeothece and three new genera, Crocosphaera, Rippkaea, and Zehria

“…The clustering of Cyanothece in a special and derived phylogenetic lineage close to filamentous taxa is congruent with previous reports (Bohunická et al. ). This vast evolutionary divergence further highlights the need for designation of suitable taxonomic names for unrelated isolates attributed incorrectly to Cyanothece in culture collections and sequence databases.…”

“…, Bohunická et al. ). Cyanothece aeruginosa is a freshwater to subaerophytic species, typically dwelling in somewhat acidic habitats.…”

Toxic cyanobacteria and cyanotoxins in European waters – recent progress achieved through the CYANOCOST Action and challenges for further research

“…Further, in Hungary in 2002 (Kiss et al, 2002), Italy andSpain in 2004 (Manti et al, 2005;Quesada et al, 2006), Finland, France, the Czech Republic and Poland in 2006 (Spoof et al, 2006;Bláhová et al, 2009;Brient et al, 2009;Kokociński et al, 2009). In Europe, cyanobacteria capable of producing CYN have most often been found in the genera Aphanizomenon, Anabaena/Dolichospermum, Chrysosporum and Oscillatoria Rzymski and Poniedziałek, 2014;Bernard et al, 2017 (Akcaalan et al, 2014;Bohunická et al, 2015). Moreover, Gkelis and Zaoutsos (2014) for the first time reported CYN and a C. raciborskii bloom producing STX in Greece but a definitive identification of the CYN producer could not be made.…”

A revision of the genus Geitlerinema and a description of the genus Anagnostidinema gen. nov. (Oscillatoriophycidae, Cyanobacteria)

“…Fig. 1; Bohunická et al 2015), which is rather curious. Species of the family Gomontiellaceae have distinctively constricted cross walls and they possess special morphology (trichomes not circular in cross-section) among the non-heterocytous, filamentous cyanobacteria (Bohunická et al 2015).…”

“…The rest of the sequences of cyanobacterial strains were added as outgroup taxa for a congruent phylogeny (cf. mareS et al 2013;Bohunická et al 2015).…”