Thainema gen. nov. (Leptolyngbyaceae, Synechococcales): A new genus of simple trichal cyanobacteria isolated from a solar saltern environment in Thailand.

Simple trichal types constitute a group of cyanobacteria with an abundance of novel, often cryptic taxa. Here, we investigated material collected from wet surface-soil in a saline environment in Petchaburi Province, central Thailand. A morphological comparison of the isolated strain with similar known species, as well as its phylogenetic and species delimitation analyses based on the combined datasets of other related organisms, especially simple trichal cyanobacteria, revealed that the material of this study represented an independent taxon.

Tenebriella gen. nov. - The dark twin of Oscillatoria.

Oscillatoria has long been known to be polyphyletic. After recent resequencing of the reference strain for this genus, many Oscillatoria-like groups phylogenetically distant from the type species O. princeps remained unresolved.

Molecular and morphological criteria for revision of the genus Microcoleus (Oscillatoriales, Cyanobacteria).

Ninety-two strains of Microcoleus vaginatus (=nomenclatural-type species of the genus Microcoleus Desmazières ex Gomont) and Phormidium autumnale Trevisan ex Gomont from a wide diversity of regions and biotopes were examined using a combination of morphological and molecular methods. Phylogenies based on the 16S rDNA and 16S-23S ITS (partial) demonstrated that the 92 strains, together with a number of strains in GenBank, were members of a highly supported monophyletic clade of strains (Bayesian posterior probability = 1.0) distant from the species-cluster containing the generitype of Phormidium.

Characterization of freshwater benthic biofilm-forming Hydrocoryne (Cyanobacteria) isolates from Antarctica.

The aims of this work were to study cyanobacterial isolates resembling the genus Hydrocoryne using a combination of morphology and phylogeny of 16S rRNA and nifH sequences and to investigate genes involved in cyanotoxin and protease inhibitor production. Four new cyanobacterial strains, isolated from biofilm samples collected from King George Island, Antarctica, were studied. In terms of morphology, these new strains share traits similar to true Anabaena morphotypes (benthic ones), whereas phylogenetic analysis of their 16S rRNA gene sequences grouped them with the sequence of the type species Hydrocoryne spongiosa (H.

The Primitive Thylakoid-Less Cyanobacterium Gloeobacter Is a Common Rock-Dwelling Organism.

Cyanobacteria are an ancient group of photosynthetic prokaryotes, which are significant in biogeochemical cycles. The most primitive among living cyanobacteria, Gloeobacter violaceus, shows a unique ancestral cell organization with a complete absence of inner membranes (thylakoids) and an uncommon structure of the photosynthetic apparatus. Numerous phylogenetic papers proved its basal position among all of the organisms and organelles capable of plant-like photosynthesis (i.

Molecular clock evidence for survival of Antarctic cyanobacteria (Oscillatoriales, Phormidium autumnale) from Paleozoic times.

Cyanobacteria are well adapted to freezing and desiccation; they have been proposed as possible survivors of comprehensive Antarctic glaciations. Filamentous types from the order Oscillatoriales, especially the species Phormidium autumnale Kützing ex Gomont 1892, have widely diverse morphotypes that dominate in Antarctic aquatic microbial mats, seepages, and wet soils. Currently little is known about the dispersion of cyanobacteria in Antarctica and of their population history.

Moorea producens gen. nov., sp. nov. and Moorea bouillonii comb. nov., tropical marine cyanobacteria rich in bioactive secondary metabolites.

The filamentous cyanobacterial genus Moorea gen. nov., described here under the provisions of the International Code of Botanical Nomenclature, is a cosmopolitan pan-tropical group abundant in the marine benthos.

HETEROGENEITY OF THE CYANOBACTERIAL GENUS SYNECHOCYSTIS AND DESCRIPTION OF A NEW GENUS, GEMINOCYSTIS(1).

The study and revision of the unicellular cyanobacterial genus Synechocystis was based on the type species S. aquatilis Sauv. and strain PCC 6803, a reference strain for this species.

Relationships between the Arctic and the Antarctic cyanobacteria; three Phormidium-like strains evaluated by a polyphasic approach.

Selected strains of filamentous Phormidium-like cyanobacteria isolated from two Arctic regions (Ellesmere Island, High Canadian Arctic and Svalbard) and from Antarctica (Antarctic peninsula, South Shetland Islands and South Orkney Islands) were studied. The polyphasic approach used included phenotypic observations of morphological features and genotypic analyses (restriction fragment length polymorphism of 16S rRNA gene, internal transcribed space, 16S rRNA gene sequence analysis). Although genotypes generally correspond to observed morphotypes, the genetic analyses revealed a high degree of biodiversity that could not be unveiled using solely morphological evaluations.

Phylogenetic and morphological evaluation of the genera Anabaena, Aphanizomenon, Trichormus and Nostoc (Nostocales, Cyanobacteria).

The heterocytous cyanobacteria form a monophyletic group according to 16S rRNA gene sequence data. Within this group, phylogenetic and morphological studies have shown that genera such as Anabaena and Aphanizomenon are intermixed. Moreover, the phylogeny of the genus Trichormus, which was recently separated from Anabaena, has not been investigated.

Distribution of microcystin-producing and non-microcystin-producing Microcystis sp. in European freshwater bodies: detection of microcystins and microcystin genes in individual colonies.

Microcystis is a well-known cyanobacterial genus frequently producing hepatotoxins named microcystins. Toxin production is encoded by microcystin genes (mcy). This study aims (i) to relate the mcy occurrence in individual colonies to the presence of microcystin, (ii) to assess whether morphological characteristics (morphospecies) are related to the occurrence of mcy genes, and (iii) to test whether there are geographical variations in morphospecies specificity and abundance of mcy genes.