49 research outputs found

    Rings Reconcile Genotypic and Phenotypic Evolution within the Proteobacteria.

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    Although prokaryotes are usually classified using molecular phylogenies instead of phenotypes after the advent of gene sequencing, neither of these methods is satisfactory because the phenotypes cannot explain the molecular trees and the trees do not fit the phenotypes. This scientific crisis still exists and the profound disconnection between these two pillars of evolutionary biology--genotypes and phenotypes--grows larger. We use rings and a genomic form of goods thinking to resolve this conundrum (McInerney JO, Cummins C, Haggerty L. 2011. Goods thinking vs. tree thinking. Mobile Genet Elements. 1:304-308; Nelson-Sathi S, et al. 2015. Origins of major archaeal clades correspond to gene acquisitions from bacteria. Nature 517:77-80). The Proteobacteria is the most speciose prokaryotic phylum known. It is an ideal phylogenetic model for reconstructing Earth's evolutionary history. It contains diverse free living, pathogenic, photosynthetic, sulfur metabolizing, and symbiotic species. Due to its large number of species (Whitman WB, Coleman DC, Wiebe WJ. 1998. Prokaryotes: the unseen majority. Proc Nat Acad Sci U S A. 95:6578-6583) it was initially expected to provide strong phylogenetic support for a proteobacterial tree of life. But despite its many species, sequence-based tree analyses are unable to resolve its topology. Here we develop new rooted ring analyses and study proteobacterial evolution. Using protein family data and new genome-based outgroup rooting procedures, we reconstruct the complex evolutionary history of the proteobacterial rings (combinations of tree-like divergences and endosymbiotic-like convergences). We identify and map the origins of major gene flows within the rooted proteobacterial rings (P < 3.6 × 10(-6)) and find that the evolution of the "Alpha-," "Beta-," and "Gammaproteobacteria" is represented by a unique set of rings. Using new techniques presented here we also root these rings using outgroups. We also map the independent flows of genes involved in DNA-, RNA-, ATP-, and membrane- related processes within the Proteobacteria and thereby demonstrate that these large gene flows are consistent with endosymbioses (P < 3.6 × 10(-9)). Our analyses illustrate what it means to find that a gene is present, or absent, within a gene flow, and thereby clarify the origin of the apparent conflicts between genotypes and phenotypes. Here we identify the gene flows that introduced photosynthesis into the Alpha-, Beta-, and Gammaproteobacteria from the common ancestor of the Actinobacteria and the Firmicutes. Our results also explain why rooted rings, unlike trees, are consistent with the observed genotypic and phenotypic relationships observed among the various proteobacterial classes. We find that ring phylogenies can explain the genotypes and the phenotypes of biological processes within large and complex groups like the Proteobacteria

    Assessment of MultiLocus Sequence Analysis As a Valuable Tool for the Classification of the Genus Salinivibrio

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    The genus Salinivibrio includes obligatory halophilic bacteria and is commonly isolated from hypersaline habitats and salted food products. They grow optimally between 7.5 and 10% salts and are facultative anaerobes. Currently, this genus comprises four species, one of them, S. costicola, with three subspecies. In this study we isolated and characterized an additional 70 strains from solar salterns located in different locations. Comparative 16S rRNA gene sequence analysis identified these strains as belonging to the genus Salinivibrio but could not differentiate strains into species-like groups. To achieve finer phylogenetic resolution, we carried out a MultiLocus Sequence Analysis (MLSA) of the new isolates and the type strains of the species of Salinivibrio based on the individual as well as concatenated sequences of four housekeeping genes: gyrB, recA, rpoA, and rpoD. The strains formed four clearly differentiated species-like clusters called phylogroups. All of the known type and subspecies strains were associated with one of these clusters except S. sharmensis. One phylogroup had no previously described species coupled to it. Further DNA–DNA hybridization (DDH) experiments with selected representative strains from these phylogroups permitted us to validate the MLSA study, correlating the species level defined by the DDH (70%) with a 97% cut-off for the concatenated MLSA gene sequences. Based on these criteria, the novel strains forming phylogroup 1 could constitute a new species while strains constructing the other three phylogroups are members of previously recognized Salinivibrio species. S. costicola subsp. vallismortis co-occurs with S. proteolyticus in phylogroup 4, and separately from other S. costicola strains, indicating its need for reclassification. On the other hand, genome fingerprinting analysis showed that the environmental strains do not form clonal populations and did not cluster according to their site of cultivation. In future studies regarding the classification and identification of new Salinivibrio strains we recommend the following strategy: (i) initial partial sequencing of the 16S rRNA gene for genus-level identification; (ii) sequencing and concatenation of the four before mentioned housekeeping genes for species-level discrimination; (iii) DDH experiments, only required when the concatenated MLSA similarity values among a new isolate and other Salinivibrio strains are above the 97% cut-off.España, MINECO project CGL2013- 46941-

    Draft Genome Sequence of Saccharomonospora sp. Strain LRS4.154, a Moderately Halophilic Actinobacterium with the Biotechnologically Relevant Polyketide Synthase and Nonribosomal Peptide Synthetase Systems

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    The draft genome sequence of Saccharomonospora sp. strain LRS4.154, a moderately halophilic actinobacterium, has been determined. The genome has 4,860,108 bp, a G C content of 71.0%, and 4,525 open reading frames (ORFs). The clusters of PKS and NRPS genes, responsible for the biosynthesis of a large number of biomolecules, were identified in the genome

    Draft Genome Sequence of Saccharomonospora piscinae KCTC 19743T, an Actinobacterium Containing Secondary Metabolite Biosynthetic Gene Clusters

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    Artículo científico producto de proyecto de investigación.The draft genome sequence of Saccharomonospora piscinae KCTC 19743T, with a size of 4,897,614 bp, was assembled into 11 scaffolds containing 4,561 open reading frames and a G C content of 71.0 mol%. Polyketide synthase and nonribosomal peptide synthetase gene clusters, which are responsible for the biosynthesis of several biomolecules, were identified and located in different regions in the genome.CONACY

    Draft Genome Sequence of the Moderately Halophilic Bacterium Pseudoalteromonas ruthenica Strain CP76

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    Pseudoalteromonas ruthenica strain CP76, isolated from a saltern in Spain, is a moderately halophilic bacterium belonging to the Gammaproteobacteria. Here we report the draft genome sequence, which consists of a 4.0-Mb chromosome, of this strain, which is able to produce the extracellular enzyme haloprotease CPI

    Draft Genome Sequences of Salinivibrio proteolyticus, Salinivibrio sharmensis, Salinivibrio siamensis, Salinivibrio costicola subsp. alcaliphilus, Salinivibrio costicola subsp. vallismortis, and 29 New Isolates Belonging to the Genus Salinivibrio

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    The draft genome sequences of 5 type strains of species of the halophilic genus Salinivibrio and 29 new isolates from different hypersaline habitats belonging to the genus Salinivibrio have been determined. The genomes have 3,123,148 to 3,641,359 bp, a G+C content of 49.2 to 50.9%, and 2,898 to 3,404 open reading frames (ORFs).España, Ministerio de Ciencia e Innovación CGL2013-46941-

    Characterization of Salinivibrio socompensis sp. nov., A new halophilic bacterium isolated from the high-altitude hypersaline lake Socompa, Argentina

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    The genus Salinivibrio belongs to the family Vibrionaceae and includes Gram-stain-negative, motile by a polar flagellum, and facultatively anaerobic curved rods. They are halophilic bacteria commonly found in hypersaline aquatic habitats and salted foods. This genus includes five species and two subspecies. A presumed novel species, strain S35T, was previously isolated from the high-altitude volcanic, alkaline, and saline lake Socompa (Argentinean Andes). In this study we carried out a complete taxonomic characterization of strain S35T, including the 16S rRNA gene sequence and core-genome analysis, the average nucleotide identity (ANIb, ANIm, and orthoANI), and in silico DNA?DNA hybridization (GGDC), as well as the phenotypic and chemotaxonomic characterization. It grew at 3%?20% (w/v) NaCl, pH 6?10, and 10?42 °C, with optimum growth at 7.0%?7.5% (w/v) NaCl, pH 8.0, and 37 °C, respectively. Strain S35T was oxidase- and catalase-positive, able to produce acid from D-glucose and other carbohydrates. Hydrolysis of DNA, methyl red test, and nitrate and nitrite reduction were positive. Its main fatty acids were C16:0, C16:1 ω7c and C16:1 ω6c, and C18:1 ω7c and/or C18:1 ω6c. ANI, GGDC, and core-genome analysis determined that strain S35T constitutes a novel species of the genus Salinivibrio, for which the name Salinivibrio socompensis sp. nov. is proposed. The type strain is S35T (= CECT 9634T = BNM 0535T)Fil: Galisteo, Cristina. Universidad de Sevilla; EspañaFil: Sánchez Porro,Cristina. Universidad de Sevilla; EspañaFil: de la Haba, Rafael R.. Universidad de Sevilla; EspañaFil: López Hermoso, Clara. Universidad de Sevilla; EspañaFil: Fernández, Ana Belén. Universidad de Sevilla; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Ventosa, Antonio. Department Of Microbiology And Parasitology, Faculty Of; Españ

    Horizontal gene transfer, dispersal and haloarchaeal speciation

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    The Halobacteria are a well-studied archaeal class and numerous investigations are showing how their diversity is distributed amongst genomes and geographic locations. Evidence indicates that recombination between species continuously facilitates the arrival of new genes, and within species, it is frequent enough to spread acquired genes amongst all individuals in the population. To create permanent independent diversity and generate new species, barriers to recombination are probably required. The data support an interpretation that rates of evolution (e.g., horizontal gene transfer and mutation) are faster at creating geographically localized variation than dispersal and invasion are at homogenizing genetic differences between locations. Therefore, we suggest that recurrent episodes of dispersal followed by variable periods of endemism break the homogenizing forces of intrapopulation recombination and that this process might be the principal stimulus leading to divergence and speciation in Halobacteria

    Halorubrum chaoviator mancinelli et al. 2009 is a later, heterotypic synonym of halorubrum ezzemoulense kharroub et al. 2006. emended description of halorubrum ezzemoulense kharroub et al. 2006

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    A polyphasic comparative taxonomic study of Halorubrum ezzemoulense Kharroub et al. 2006, Halorubrum chaoviator Mancinelli et al. 2009 and eight new Halorubrum strains related to these haloarchaeal species was carried out. Multilocus sequence analysis using the five concatenated housekeeping genes atpB, EF-2, glnA, ppsA and rpoB’, and phylogenetic analysis based on the 757 core protein sequences obtained from their genomes showed that Hrr. ezzemoulense DSM 17463 T , Hrr. chaoviator Halo-G* T (=DSM 19316 T ) and the eight Halorubrum strains formed a robust cluster, clearly separated from the remaining species of the genus Halorubrum. The orthoANI value and digital DNA-DNA hybridization value, calculated by the Genome-to-Genome Distance Calculator (GGDC), showed percentages among Hrr. ezzemoulense DSM 17463 T , Hrr. chaoviator DSM 19316 T and the eight Halorubrum strains ranging from 99.4 to 97.9 %, and from 95.0 to 74.2 %, respectively, while these values for those strains and the type strains of the most closely related species of Halorubrum were 88.7-77.4% and 36.1- 22.3 %, respectively. Although some differences were observed, the phenotypic and polar lipid profiles were quite similar for all the strains studied. Overall, these data show that Hrr. ezzemoulense, Hrr. chaoviator and the eight new Halorubrum isolates constitute a single species. Thus, Hrr. chaoviator should be considered as a later, heterotypic synonym of Hrr. ezzemoulense. We propose an emended description of Hrr. ezzemoulense, including the features of Hrr. chaoviator and those of the eight new isolates.Ministerio de Economía y Competitividad CGL2013-46941-P, CGL2017-83385-PNational Science Foundation DEB-0919290, 0830024NASA Astrobiology NNX12AD70G, NNX15AM09

    Draft Genome Sequence of the Moderately Halophilic Bacterium Marinobacter lipolyticus Strain SM19

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    Marinobacter lipolyticus strain SM19, isolated from saline soil in Spain, is a moderately halophilic bacterium belonging to the class Gammaproteobacteria. Here, we report the draft genome sequence of this strain, which consists of a 4.0-Mb chromosome and which is able to produce the halophilic enzyme lipase LipBL
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