10 results on '"Melainabacteria"'
Search Results
2. Non-Photosynthetic Melainabacteria (Cyanobacteria) in Human Gut: Characteristics and Association with Health.
- Author
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Hu C and Rzymski P
- Abstract
Gut microorganisms are comprised of thousands of species and play an important role in the host's metabolism, overall health status, and risk of disease. Recently, the discovery of non-photosynthetic cyanobacteria (class "Melainabacteria") in the human and animal gut triggered a broad interest in studying cyanobacteria's evolution, physiology, and ecological relevance of the Melainabacteria members. In the present paper, we review the general characteristics of Melainabacteria, their phylogeny, distribution, and ecology. The potential link between these microorganisms and human health is also discussed based on available human-microbiome studies. Their abundance tends to increase in patients with selected neurodegenerative, gastrointestinal, hepatic, metabolic, and respiratory diseases. However, the available evidence is correlative and requires further longitudinal studies. Although the research on Melainabacteria in the human gut is still in its infancy, elucidation of their role appears important in better understanding microbiome-human health interactions. Further studies aiming to identify particular gut cyanobacteria species, culture them in vitro , and characterize them on the molecular, biochemical, and physiological levels are encouraged.
- Published
- 2022
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3. Trends in Free-access Genomic Data Accelerate Advances in Cyanobacteria Taxonomy.
- Author
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Dextro RB, Delbaje E, Cotta SR, Zehr JP, and Fiore MF
- Subjects
- Genomics, Metagenome, Phylogeny, Cyanobacteria genetics, Microbiota
- Abstract
Free access databases of DNA sequences containing microbial genetic information have changed the way scientists look at the microbial world. Currently, the NCBI database includes about 516 distinct search results for Cyanobacterial genomes distributed in a taxonomy based on a polyphasic approach. While their classification and taxonomic relationships are widely used as is, recent proposals to alter their grouping include further exploring the relationship between Cyanobacteria and Melainabacteria. Nowadays, most cyanobacteria still are named under the Botanical Code; however, there is a proposal made by the Genome Taxonomy Database (GTDB) to harmonize cyanobacteria nomenclature with the other bacteria, an initiative to standardize microbial taxonomy based on genome phylogeny, in order to contribute to an overall better phylogenetic resolution of microbiota. Furthermore, the assembly level of the genomes and their geographical origin demonstrates some trends of cyanobacteria genomics on the scientific community, such as low availability of complete genomes and underexplored sampling locations. By describing how available cyanobacterial genomes from free-access databases fit within different taxonomic classifications, this mini-review provides a holistic view of the current knowledge of cyanobacteria and indicates some steps towards improving our efforts to create a more cohesive and inclusive classifying system, which can be greatly improved by using large-scale sequencing and metagenomic techniques., (© 2021 Phycological Society of America.)
- Published
- 2021
- Full Text
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4. Phylogeny and Evolutionary History of Respiratory Complex I Proteins in Melainabacteria.
- Author
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Grettenberger C, Sumner DY, Eisen JA, Jungblut AD, and Mackey TJ
- Subjects
- Bacterial Proteins metabolism, Cyanobacteria classification, Cyanobacteria metabolism, Electron Transport Complex I metabolism, Bacterial Proteins genetics, Cyanobacteria genetics, Electron Transport Complex I genetics, Evolution, Molecular, Phylogeny
- Abstract
The evolution of oxygenic photosynthesis was one of the most transformative evolutionary events in Earth's history, leading eventually to the oxygenation of Earth's atmosphere and, consequently, the evolution of aerobic respiration. Previous work has shown that the terminal electron acceptors (complex IV) of aerobic respiration likely evolved after the evolution of oxygenic photosynthesis. However, complex I of the respiratory complex chain can be involved in anaerobic processes and, therefore, may have pre-dated the evolution of oxygenic photosynthesis. If so, aerobic respiration may have built upon respiratory chains that pre-date the rise of oxygen in Earth's atmosphere. The Melainabacteria provide a unique opportunity to examine this hypothesis because they contain genes for aerobic respiration but likely diverged from the Cyanobacteria before the evolution of oxygenic photosynthesis. Here, we examine the phylogenies of translated complex I sequences from 44 recently published Melainabacteria metagenome assembled genomes and genomes from other Melainabacteria, Cyanobacteria, and other bacterial groups to examine the evolutionary history of complex I. We find that complex I appears to have been present in the common ancestor of Melainabacteria and Cyanobacteria, supporting the idea that aerobic respiration built upon respiratory chains that pre-date the evolution of oxygenic photosynthesis and the rise of oxygen.
- Published
- 2021
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5. What's in a name? The case of cyanobacteria.
- Author
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Garcia-Pichel F, Zehr JP, Bhattacharya D, and Pakrasi HB
- Subjects
- Carbon Dioxide, Oxygen, Photosynthesis, Phylogeny, Cyanobacteria
- Abstract
A redefinition of the cyanobacterial lineage has been proposed based on phylogenomic analysis of distantly related nonphototrophic lineages. We define Cyanobacteria here as "Organisms in the domain bacteria able to carry out oxygenic photosynthesis with water as an electron donor and to reduce carbon dioxide as a source of carbon, or those secondarily evolved from such organisms.", (© 2019 The Authors. Journal of Phycology published by Wiley Periodicals, Inc. on behalf of Phycological Society of America.)
- Published
- 2020
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6. Long Term Diversity and Distribution of Non-photosynthetic Cyanobacteria in Peri-Alpine Lakes.
- Author
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Monchamp ME, Spaak P, and Pomati F
- Abstract
The phylum Cyanobacteria comprises a non-photosynthetic lineage. The diversity and distribution of non-photosynthetic cyanobacteria (NCY) across aquatic environments are currently unknown, including their ecology. Here, we report about composition and phylogenetic diversity of two clades of NCY in ten lakes of the European peri-Alpine region, over the past ∼100 years. Using 16S rDNA sequences obtained from dated sediment cores, we found almost equal proportion of taxa assigned to Melainabacteria and the deepest-branching group Sericytochromatia (ML635J-21) (63 total detected taxa). The topology of our reconstructed phylogenies reflected evolutionary relationships expected from previous work, that is, a clear separation between the deepest branching Sericytochromatia, the Melainabacteria, and the photosynthetic cyanobacteria clades. While different lakes harbored distinct NCY communities, the diversity of NCY assemblages within and between lakes (alpha and beta diversity) did not significantly change over the last century. This is in contrast with what was previously reported for photosynthetic cyanobacteria. Unchanged community phylogenetic similarity over geographic distance indicated no dispersal limitation of NCY at the regional scale. Our results solicit studies linking in-lake environmental factors to the composition of these microorganisms' communities, whose assembly appeared not to have been influenced by large-scale anthropogenic environmental changes. This is the first attempt to study the diversity and distribution of NCY taxa across temperate lakes. It provides a first step towards understanding their distribution and ecological function in pelagic aquatic habitats, where these organisms seem to be prevalent.
- Published
- 2019
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7. Marine-influenced microbial communities inhabit terrestrial hot springs on a remote island volcano.
- Author
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Stewart LC, Stucker VK, Stott MB, and de Ronde CEJ
- Subjects
- Cyanobacteria isolation & purification, Cyanobacteria metabolism, Hot Springs chemistry, Iron analysis, Iron metabolism, Methane analysis, Methane metabolism, New Zealand, Proteobacteria isolation & purification, Proteobacteria metabolism, Sulfur analysis, Sulfur metabolism, Volcanic Eruptions, Hot Springs microbiology, Microbiota
- Abstract
Raoul Island is a subaerial island volcano approximately 1000 km northeast of New Zealand. Its caldera contains a circumneutral closed-basin volcanic lake and several associated pools, as well as intertidal coastal hot springs, all fed by a hydrothermal system sourced from both meteoric water and seawater. Here, we report on the geochemistry, prokaryotic community diversity, and cultivatable abundance of thermophilic microorganisms of four terrestrial features and one coastal feature on Raoul. Hydrothermal fluid contributions to the volcanic lake and pools make them brackish, and consequently support unusual microbial communities dominated by Planctomycetes, Chloroflexi, Alphaproteobacteria, and Thaumarchaeota, as well as up to 3% of the rare sister phylum to Cyanobacteria, Candidatus Melainabacteria. The dominant taxa are mesophilic to moderately thermophilic, phototrophic, and heterotrophic marine groups related to marine Planctomycetaceae. The coastal hot spring/shallow hydrothermal vent community is similar to other shallow systems in the Western Pacific Ocean, potentially due to proximity and similarities of geochemistry. Although rare in community sequence data, thermophilic methanogens, sulfur-reducers, and iron-reducers are present in culture-based assays.
- Published
- 2018
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8. Back from the dead; the curious tale of the predatory cyanobacterium Vampirovibrio chlorellavorus.
- Author
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Soo RM, Woodcroft BJ, Parks DH, Tyson GW, and Hugenholtz P
- Abstract
An uncultured non-photosynthetic basal lineage of the Cyanobacteria, the Melainabacteria, was recently characterised by metagenomic analyses of aphotic environmental samples. However, a predatory bacterium, Vampirovibrio chlorellavorus, originally described in 1972 appears to be the first cultured representative of the Melainabacteria based on a 16S rRNA sequence recovered from a lyophilised co-culture of the organism. Here, we sequenced the genome of V. chlorellavorus directly from 36 year-old lyophilised material that could not be resuscitated confirming its identity as a member of the Melainabacteria. We identified attributes in the genome that likely allow V. chlorellavorus to function as an obligate predator of the microalga Chlorella vulgaris, and predict that it is the first described predator to use an Agrobacterium tumefaciens-like conjugative type IV secretion system to invade its host. V. chlorellavorus is the first cyanobacterium recognised to have a predatory lifestyle and further supports the assertion that Melainabacteria are non-photosynthetic.
- Published
- 2015
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9. An expanded genomic representation of the phylum cyanobacteria.
- Author
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Soo RM, Skennerton CT, Sekiguchi Y, Imelfort M, Paech SJ, Dennis PG, Steen JA, Parks DH, Tyson GW, and Hugenholtz P
- Subjects
- Animals, Biological Evolution, Cyanobacteria classification, Cyanobacteria isolation & purification, Cyanobacteria metabolism, Feces microbiology, Genetics, Population, Male, Photosynthesis, RNA, Ribosomal, 16S, Waste Disposal, Fluid instrumentation, Waste Disposal, Fluid methods, Bioreactors microbiology, Cyanobacteria genetics, Genome, Bacterial, Phascolarctidae microbiology, Phylogeny
- Abstract
Molecular surveys of aphotic habitats have indicated the presence of major uncultured lineages phylogenetically classified as members of the Cyanobacteria. One of these lineages has recently been proposed as a nonphotosynthetic sister phylum to the Cyanobacteria, the Melainabacteria, based on recovery of population genomes from human gut and groundwater samples. Here, we expand the phylogenomic representation of the Melainabacteria through sequencing of six diverse population genomes from gut and bioreactor samples supporting the inference that this lineage is nonphotosynthetic, but not the assertion that they are strictly fermentative. We propose that the Melainabacteria is a class within the phylogenetically defined Cyanobacteria based on robust monophyly and shared ancestral traits with photosynthetic representatives. Our findings are consistent with theories that photosynthesis occurred late in the Cyanobacteria and involved extensive lateral gene transfer and extends the recognized functionality of members of this phylum.
- Published
- 2014
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10. The human gut and groundwater harbor non-photosynthetic bacteria belonging to a new candidate phylum sibling to Cyanobacteria.
- Author
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Di Rienzi SC, Sharon I, Wrighton KC, Koren O, Hug LA, Thomas BC, Goodrich JK, Bell JT, Spector TD, Banfield JF, and Ley RE
- Subjects
- Anaerobiosis, Cyanobacteria genetics, Fermentation, Genes, Bacterial, Humans, Light, Photosynthesis, Phylogeny, RNA, Ribosomal, 16S genetics, Cyanobacteria classification, Groundwater microbiology, Intestines microbiology
- Abstract
Cyanobacteria were responsible for the oxygenation of the ancient atmosphere; however, the evolution of this phylum is enigmatic, as relatives have not been characterized. Here we use whole genome reconstruction of human fecal and subsurface aquifer metagenomic samples to obtain complete genomes for members of a new candidate phylum sibling to Cyanobacteria, for which we propose the designation 'Melainabacteria'. Metabolic analysis suggests that the ancestors to both lineages were non-photosynthetic, anaerobic, motile, and obligately fermentative. Cyanobacterial light sensing may have been facilitated by regulators present in the ancestor of these lineages. The subsurface organism has the capacity for nitrogen fixation using a nitrogenase distinct from that in Cyanobacteria, suggesting nitrogen fixation evolved separately in the two lineages. We hypothesize that Cyanobacteria split from Melainabacteria prior or due to the acquisition of oxygenic photosynthesis. Melainabacteria remained in anoxic zones and differentiated by niche adaptation, including for symbiosis in the mammalian gut. DOI:http://dx.doi.org/10.7554/eLife.01102.001.
- Published
- 2013
- Full Text
- View/download PDF
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