Phylogenetic position of Geitleribactron purpureum (Synechococcales, Cyanobacteria / Cyanophyceae) and its implications for the taxonomy of Chamaesiphonaceae and Leptolyngbyaceae

Abstract

Over the last decades, the taxonomy of cyanobacteria has been considerably improved and restructured due to the increase in data output from molecular phylogeny. Recently, a new protocol was developed that enables reliable sequencing of 16S rRNA genes in cultivation-resistant cyanobacteria using analysis of single cells, filaments, or colonies. In the current study, we examined a sample of a heteropolar unicellular cyanobacterium, Geitleribactron purpureum, from the holotype material (deep epilithon of Lake Tovel, Western Dolomites, Italy). We isolated and purified single colonies of G. purpureum, and subjected them to direct PCR and 16S rRNA gene sequencing. We obtained a congruent set of sequences that formed a unique, isolated cyanobacterial lineage, showing phylogenetic clustering among simple filamentous genera of the family Leptolyngbyaceae. We provide evidence for deep polyphyly in Chamaesiphonaceae, and suggest that Geitleribactron should be re-classified in the Leptolyngbyaceae.

Single colony genetic analysis of epilithic stream algae of the genus Chamaesiphon spp.

“…This is at least partly because rather few strains have been cultivated. Cultivation-independent methods such as the genetic analysis of single colonies of morphospecies can provide an alternative, which has been used successfully in the past (Mareš et al, 2015; Mareš & Cantonati, 2016). During the isolation procedure under the light microscope, associated taxa growing on and between Chamaesiphon colonies were observed (e.g., Homoeothrix varians ), however, not recognized from 16S rDNA sequences obtained from purified Chamaesiphon colonies using the cyanobacteria-specific primers from Taton et al (2003).…”

“…The sequence similarity was calculated using the PHYLIP package (version 3.69, Felsenstein, 2004). All obtained 16S rDNA sequences (1149–1176 bp) were included in a phylogenetic tree constructed from previously described cyanobacterial taxa comprising all major lineages of the phylum (Wilmotte & Herdmann, 2001) as well as clades found related to Chamaesiphon more recently (Bohunická et al, 2015; Mareš & Cantonati, 2016). In total, 150 non-redundant sequences obtained from strains were downloaded from the Ribosomal Database Project (RDP), Cole et al, 2014 (Table S3).…”

“…Chen et al, 2016). Combining the field-based techniques with advanced molecular biological methods holds great potential to analyze the ecological, as well as phylogenetic, diversification of cyanobacteria, particularly if they are difficult to cultivate (e.g., Mareš & Cantonati, 2016). In general, a detailed molecular resolution of Chamaesiphon morphospecies might allow a better characterization of running water habitats that are under environmental stress induced by regional climate change or by anthropogenic influence (e.g., Loza et al, 2013).…”

Growing older, growing more diverse: sea turtles and epibiotic cyanobacteria

“…BBD-AO-Red) is found to be connected to black band disease of corals worldwide (Buerger et al 2016). Another core ASV was identified either as Copelandiella yellostonensis (Kaštovský et al 2023), known as mat forming thermophilic cyanobacterium cryptic to Leptolyngbya or Geitleribactron purpureum, unicellular and heteropolar cyanobacterium that forms purple biofilms on rocks (Cantonati et al 2014) from Leptolyngbyaceae family (Mareš and Cantonati 2016).…”

Neotypification of Pleurocapsa fuliginosa and epitypification of P. minor (Pleurocapsales): resolving a polyphyletic cyanobacterial genus

“…a particularly problematic genus is Pleurocapsa thuret in hauck (1885: 515), which has been attributed to many strains deposited in culture collections all over the world, of which many have been sequenced. however, in DNa based phylogenies these strains intermix with sequences assigned to Chroococcidiopsis, Hyella Bornet & Flahault (1888: 162) , Myxosarcina Printz (1921: 35) , Stanieria Komárek & anagnostidis (1986: 208), Xenococcus thuret in Bornet & thuret (1880: 73, 74) , and Dermocarpella lemmermann (1907: 349) (Ishida et al 2001, Mareš & Cantonati 2016, oliveira alvarenga et al 2016.…”