Soil cyanobacteria are crucial components of biological soil crusts and carry out many functions in dryland ecosystems. Despite this importance, their taxonomy and population genetics remain poorly known. We isolated 42 strains of simple filamentous cyanobacteria previously identified as Pseudophormidium hollerbachianum from 26 desert locations in the North and South America and characterized these strains using a total evidence approach, that is, using both morphological and molecular data to arrive at taxonomic decisions. Based on a phylogenetic analysis of 16S rRNA gene sequences, we propose and characterize Myxacorys gen. nov. with two new species Myxacorys chilensis, the generitype, and M. californica. We also found distinct 16S‐23S ITS sequence variability within species in our dataset. Especially interesting was the presence of two distinct lineages of M. californica obtained from locations in close spatial proximity (within a few meters to kilometers from each other) suggesting niche differentiation. The detection of such unrecognized lineage‐level variability in soil cyanobacteria has important implications for biocrust restoration practices and conservation efforts.
Stenomitos is a recently established cyanobacterial genus, some species of which appear to be cryptic. Here we describe two new species in this genus, Stenomitos kolaensis sp. nov. isolated from the Al-Fe humic podzols of a boreal forest near Nikel town, Murmansk region, Russia and S. hiloensis sp. nov. isolated from a basaltic seep wall on Akeola Road, Hilo, Hawaii, USA. Phylogenetic analyses were conducted on the 16S and 16S-23S ITS rRNA gene regions using Bayesian Inference, and Maximum Likelihood. Phylogenetic analysis of the 16S-23S ITS rRNA region resulted in both S. kolaensis and S. hiloensis forming separate clades from other Stenomitos lineages. Antarctic strains of Stenomitos frigidus (previously reported as “Leptolyngbya frigida”) show that species to be polyphyletic and in need of revision. The structure of the conserved ITS regions (Box-B, D1-D1ʹ, V2 and V3 helices) provided support for separation of the species, and the p-distances among aligned ITS regions further confirmed that a number of species exist within the genus. S. kolaensis and S. hiloensis can be distinguished from other described Stenomitos species (S. rutilans and S. tremulus) by their geographical distribution, habitat preference, 16S rRNA phylogeny, and differences in the secondary structure of the 16S-23S ITS region.
Two populations of Rivularia-like cyanobacteria were isolated from ecologically distinct and biogeographically distant sites. One population was from an unpolluted stream in the Kola Peninsula of Russia, whereas the other was from a wet wall in the Grand Staircase-Escalante National Monument, a desert park-land in Utah. Though both were virtually indistinguishable from Rivularia in field and cultured material, they were both phylogenetically distant from Rivularia and the Rivulariaceae based on both 16S rRNA and rbcLX phylogenies. We here name the new cryptic genus Cyanomargarita gen. nov., with type species C. melechinii sp. nov., and additional species C. calcarea sp. nov. We also name a new family for these taxa, the Cyanomargaritaceae.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.