Emendation of the Coccoid Cyanobacterial Genus Gloeocapsopsis and Description of the New Species Gloeocapsopsis diffluens sp. nov. and Gloeocapsopsis dulcis sp. nov. Isolated From the Coastal Range of the Atacama Desert (Chile)

Abstract

The taxonomy of coccoid cyanobacteria, such as Chroococcidiopsis, Pleurocapsa, Chroococcus, Gloeothece, Gloeocapsa, Gloeocapsopsis, and the related recent genera Sinocapsa and Aliterella, can easily be intermixed when solely compared on a morphological basis. There is still little support on the taxonomic position of some of the addressed genera, as genetic information is available only for a fraction of species that have been described solely on morphology. Modern polyphasic approaches that combine classic morphological investigations with DNA-based molecular analyses and the evaluation of ecological properties can disentangle these easily confusable unicellular genera. By using such an approach, we present here the formal description of two novel unicellular cyanobacterial species that inhabit the Coastal Range of the Atacama Desert, Gloeocapsopsis dulcis (first reported as Gloeocapsopsis AAB1) and Gloeocapsopsis diffluens. Both species could be clearly separated from previously reported species by 16S rRNA and 16S–23S ITS gene sequencing, the resulting secondary structures, p-distance analyses of the 16S–23S ITS, and morphology. For avoiding further confusions emendation of the genus Gloeocapsopsis as well as epitypification of the type species Gloeocapsopsis crepidinum based on the strain LEGE06123 were conducted.

Opening the Gap: Rare Lichens With Rare Cyanobionts – Unexpected Cyanobiont Diversity in Cyanobacterial Lichens of the Order Lichinales

“…Three separate alignments were prepared: one to give a state-of-the-art overview about all orders, a second one depicting the most recent in-depth phylogeny of the Nostocales, and a third one simulating the proposed monophyly of the order Chroococcidiopsidales (Komárek et al, 2014) by excluding complete 16S rRNA gene sequences of specific Oscillatoriales that split some genera within the Chroococcidiopsidales. This specific split was previously detected by Wang et al (2019) and Jung et al (2021) and is induced by the 16S rRNA gene sequences of Cephalothrix lacustris, Aerosakkonema funiforme, and Microseira wollei as well as the Oscillatoriales "core group" including members of the genera Wilmottia, Microcoleus, and related taxa.…”

“…In general, Figure 1 depicts the most recent cyanobacterial phylogeny based on 16S rRNA gene sequences comparable to those presented by Wang et al (2019) or Jung et al (2021).…”

“…The 16S-23S ITS gene region was amplified by PCR in a 50-µl reaction using the primers Wil1 and Wil18 (Wilmotte et al, 1993) and ready-to-go PCR mini beads (GE Healthcare) as described in Jung et al (2021). The quality of the PCR products was checked by means of agarose gel electrophoresis using 1% (w/v) agarose and subsequently purified with NucleSpin Gel and PCR Cleanup Kit (Macherey-Nagel GmbH & Co. KG, Düren, Germany) following the DNA and PCR cleanup protocol.…”

“…The genus Chroococcidiopis is the basis of the order Chroococcidiopsidales whose members often have characteristics of true extremophiles living in hot and cold deserts. Among them are genera such as Chroococcidiopsis, Gloeocapsopsis, and Aliterella occurring in deserts (Büdel, 1999;Jung et al, 2019Jung et al, , 2021 and being extremely desiccation tolerant (Azua-Bustos et al, 2014). They even have been proposed as model organisms for the colonization of Mars (Billi et al, 2019;de Vera et al, 2019;Mosca et al, 2019).…”

“…However, the taxonomic and phylogenetic positions of Chroococcidiopsis spp. were recently questioned (Wang et al, 2019;Jung et al, 2021) due to emerging evidence that the order appears to be perplexed. The underlying study would like to further close the knowledge gap of unicellular cyanobionts by elucidating isolated photobionts of three lichen specimens from the genera Peltula (Australia and South Africa), two of Gonohymenia (Canary Islands, Spain and Czechia), one of Peccania (Austria), and one from Lichinella (Canary Islands, Spain), following the polyphasic approach as well as additional analyses.…”