The cyanobacterial genus is an important contributor to carbon and nitrogen bioavailability in terrestrial ecosystems and a frequent partner in symbiotic relationships with non-diazotrophic organisms. However, since this currently is a polyphyletic genus, the diversity of -like cyanobacteria is considerably underestimated at this moment. While reviewing the phylogenetic placement of previously isolated -like cyanobacteria originating from Brazilian Amazon, Caatinga and Atlantic forest samples, we detected 17 strains isolated from soil, freshwater, rock and tree surfaces presenting patterns that diverged significantly from related strains when ecological, morphological, molecular and genomic traits were also considered.
View Article and Find Full Text PDFThe saline-alkaline lakes (soda lakes) are the habitat of the haloalkaliphilic cyanobacterium , the type species of this genus. To obtain robust phylogeny of this type species, we have generated whole-genome sequencing of the bloom-forming strain CCIBt3563 isolated from a Brazilian soda lake. This strain presents the typical morphology of with short and curved trichomes with apical heterocytes established after separation of paired intercalary heterocytes and also regarding to cell dimensions.
View Article and Find Full Text PDFFront Microbiol
December 2019
The last decade was marked by efforts to define and identify the main cyanobacterial players in biological crusts around the world. However, not much is known about biocrusts in Brazil's tropical savanna (), despite the existence of environments favorable to their development and ecological relevance. We examined the community composition of cyanobacteria in biocrusts from six sites distributed in the Southeast of the country using high throughput sequencing of 16S rRNA and phylogenetic placement in the wider context of biocrusts from deserts.
View Article and Find Full Text PDFA new Phormidium-like genus was found during an investigation of Oscillatoriales diversity in Brazil. Eight aerophytic populations from south and southeastern regions were isolated in monospecific cultures and submitted to polyphasic evaluation. The populations presented homogeneous morphology with straight trichomes, not attenuated, and apical cell with thickened cell wall.
View Article and Find Full Text PDFTropical ecosystems worldwide host very diverse microbial communities, but are increasingly threatened by deforestation and climate change. Thus, characterization of biodiversity in these environments, and especially of microbial communities that show unique adaptations to their habitats, is a very urgent matter. Information about representatives of the phylum Cyanobacteria in tropical environments is scarce, even though they are fundamental primary producers that help other microbes to thrive in nutrient-depleted habitats, including phyllospheres.
View Article and Find Full Text PDFSeveral new genera originally classified as the genus Phormidium, a polyphyletic and taxonomically complex genus within the Oscillatoriales, were recently described. The simple morphology of Phormidium does not reflect its genetic diversity and the delimitation of a natural group is not possible with traditional classification systems based on morphology alone. Therefore, this study used morphological, ecological, and molecular approaches to evaluate four populations morphologically similar to Ammassolinea, Kamptonema, and Ancylothrix (simple, curved, and gradually attenuated at the ends trichome), found in subtropical and tropical Brazilian regions.
View Article and Find Full Text PDFPhormidium Kützing ex Gomont, a common genus of the Cyanobacteria, is widely known as a problematic group. Its simple morphology is not congruent with its genetic heterogeneity and several new generic entities have been described based on 16S rRNA gene sequence analyses from populations with similar morphology. During a study of the diversity of Phormidioideae (Phormidiaceae, Oscillatoriales) in Brazil, ten Phormidium-like strains from south-eastern and mid-western regions were isolated in monospecific cultures and submitted to polyphasic evaluation (morphological, ecological and molecular studies).
View Article and Find Full Text PDFTwo Cyanobacteria isolated from South Atlantic Ocean continental shelf deep water and from a marine green algae inhabiting the Admiralty Bay, King George Island, Antarctica were investigated based on morphological and ultrastructural traits, phylogeny of 16S rRNA gene sequences, secondary structure of the 16S-23S internal transcribed spacer regions and phylogenomic analyses. The majority of these evaluations demonstrated that both strains differ from the genera of cyanobacteria with validly published names and, therefore, supported the description of the novel genus as Aliterella gen. nov.
View Article and Find Full Text PDFDuring a study about the diversity of Phormidioideae (Phormidiaceae, Oscillatoriales) in Brazil, seven strains from southern and southeastern regions were isolated in monospecifc cultures and submitted to polyphasic evaluation (morphological, ecological, cytological and molecular studies). The populations studied were found to be morphologically similar to Kamptonema (filaments narrowed and bent at the end) and cytologically different (thylakoids' arrangement - radial distribution in Brazilian strains and parietal distribution in Kamptonema). The original habitats were very diverse among the Brazilian strains (freshwater, wet soil and barks of trees).
View Article and Find Full Text PDFThe novel chroococcalean cyanobacterium strain CENA595 was isolated from the deep chlorophyll maximum layer of the continental shelf of the South Atlantic Ocean. Here, we report the draft genome sequence for this strain, consisting of 60 contigs containing a total of 5,265,703 bp and 3,276 putative protein-coding genes.
View Article and Find Full Text PDFAerophytic cyanobacteria are commonly found growing on rocks, tree trunks and soil, but the diversity of these organisms is still poorly known. This complex group is very problematic considering the taxonomic arrangement and species circumscription, especially when taking into account tropical populations. In this work, 20 samples of aerophytic cyanobacteria from 15 distinct sampling sites were collected along a tropical rainforest area at the São Paulo State (Brazil).
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