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The morphological plasticity of cyanobacteria and their widespread ecological dominance in a wide range of habitats highlights the need for in-depth taxonomic studies. This work focused on the taxonomical revision of Leptolyngbya (Cyanophyceae) strains deposited in the ESSACC culture collection and their metabolomic characterization. Although the studied ESSACC strains were morphologically identified as Leptolyngbya sp., the 16S rRNA gene and 16S–23S rRNA ITS analysis revealed that two strains (LMECYA 079 and LMECYA 173) belong to Haloleptolyngbya and represent a new taxonomical unit, genetically unique, ecologically plastic and adapted to both freshwater and thermal habitats, here described as Haloleptolyngbya lusitanica sp. nov. To perform a suspect screening of cyanometabolites in these strains, we used a non-targeted liquid chromatography-high resolution mass spectrometry (LC-HRMS) metabolomic approach. Several metabolites were identified in Haloleptolyngbya lusitanica: micropeptin MM978, spumigin 640, oscillatoxin A and anabaenopeptin D. Strains were maintained and grown under the same conditions, revealing the common production of oscillatoxin A by both H. lusitanica strains. Other identified metabolites, however, were strain-specific, such as anabaenoptin D, which was only detected in LMECYA 173. The different cyanometabolite profiles reinforce the notion that cyanobacteria have the ability to adapt to different habitats, which is maintained under long-term culturing conditions. [ABSTRACT FROM AUTHOR]

Knowledge of the tropical terrestrial cyanobacterial flora from the African continent is still limited. Of 31 strains isolated from soil and subaerial samples collected in Lagos State, Nigeria, three were found to be in the Oculatellaceae, including two species in a new genus. Subsequently, isolates from microbial mats in White Sands National Park in New Mexico, United States, and from a rock near the ocean in Puerto Rico, United States, were found to belong to the new genus as well. Cyanobacterial isolates were characterized microscopically, sequenced for the 16S rRNA gene and associated ITS region, and phylogenetically analyzed. Egbenema gen. nov., with three new species, as well as two new species of Albertania were differentiated from all other Oculatellaceae. Both genera belong to a supported clade within the Oculatellaceae that includes Trichotorquatus and Komarkovaea. The two new species of Albertania, A. egbensis and A. latericola, were from the same sample, but were evolutionarily separate based on 16S rRNA gene phylogenies, percent identity below the 98.7% threshold, and ITS rRNA percent dissimilarity >7.0%. Egbenema aeruginosum gen. et sp. nov. was phylogenetically separated from Trichotorquatus and Albertania but was in a clade with other strains belonging to Egbenema. The two Egbenema strains from the United States are here named Egbenema epilithicum sp. nov. and Egbenema gypsiphilum sp. nov. Our results support the hypothesis that further species discoveries of novel cyanobacteria will likely be made in soils and subaerial habitats, as these habitats continue to be studied, both in tropical and temperate biomes. [ABSTRACT FROM AUTHOR]

The Synechococcales is a large cyanobacterial order comprising both unicellular and filamentous forms, with parietal thylakoid arrangement. Previously, this order has been the subject of taxonomic revisions with new families being erected. During studies of the phototrophic communities on the limestone walls of the Old Cathedral of Coimbra (UNESCO monument), a coccoid Aphanocapsa‐like cyanobacterium was isolated. It was characterized using a polyphasic approach, based on morphology, 16S rRNA phylogenetic and phylogenomic analyses, internal transcribed spacer (ITS) secondary structure, and ecology. The 16S rRNA phylogenetic analyses showed that this strain is placed in a separate and highly supported family‐level clade, as part of a large group comprising the families Prochlorococcaceae and Prochlorotrichaceae, with Lagosinema as the closest (although quite distant) taxon. Additionally, the phylogenomic analysis also placed this strain in a separate lineage, situated distantly apart from the family Thermosynechococcaceae, but with strains assigned to Acaryochloris marina MBIC 11017 and Aphanocapsa montana BDHKU210001 as the closest taxa. Based on these data, as well as on the results from the secondary ITS structure, morphology, and ecology, we here propose the establishment of Petrachlorosaceae fam. nov., along with the description of Petrachloros gen. nov. and Petrachloros mirabilis sp. nov. We also address additional considerations regarding some cyanobacterial taxa within the order Synechococcales, which we believe deserve further revisions. [ABSTRACT FROM AUTHOR]

Benthic cyanobacterial mats (BCMs) are conspicuous components of coral reef communities, where they play key ecological roles as primary producers among others. BCMs often bloom and might outcompete neighboring benthic organisms, including reef-building corals. We investigated the cyanobacterial species composition of three BCMs morphotypes from the marginal reef complex of Abrolhos Bank (Southeastern Brazil). Also, we assessed their allelopathic effects on coral zooxanthellae, their susceptibility to herbivory by fish, and their toxicity to brine shrimp nauplii. Morphology and 16S rDNA sequencing unveiled the cyanobacteria Moorena bouillonii, Okeania erythroflocculosa, Adonisia turfae, Leptolyngbya sp., and Halomicronema sp. as components of BCMs from Abrolhos. BCMs cell-free filtrates and extracts exerted an allelopathic effect by reducing the growth of the ex hospite Symbiodinium sp. in culture. BCMs-only treatments remained untouched in field susceptibility assays in contrast to macroalgae only and mixed BCMs-macroalgae treatments that had the macroalgae fully removed by reef fish. Crude aqueous extracts from BCMs were toxic to brine shrimps in acute assays. Besides unveiling the diversity of BCMs consortia in Abrolhos, our results cast some light on their allelopathy, antiherbivory, and toxicity properties. These antagonistic interactions might promote adverse cascading effects during benthic cyanobacteria blooms and in gradual shifts to BCMs-dominated states.

The present study investigated the biofilm organisms growing on selected monuments of the Champaner Pavagadh complex (Gujarat, India), which is a UNESCO World Heritage Site. The cyanobacteria and microalgae were isolated from biofilms collected through non-destructive methods. The identification of these biological organisms was done using micro-morphological characters and confirmed by 16S rRNA gene sequencing. The exopolysaccharide of each of the isolated strains was extracted, hydrolysed and analysed by the HPTLC. Six isolated strains representing five cyanobacteria and one microalga belong to the genera Desmonostoc, Nostoc, Leptolyngbya, Chroococcidiopsis and Asterarcys. The relationships between substrates' specificity of these isolated biofilm organisms and those identified globally were evaluated using maximum parsimony analysis to generate a consensus phylogenetic tree. The five strains of cyanobacteria isolated were closely clustered with cyanobacteria belonging to a tropical region. At the generic level, no relationship between the species and substratum specificity was recorded. The exopolysaccharide analysis of the isolated strains revealed the presence of seven monosaccharides. While glucose was present in all the analysed species, the concentration of either fucose or arabinose was high. The current study presents a novel HPTLC-based method for determination of monosaccharides composition from the extracellular polymeric substances. [ABSTRACT FROM AUTHOR]

Cyanoprokaryotes are widespread organisms, which dominate in different water basins. In the present study, we have investigated the diversity of this group and related physicochemical parameters in 35 standing water basins in Bulgaria. We found 29 cyanoprokaryotic species, which belong to 13 genera from the orders Synechococcales, Spirulinales and Oscillatoriales. The frequency quotient of each species was calculated. Information about the distribution of the identified species and typology of the water basins is also provided.

SUMMARY: The community composition of marine planktonic cyanobacteria in transitional marine habitats can influence its overall contribution to aquatic primary production. To understand distribution patterns of marine planktonic cyanobacterial assemblages, phylogenetic and statistical analyses were undertaken on planktonic cyanobacterial 16S rRNA gene sequences from four transitional marine habitats [Baltic Sea (BL), Monterey Bay (MB), South China Sea (SCS) and Sundarbans (SB)]. Out of 3255 sequences analyzed, only 546 sequences were found to be planktonic cyanobacteria and were considered in this study. Among these, 338 sequences representative of Sundarbans, the world's largest mangrove were generated based on Sanger and Illumina sequencing approaches. Based on 16S rRNA phylogeny, four major taxonomic orders of marine planktonic cyanobacteria were recovered in varying proportions with several novel 16S rRNA sequences in each of the four targeted sites. Members of the order Synechococcales were dominant in all the sites (−94% sequences) while the orders Chroococcales and Oscillatoriales were only detected in SB and SCS sites, respectively. In the phylogenetic tree, sequences representing the major marine picocyanobacterial genus Synechococcus showed overwhelming dominance in SB and they were found in three other sites. Prochlorococcus‐like sequences were found in sizeable number in MB and SCS but were absent in SB and coastal BL. Synechococcus‐like sequences were represented by three major marine clusters (5.1, 5.2, and 5.3). Three novel clades as part of Synechococcus cluster were detected only in SB and one novel clade in BL. The majority of OTUs were found to be exclusive to each site, whereas some were shared by two or more sites as revealed by beta‐diversity analysis. [ABSTRACT FROM AUTHOR]

Cyanobacteria are widely distributed in terrestrial, freshwater and marine environments, and over the past decades have been recognized as a powerful source of bioactive compounds. In this study, some cyanobacterial strains were isolated from samples of seawater, brackish water and tissue of reef benthic invertebrates (zoanthid Protopalythoa variabilis, the sponges Cynachrella sp. and Haliclona sp., the coral Siderastrea stellata, and ascidians), collected at the states of Paraíba and Rio Grande do Norte (Northeast of Brazil), during the period between July 2010 and February 2014. After standard isolation methods, the cultivation of the strains was carried out in acclimatized culture chamber (25 °C) under constant aeration, for 15 days at 12-hour photoperiod, using Conway and BG11 media made with filtered seawater. The cyanobacterial cells were analysed for the microcystin production by the ELISA technique and their ethanolic and methanolic extracts for the antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa by the agar well diffusion method. The detection of the mcyB gene, one of the genes related to the microcystin synthesis, was done by the Polymerase Chain Reaction (PCR) technique. The majority of the eighteen cyanobacterial strains belonged to Synechococcaceae Family. The genera of Synechocystis, Synechococcus and Romeria were represented by ten, six and two strains, respectively. The production of microcystins was observed in five strains belonging to the genus Synechocystis. The presence of mcyB gene was detected in 12 strains of cyanobacteria: Synechocystis (three strains), Synechococcus (six strains) and Romeria (two strains). Only one strain (Synechocystis aquatilis) showed both the microcystin production and the mcyB gene presence. The antibacterial activity was observed for one strain of Romeria gracilis, one strain of Synechocystis aquatilis and two strains of Synechococcus sp. The ethanolic extracts of R. gracilis strain and two Synechococcus spp. strains inhibited the growth of P. aeruginosa. Among methanolic extracts of cyanobacteria, only one strain of S. aquatilis showed activity against S. aureus,and one R. gracilis strain against P. aeruginosa. Some cyanobacterial strains studied were positive for the microcystin production and antibacterial activity against pathogenic bacteria S. aureus and P. aeuruginosa, and may be further explored for additional biotechnological applications. [ABSTRACT FROM AUTHOR]

Cyanoprokaryotes are widespread organisms, which dominate in different water basins. In the present study, we have investigated the diversity of this group and related physicochemical parameters in 35 standing water basins in Bulgaria. We found 29 cyanoprokaryotic species, which belong to 13 genera from the orders Synechococcales, Spirulinales and Oscillatoriales. The frequency quotient of each species was calculated. Information about the distribution of the identified species and typology of the water basins is also provided. [ABSTRACT FROM AUTHOR]

Saline-alkaline lakes are extreme environments that limit the establishment and development of life. The Nhecolândia, a subregion of the Pantanal wetland in Brazil, is characterized by the existence of ~500 saline-alkaline lakes, which support an underexplored and rich diversity of microorganisms. In this study, unicellular and homocytous cyanobacteria from five saline-alkaline lakes were accessed by culture-dependent approaches. Morphological evaluation and analyses of near complete sequences (~1400 nt) of the 16S r RNA genes were applied for phylogenetic and taxonomic placement. This polyphasic approach allowed for the determination of the taxonomic position of the isolated strains into the following genera: Cyanobacterium, Geminocystis, Phormidium, Leptolyngbya, Limnothrix, and Nodosilinea. In addition, fourteen Pseudanabaenales and Oscillatoriales representatives of putative novel taxa were found. These sequences fell into five new clades that could correspond to new generic units of the Pseudanabaenaceae and Phormidiaceae families. [ABSTRACT FROM AUTHOR]

Timaviella Sciuto & Moro is a recently established cryptic genus of cyanobacteria separated from the morphologically close Leptolyngbya due to clear differences in the 16S rRNA gene sequence and the 16S-23S ITS region secondary structure. Conducting research on biological soil crusts in coastal ecotopes of Ukraine and Germany, we repeatedly observed thin filamentous cyanobacteria morphologically corresponding to the common terrestrial species Leptolyngbya edaphica (Elenkin) Anagnostidis & Komárek. Molecular data based on 16S rRNA gene sequence comparison of the original strains of the morphospecies indicated unambiguous assignment to the genus Timaviella . Based on this finding, we proposed the new nomenclatural combination Timaviella edaphica (Elenkin) O.M. Vynogr. & Mikhailyuk in our previous publication. Deeper molecular study of the four original strains which were morphologically identified as T . edaphica based on the 16S rRNA gene concatenated with the 16S-23S ITS region and 16S-23S ITS secondary structure analysis showed that they are not identical. Three of them (isolated from biocrusts of Black Sea coast and forest path near Kyiv, Ukraine) had high similarity both in 16S rRNA (99.7-100%) and 16S-23S ITS (99.8-100%) hence actually representing T . edaphica . The strain Us-6-3 isolated from biocrusts on sand dunes of Usedom Island in the Baltic Sea, Germany, differs both from original strains of T . edaphica and all published Timaviella species in 16S rRNA gene sequence identity, as well as in sequence and structure of the 16S-23S ITS region. Here we describe Timaviella dunensis sp. nov . and give an expanded description of T . edaphica based on morphological and molecular features. A tabular review of Timaviella species with data on their phenotypic and genotypic features, ecology and distribution is included.

A new cyanobacterium, Patagonifilum jurassicum nov. gen. et sp., is structurally preserved in Late Jurassic hydrothermally influenced siliceous chert from the Deseado Massif, Patagonia, Argentina. The cyanobacterium occurs in the form of loosely to densely spaced, heteropolar filaments (up to 4.5 μm wide) that form turf-like stands, or spherical to hemispherical colonies on different substrates, usually degraded plant stems. Filaments consist of barrel-shaped cells enveloped in a non-stratified sheath, and basal cells that are distinct. The fossil is similar to certain present-day members of the Oscillatoriales (e.g., Homoeothrix), Synechococcales (e.g., Tapinothrix), and Nostocales (e.g., Rivularia , Gloeotrichia). Associated with the cyanobacteria are spheroidal to ovoid vesicles, up to 45 μm in diameter, which occur singly or clustered, mostly near the base of the filaments. They resemble certain present-day zoosporic fungi, and algae, coccoid cyanobacteria, and possibly certain arthropod eggs; however, their systematic affinities remain unresolved. This discovery is nevertheless important because it suggests that the cyanobacterial overgrowths from the Patagonian Jurassic cherts were not monospecific, but rather comprised different organisms that perhaps even interacted with each other. • Soft-bodied microorganisms from Jurassic Lagerstätten in Patagonia. • Three-dimensionally preserved microorganisms in siliceous chert in paleo hot-springs. • First record of three-dimensionally silicified cyanobacteria from the Jurassic. • A new form genus and species and associated microorganisms described. • Key reference on Mesozoic cyanobacterial morphological diversity and interactions. [ABSTRACT FROM AUTHOR]

• Novel Synechococcales genera; Rhodoploca , Cymatolege , Metis , Thalassoporum , Aegeococcus. • Seven new Synechococcales species; five filamentous and two coccoid. • A new pleurocapsalean species Xenococcus spongiosum ; distinct phylogeny and ecology. • High diversity of sponge-associated cyanobacteria. Cyanobacteria are often reported as abundant components of the sponge microbiome; however their diversity below the phylum level is still underestimated. Aiming to broaden our knowledge of sponge-cyanobacteria association, we isolated cyanobacterial strains from Aegean Sea sponges in previous research, which revealed high degree of novel cyanobacterial diversity. Herein, we aim to further characterize sponge-associated cyanobacteria and re-evaluate their classification based on an extensive polyphasic approach, i.e. a combination of molecular, morphological and ecological data. This approach resulted in the description of five new genera (Rhodoploca , Cymatolege , Metis , Aegeococcus , and Thalassoporum) and seven new species (R. sivonenia , C. spiroidea , C. isodiametrica , M. fasciculata , A. anagnostidisi , A. thureti , T. komareki) inside the order Synechococcales, and a new pleurocapsalean species (Xenococcus spongiosum). X. spongiosum is a baeocyte-producing species that shares some morphological features with other Xenococcus species, but has distinct phylogenetic and ecological identity. Rhodoploca , Cymatolege , Metis and Thalassoporum are novel well supported linages of filamentous cyanobacteria that possess distinct characters compared to their sister taxa. Aegeococcus is a novel monophyletic linage of Synechococcus -like cyanobacteria exhibiting a unique ecology, as sponge-dweller. The considerable number of novel taxa characterized in this study highlights the importance of employing polyphasic culture-dependent approaches in order to reveal the true cyanobacterial diversity associated with sponges. [ABSTRACT FROM AUTHOR]