Polyphasic approach using multilocus analyses supports the establishment of the new aerophytic cyanobacterial genus Pycnacronema (Coleofasciculaceae, Oscillatoriales)

Abstract

A new Phormidium-like genus was found during an investigation of Oscillatoriales diversity in Brazil. Eight aerophytic populations from south and southeastern regions were isolated in monospecific cultures and submitted to polyphasic evaluation. The populations presented homogeneous morphology with straight trichomes, not attenuated, and apical cell with thickened cell wall. Phylogenetic analyses based on 16S rRNA gene sequences showed that these populations, plus the Brazilian strain Phomidium sp. B-Tom from GenBank, formed a highly supported and distinctive clade, which corresponds to the new genus Pycnacronema, comprising six new species: P. brasiliensis (type species), P. arboriculum, P. conicum, P. marmoreum, P. rubrum, and P. savannensis. These results were confirmed and supported by rpoC1 and rbcL genes evaluated independently and by the concatenated analysis of 16S rRNA, rpoC1 and rbcL genes (for all species but P. savannensis). Secondary structures of the D1-D1 0 , box-B, and V3 regions of the internal transcribed spacer were informative at specific level, being conserved in P. brasiliensis and variable among the other strains, also confirming the phylogenetic analyses. The generic name and specific epithets of the new taxa are proposed under the provisions of the International Code of Nomenclature of algae, fungi, and plants.

Revealing the species diversity of Neolyngbya (Cyanobacteria, Oscillatoriales) from subtropical coastal regions of Okinawa, Japan, with descriptions of Neolyngbya intertidalis sp. nov. and Neolyngbya latusa sp. nov.

“…Several recent taxonomic studies have utilized both the phylogeny and secondary structure of the ITS region to describe new species of cyanobacteria (Mühlsteinov a et al 2014;Vaz et al 2014). Our results confirm that ITS region is an informative genetic marker for cyanobacterial species delineation (Martins et al 2019).…”

“…Our results confirm that ITS region is an informative genetic marker for cyanobacterial species delineation (Martins et al . 2019).…”

The Compositionally Distinct Cyanobacterial Biocrusts From Brazilian Savanna and Their Environmental Drivers of Community Diversity

“…A second complex of biocrust cyanobacteria corresponds to the epithet "Microcoleus steenstrupii" which has been recognized as a supra-generic entity in need of re-evaluation, not only because its members are not related to M. vaginatus (Vaucher) Gomont ex Gomont (the type species for the genus Microcoleus, which falls within the Complex Filamentous clade of Figure 3), but also because it encompasses a variety of separated clades with apparently diverging ecological traits (Fernandes et al, 2018). Sensu lato, the complex also includes sequences aligned with cultured strains assigned to M. paludosus Gomont, and the recently described Pycnacronema savannensis Martins, Machadode-Lima, and Branco isolated and described from Brazilian savanna biocrusts (Martins et al, 2019). All these cyanobacteria are morphologically indistinguishable from Phormidium, except for the fact that they often form trichome bundles.…”

Coleofasciculaceae, a Monophyletic Home for the Microcoleus steenstrupii Complex and Other Desiccation‐tolerant Filamentous Cyanobacteria

“…2011) were described from ephemeral streams, and the rest, including Porphyrosiphon (Gomont 1892), Pycnacronema (Martins et al. 2019), and all taxa newly described herein, are typical soil cyanobacteria. To accommodate as much as possible the rest of the biodiversity within it, we describe six new genera , Funiculus, Parifilum, Arizonema, Crassifilum, Allocoleopsis , and Crustifilum (Fig.…”