Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 108
Filtrar
1.
Artigo em Inglês | MEDLINE | ID: mdl-38512750

RESUMO

The field of microbial taxonomy is dynamic, aiming to provide a stable and contemporary classification system for prokaryotes. Traditionally, reliance on phenotypic characteristics limited the comprehensive understanding of microbial diversity and evolution. The introduction of molecular techniques, particularly DNA sequencing and genomics, has transformed our perception of prokaryotic diversity. In the past two decades, advancements in genome sequencing have transitioned from traditional methods to a genome-based taxonomic framework, not only to define species, but also higher taxonomic ranks. As technology and databases rapidly expand, maintaining updated standards is crucial. This work seeks to revise the 2018 guidelines for applying genome sequencing data in microbial taxonomy, adapting minimal standards and recommendations to reflect technological progress during this period.


Assuntos
Ácidos Graxos , Análise de Sequência de DNA , Filogenia , Técnicas de Tipagem Bacteriana , RNA Ribossômico 16S/genética , DNA Bacteriano/genética , Composição de Bases , Ácidos Graxos/química
2.
Int J Syst Evol Microbiol ; 73(12)2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38059605

RESUMO

Two novel Micromonospora strains, STR1-7T and STR1S-6T, were isolated from the rhizosphere of a Parastrephia quadrangularis plant growing in the Salar de Tara region of the Atacama Desert, Chile. Chemotaxonomic, cultural and phenotypic features confirmed that the isolates belonged to the genus Micromonospora. They grew from 20 to 37 °C, from pH7 to 8 and in the presence of up to 3 %, w/v NaCl. The isolates formed distinct branches in Micromonospora gene trees based on 16S rRNA gene sequences and on a multi-locus sequence analysis of conserved house-keeping genes. A phylogenomic tree generated from the draft genomes of the isolates and their closest phylogenetic neighbours showed that isolate STR1-7T is most closely related to Micromonospora orduensis S2509T, and isolate STR1S-6 T forms a distinct branch that is most closely related to 12 validly named Micromonospora species, including Micromonospora saelicesensis the earliest proposed member of the group. The isolates were separated from one another and from their closest phylogenomic neighbours using a combination of chemotaxonomic, genomic and phenotypic features, and by low average nucleotide index and digital DNA-DNA hybridization values. Consequently, it is proposed that isolates STR1-7T and STR1S-6T be recognized as representing new species in the genus Micromonospora, namely as Micromonospora parastrephiae sp. nov. and Micromonospora tarensis sp. nov.; the type strains are STR1-7T (=CECT 9665T=LMG 30768T) and STR1S-6T (=CECT 9666T=LMG 30770T), respectively. Genome mining showed that the isolates have the capacity to produce novel specialized metabolites, notably antibiotics and compounds that promote plant growth, as well as a broad-range of stress-related genes that provide an insight into how they cope with harsh abiotic conditions that prevail in high-altitude Atacama Desert soils.


Assuntos
Fabaceae , Micromonospora , Técnicas de Tipagem Bacteriana , Ácidos Graxos/química , Análise de Sequência de DNA , Chile , Filogenia , Rizosfera , RNA Ribossômico 16S/genética , DNA Bacteriano/genética , Composição de Bases
3.
Antonie Van Leeuwenhoek ; 116(11): 1139-1150, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37658955

RESUMO

A non-motile, novel actinobacterial strain, Kera-3T, which is a gram-positive, aerobic, rod-shaped bacterium, was isolated from human keratinocytes on 1/10 diluted R2A agar. Whole-cell hydrolysis of amino acids revealed the presence of meso-DAP, alanine, and glutamic acid. The predominant menaquinone was MK-9 (H8), whereas the primary fatty acids were C16:0 and C18:1 ω9c. The major phospholipids included diphosphatidylglycerol and aminophospholipids, along with an unidentified phosphoglycolipid and an aminophosphoglycolipid. The G+C content of the genomic DNA was 73.2%, based on the complete genome sequence. Phylogenetic analyses of the 16S rRNA gene sequence and phylogenomic analysis of 91 core genes showed that strain Kera-3T formed a new lineage in the family Iamiaceae, with the closest neighbour Rhabdothermincola sediminis SYSU G02662T having 91.19% 16S rRNA gene sequence identity. A comparative genomic study of the predicted general metabolism and carbohydrate-active enzymes supported the phylogenetic and phylogenomic data. Based on the analysis of physiological, biochemical, and genomic characteristics, strain Kera-3T can be distinguished from known genera in the family Iamiaceae and represents a novel genus and species. Therefore, the name Dermatobacter hominis gen. nov., sp. nov. was proposed, with the type strain Kera-3T (= KACC 22415T = LMG 32493T).

4.
J Phys Chem C Nanomater Interfaces ; 127(6): 3059-3066, 2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38333002

RESUMO

Ferrocene and nickelocene do not react with each other in solution; however, the large impact of the paramagnetic component on the ferrocene 1H NMR signal linewidth and relaxation times has been quantified. Co-crystallization of ferrocene and nickelocene at any ratio from a solvent can be explained with both pure substances crystallizing in the same space group P21/n. As a new phenomenon, when a ferrocene single crystal is exposed to polycrystalline nickelocene in the absence of a solvent, the nickelocene migrates into the ferrocene crystal lattice and a mixed crystal is formed that retains its macroscopic shape. This process has been proven visually by cutting the single crystal. Mixing polycrystalline ferrocene with polycrystalline nickelocene at different molar ratios with a mortar and pestle leads to crystalline solid solutions with the corresponding molar ratios of both components. This migration of one organometallic component into an existing crystal lattice of another at ambient temperature in the absence of a solvent has not been described previously. Paramagnetic 1H solid-state NMR spectroscopy of static and rotating samples of dry ferrocene/nickelocene mixtures at varying ratios is used to prove and quantify the mixing of both metallocenes at the molecular level. A single-crystal X-ray structure of a 50/50 mixed crystal corroborates the NMR results that nickelocene and ferrocene are randomly distributed in the lattice and that the space group P21/n is retained. All ferrocene molecules in the mixed crystal lattice show a broadening of their 1H wideline signals and residual magic-angle spinning (MAS) lines at ambient temperature. The broadening of the ferrocene signals correlates with the nickelocene content. 1H T1 relaxation time measurements for the signals of ferrocene in samples with different amounts of nickelocene corroborate the assumption that the signal broadening is due to paramagnetic dipole-dipole relaxation of ferrocene molecules in the vicinity of nickelocene. Spatially separated ferrocene and nickelocene powders in one rotor show the solid-state NMR characteristics of the individual polycrystalline metallocenes. The described formation of solid solutions of metallocenes in the absence of a solvent will open new pathways to homogeneously mixed nanoparticles with desired metal ratios and dual-atom catalysts.

5.
Int J Syst Evol Microbiol ; 72(11)2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36394451

RESUMO

Six actinobacterial strains isolated from diverse legume tissues collected in various locations in Spain were characterized to determine their taxonomic status. Using 16S rRNA gene sequencing, the strains were primarily identified as members of the genus Micromonospora with more than 99 % similarity. Digital DNA-DNA hybridization values and average nucleotide identities between the six strains and the nearest type strains confirmed that each strain represented a novel species. Genome sequences were analysed to infer their metabolic profiles, their potential to produce secondary metabolites and plant growth promoting features. Chemotaxonomic and physiological studies were carried out to complete the phenotypic characterization and to distinguish the new Micromonospora species. The genomic and phenotypic characterization of the Micromonospora strains strongly support their classification as representatives of new species with the following names: Micromonospora alfalfae sp. nov., Micromonospora cabrerizensis sp. nov., Micromonospora foliorum sp. nov., Micromonospora hortensis sp. nov., Micromonospora salmantinae sp. nov. and Micromonospora trifolii sp. nov., with the type strains MED01T, LAH09T, PSH25T, NIE111T, PSH03T and NIE79T, respectively.


Assuntos
Fabaceae , Micromonospora , RNA Ribossômico 16S/genética , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Filogenia , Análise de Sequência de DNA , Composição de Bases , Ácidos Graxos/química , Verduras
6.
Int J Syst Evol Microbiol ; 72(10)2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36256446

RESUMO

The taxonomic status of two Gordonia strains, designated BEN371 and CON9T, isolated from stable foams on activated sludge plants was the subject of a polyphasic study which also included the type strains of Gordonia species and three authenticated Gordonia amarae strains recovered from such foams. Phylogenetic analyses of 16S rRNA gene sequences showed that these isolates formed a compact cluster suggesting a well-supported lineage together with a second branch containing the G. amarae strains. A phylogenomic tree based on sequences of 92 core genes extracted from whole genome sequences of the isolates, the G. amarae strains and Gordonia type strains confirmed the assignment of the isolates and the G. amarae strains to separate but closely associated lineages. Average nucleotide index (ANI) and digital DNA-DNA hybridisation (dDDH) similarities showed that BEN371 and CON9T belonged to the same species and had chemotaxonomic and morphological features consistent with their assignment to the genus Gordonia. The isolates and the G. amarae strains were distinguished using a range of phenotypic features and by low ANI and dDDH values of 84.2 and 27.0 %, respectively. These data supplemented with associated genome characteristics show that BEN371 and CON9T represent a novel species of the genus Gordonia. The name proposed for members of this taxon is Gordonia pseudamarae sp. nov. with isolate CON9T (=DSM 43602T=JCM 35249T) as the type strain.


Assuntos
Actinobacteria , Bactéria Gordonia , Purificação da Água , Esgotos/microbiologia , RNA Ribossômico 16S/genética , Filogenia , DNA Bacteriano/genética , Composição de Bases , Técnicas de Tipagem Bacteriana , Análise de Sequência de DNA , Ácidos Graxos/química , Nucleotídeos
7.
Front Plant Sci ; 13: 872356, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35401599

RESUMO

Understanding plant-microbe interactions with the possibility to modulate the plant's microbiome is essential to design new strategies for a more productive and sustainable agriculture and to maintain natural ecosystems. Therefore, a key question is how to design bacterial consortia that will yield the desired host phenotype. This work was designed to identify the potential genomic features involved in the interaction between Micromonospora and known host plants. Seventy-four Micromonospora genomes representing diverse environments were used to generate a database of all potentially plant-related genes using a novel bioinformatic pipeline that combined screening for microbial-plant related features and comparison with available plant host proteomes. The strains were recovered in three clusters, highly correlated with several environments: plant-associated, soil/rhizosphere, and marine/mangrove. Irrespective of their isolation source, most strains shared genes coding for commonly screened plant growth promotion features, while differences in plant colonization related traits were observed. When Arabidopsis thaliana plants were inoculated with representative Micromonospora strains selected from the three environments, significant differences were in found in the corresponding plant phenotypes. Our results indicate that the identified genomic signatures help select those strains with the highest probability to successfully colonize the plant and contribute to its wellbeing. These results also suggest that plant growth promotion markers alone are not good indicators for the selection of beneficial bacteria to improve crop production and the recovery of ecosystems.

8.
Ther Umsch ; 79(3-4): 133-140, 2022 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-35440187

RESUMO

Achalasia Update Abstract. The neurodegenerative disease achalasia (obsolete: "cardiac spasm") is the second most common functional disease of the esophagus after reflux disease. It is associated with an extremely high level of suffering for the patient. Pathophysiologically, it is a combination of a lack of swallowing-reflex relaxation at the gastric entrance and disturbed peristalsis of the tubular esophagus. The gold standard in diagnostics is high-resolution manometry. The disease cannot be cured, the therapeutic spectrum that alleviates the disease includes pharmaceutical, endoscopic-interventional and surgical procedures.


Assuntos
Acalasia Esofágica , Doenças Neurodegenerativas , Acalasia Esofágica/diagnóstico , Acalasia Esofágica/terapia , Humanos , Manometria , Peristaltismo
9.
Artigo em Inglês | MEDLINE | ID: mdl-35312471

RESUMO

A Gram-stain-positive bacterial strain, designated G127ATT, was isolated as soft small white colonies from the hindgut of the cockroach Archimandrita tesselata. Examination of the complete 16S rRNA sequence mapped the strain to the genus Agromyces. The type strain with the highest pairwise similarity was Agromyces marinus H23-8T (97.3%). The genome of G127ATT was sequenced by a combination of Illumina and Nanopore methods and consisted of a single circular DNA molecule with a size of 3.45 Mb. The DNA G+C content was 71.3 mol%. A phylogenomic tree based on conserved single copy housekeeping genes, placed G127ATT among the ancestral species of the genus Agromyces, and only Agromyces atrinae P27T was found to diverge earlier than G127ATT. Genome distance metrics average nucleotide identity (ANI) (76-78 %) and digital DNA-DNA hybridization (dDDH) (20.2-21.5 %) of the isolate against available genomes of several type strains of species of the genus Agromyces indicated that G127ATT represented a previously undescribed species of the genus Agromyces. Morphological, physiological and biochemical characteristics, including lipid profile, cellular fatty acids and peptidoglycan type were in accordance with usual attributes of members of the genus Agromyces. The novel isolate could be differentiated from the most closely related species by extracellular expression of acid and alkaline phosphatases, trypsin and α-chymotrypsin, and utilization of l-arabinose and salicin as sole carbon sources. On the basis of the combined genomic and phenotypic features, isolate G127ATT (=DSM 111850T=LMG 32099T) is considered to represent a novel species of the genus Agromyces, for which we propose the name Agromyces archimandritae sp. nov.


Assuntos
Baratas , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
10.
Artigo em Inglês | MEDLINE | ID: mdl-35085063

RESUMO

An alkaliphilic actinobacterium, designated VN6-2T, was isolated from marine sediment collected from Valparaíso Bay, Chile. Strain VN6-2T formed yellowish-white branched substrate mycelium without fragmentation. Aerial mycelium was well developed, forming wavy or spiral spore chains. Strain VN6-2T exhibited a 16S rRNA gene sequence similarity of 93.9 % to Salinactinospora qingdaonensis CXB832T, 93.7 % to Murinocardiopsis flavida 14-Be-013T, and 93.7 % to Lipingzhangella halophila 14-Be-013T. Genome sequencing revealed a genome size of 5.9 Mb and an in silico G+C content of 69.3 mol%. Both of the phylogenetic analyses based on 16S rRNA gene sequences and the up-to-date bacterial core gene sequences revealed that strain VN6-2T formed a distinct monophyletic clade within the family Nocardiopsaceae. Chemotaxonomic assessment of strain VN6-2T showed that the major fatty acids were iso-C16 : 0, anteiso-C17 : 0 and 10-methyl-C18 : 0, and the predominant respiratory quinones were MK-9, MK-9(H2) and MK-9(H4). Whole-cell hydrolysates contained meso-diaminopimelic acid as the cell-wall diamino acid, and ribose and xylose as the diagnostic sugars. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, aminophospholipids, glycolipid and phospholipid. Based on the results of this polyphasic study, a novel genus, Spiractinospora gen. nov., is proposed within the family Nocardiopsaceae and the type species Spiractinospora alimapuensis gen. nov., sp. nov. The type strain is VN6-2T (CECT 30026T, CCUG 66258T). On the basis of the phylogenetic results herein, we also propose that Nocardiopsis arvandica and Nocardiopsis litoralis are later heterotypic synonyms of Nocardiopsis sinuspersici and Nocardiopsis kunsanensis, respectively, for which emended descriptions are given.


Assuntos
Sedimentos Geológicos/microbiologia , Nocardiopsis , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , Baías , Chile , DNA Bacteriano/genética , Ácidos Graxos/química , Nocardiopsis/classificação , Nocardiopsis/isolamento & purificação , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/química
11.
Int J Syst Evol Microbiol ; 72(12)2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36748408

RESUMO

The recent publication of an alternative nomenclatural code that targets prokaryotes, the Code of Nomenclature of Prokaryotes Described from DNA Sequence Data (SeqCode), raises questions about how to treat names 'validly published' under that code in the International Journal of Systematic and Evolutionary Microbiology (IJSEM). Here, it is reiterated that the IJSEM must function in accordance with the International Code of Nomenclature of Prokaryotes (ICNP). It is also reiterated that the ICNP covers all prokaryotes and that it accordingly assigns a nomenclatural status to all names of prokaryotic taxa. This implies that the ICNP also assigns a status to names that are only 'validly published' under the SeqCode. It follows that the IJSEM must treat such names as not validly published, since 'validly published under the SeqCode' is not a nomenclatural status, under the ICNP. Such names should be marked accordingly as Candidatus names or printed in quotation marks. The same measures would need to be taken by other journals which intend to adhere to the ICNP.


Assuntos
Ácidos Graxos , Filogenia , DNA Bacteriano/genética , Composição de Bases , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Técnicas de Tipagem Bacteriana , Ácidos Graxos/química
12.
Microb Ecol ; 82(3): 746-760, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33604703

RESUMO

Species may co-occur due to responses to similar environmental conditions, biological associations, or simply because of coincident geographical distributions. Disentangling patterns of co-occurrence and potential biotic and abiotic interactions is crucial to understand ecosystem function. Here, we used DNA metabarcoding data from litter and mineral soils collected from a longitudinal transect in Amazonia to explore patterns of co-occurrence. We compared data from different Amazonian habitat types, each with a characteristic biota and environmental conditions. These included non-flooded rainforests (terra-firme), forests seasonally flooded by fertile white waters (várzeas) or by unfertile black waters (igapós), and open areas associated with white sand soil (campinas). We ran co-occurrence network analyses based on null models and Spearman correlation for all samples and for each habitat separately. We found that one third of all operational taxonomic units (OTUs) were bacteria and two thirds were eukaryotes. The resulting networks were nevertheless mostly composed of bacteria, with fewer fungi, protists, and metazoans. Considering the functional traits of the OTUs, there is a combination of metabolism modes including respiration and fermentation for bacteria, and a high frequency of saprotrophic fungi (those that feed on dead organic matter), indicating a high turnover of organic material. The organic carbon and base saturation indices were important in the co-occurrences in Amazonian networks, whereas several other soil properties were important for the co-exclusion. Different habitats had similar network properties with some variation in terms of modularity, probably associated with flooding pulse. We show that Amazonian microorganism communities form highly interconnected co-occurrence and co-exclusion networks, which highlights the importance of complex biotic and abiotic interactions in explaining the outstanding biodiversity of the region.


Assuntos
Código de Barras de DNA Taxonômico , Ecossistema , Biodiversidade , Florestas , Floresta Úmida , Microbiologia do Solo
13.
Artigo em Inglês | MEDLINE | ID: mdl-33605868

RESUMO

The International Journal of Systematic and Evolutionary Microbiology (IJSEM) will move to 'true continuous publication' during the first months of 2021 to modernize the workflow and align it with the current online-only nature of the journal. In the new format, articles will be cited using an article number rather than page numbering. The article number will be the Digital Object Identifier (DOI) suffix, i.e., the last six digits of the DOI. Benefits of the new system include streamlining in-house processes, hence, reducing time and costs, and speeding up the publication time of the final 'Version of Record'. Because of the new format of the IJSEM, it is necessary to emend Rule 24b (2) and Note 1 paragraph 3 of Rule 27 of the International Code of Nomenclature of Prokaryotes (ICNP) to regulate matters of priority for papers published after January 2021. We also propose adding another example to Note 2 of Rule 33b to clarify how nomenclatural authorities of names published in the IJSEM from 2021 onward must be cited.

14.
Int J Syst Evol Microbiol ; 70(11): 5888-5898, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33034549

RESUMO

Two morphologically similar halophilic strains, named USBA 874 and USBA 960T, were isolated from water and sediment samples collected from the Zipaquirá salt mine in the Colombian Andes. Both isolates had non-spore-forming, Gram-stain-negative and motile cells that grew aerobically. The strains grew optimally at 30 °C, pH 7.0 and with 25 % NaCl (w/v). The isolates showed almost identical 16S rRNA gene sequences (99.0 % similarity). The predominant quinones of USBA-960T were Q-8, Q-7 and Q-9. The major cellular fatty acids were C19 : 0 cyclo ω8c, C18 : 0 and C16 : 0. According to 16S rRNA gene sequencing, the closest phylogenetic relatives are Salinisphaera species (similarity between 93.6 and 92.3 %), Abyssibacter profundi OUC007T (88.6 %) and Oceanococcus atlanticus 22II-S10r2T (88.7 %). In addition, the result of genome blast distance phylogeny analysis between strains USBA 874 and USBA 960T, Salinisphaera halophila (YIM 95161T), Salinisphaera shabanensis (E1L3AT), Salinisphaera orenii (MK-B5T) and Salinisphaera japonica (YTM-1T) was 18.5 %. Other in silico species delineation analyses also showed low identity such as ANIb and ANIm values (<69.0 and <84.0 % respectively), TETRA (<0.81) and AAI values (<0.67). Genome sequencing of USBA 960T revealed a genome size of 2.47 Mbp and a G+C content of 59.71 mol%. Phylogenetic analysis of strains USBA 874 and USBA 960T indicated that they formed a different lineage within the family Salinisphaeraceae. Based on phenotypic and chemotaxonomic characteristics, phylogenetic analysis and DNA-DNA relatedness values, along with identity at whole genome level, it can be concluded that strains USBA 960T and USBA 874 represent a novel genus of the family Salinisphaeraceae and the name Salifodinibacter halophilus gen. nov., sp. nov. is proposed. The type strain is USBA 960T (CMPUJ U095T=CECT 30006T).


Assuntos
Gammaproteobacteria/classificação , Mineração , Filogenia , Cloreto de Sódio , Técnicas de Tipagem Bacteriana , Composição de Bases , Colômbia , DNA Bacteriano/genética , Ácidos Graxos/química , Gammaproteobacteria/isolamento & purificação , Tamanho do Genoma , Sedimentos Geológicos/microbiologia , Quinonas/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Microbiologia da Água
15.
Int J Syst Evol Microbiol ; 70(8): 4668-4682, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32701422

RESUMO

Ten representative actinobacterial strains isolated from marine sediments collected worldwide were studied to determine their taxonomic status. The strains were previously identified as members of the genus Salinispora and shared >99 % 16S rRNA gene sequence similarity to the three currently recognized Salinispora species. Comparative genomic analyses resulted in the delineation of six new species based on average nucleotide identity and digital DNA-DNA hybridization values below 95 and 70 %, respectively. The species status of the six new groups was supported by a core-genome phylogeny reconstructed from 2106 orthologs detected in 118 publicly available Salinispora genomes. Chemotaxonomic and physiological studies were used to complete the phenotypic characterization of the strains. The fatty acid profiles contained the major components iso-C16 : 0, C15 : 0, iso-17 : 0 and anteiso C17 : 0. Galactose and xylose were common in all whole-sugar patterns but differences were found between the six groups of strains. Polar lipid compositions were also unique for each species. Distinguishable physiological and biochemical characteristics were also recorded. The names proposed are Salinispora cortesiana sp. nov., CNY-202T (=DSM 108615T=CECT 9739T); Salinispora fenicalii sp. nov., CNT-569T (=DSM 108614T=CECT 9740T); Salinispora goodfellowii sp. nov., CNY-666T (=DSM 108616T=CECT 9738T); Salinispora mooreana sp. nov., CNT-150T (=DSM 45549T=CECT 9741T); Salinispora oceanensis sp. nov., CNT-138T (=DSM 45547T=CECT 9742T); and Salinispora vitiensis sp. nov., CNT-148T (=DSM 45548T=CECT 9743T).


Assuntos
Sedimentos Geológicos/microbiologia , Micromonosporaceae/classificação , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
16.
Int J Syst Evol Microbiol ; 70(7): 3956-4042, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32603289

RESUMO

We here present annotated lists of names of Candidatus taxa of prokaryotes with ranks between subspecies and class, proposed between the mid-1990s, when the provisional status of Candidatus taxa was first established, and the end of 2018. Where necessary, corrected names are proposed that comply with the current provisions of the International Code of Nomenclature of Prokaryotes and its Orthography appendix. These lists, as well as updated lists of newly published names of Candidatus taxa with additions and corrections to the current lists to be published periodically in the International Journal of Systematic and Evolutionary Microbiology, may serve as the basis for the valid publication of the Candidatus names if and when the current proposals to expand the type material for naming of prokaryotes to also include gene sequences of yet-uncultivated taxa is accepted by the International Committee on Systematics of Prokaryotes.


Assuntos
Bactérias/classificação , Terminologia como Assunto
17.
Sci Total Environ ; 739: 139850, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32554115

RESUMO

Heavy metal pollution in the environment is an increasing problem due to natural and anthropogenic activities. The use of bacteria for bioremediation of soils contaminated with heavy metals has gained a lot of attention as it can be considered effective, economic and environmentally sustainable. In this work, we investigated the capacity of endophytic Micromonospora strains isolated from different legumes, to produce metallophores against a variety of heavy metals in vitro. Genome mining using available endophytic Micromonospora genome sequences revealed the presence of genes related to metal acquisition, iron metabolism and resistance to toxic compounds. In vitro production of metallophores demonstrated that all strains tested produced chelates against arsenic, cobalt, copper, chromium, iron, mercury, molybdenum, nickel, vanadium and zinc in different amounts. In addition, the plant growth promotion effect of strains GAR05 and PSN13 on Arabidopsis thaliana grown in the presence of several heavy metals was tested. Under these conditions, the plants inoculated with the strain GAR05 showed significant growth when compared to the control plants suggesting a plant growth promotion effect in the form of tolerance to the toxic substances. Furthermore, during this plant-bacterium interaction, a new bacterial structure named root-bead was observed on the roots of A. thaliana suggesting a strong interaction between the two organisms and a clear positive effect of the bacterium on the plant. Overall, these results highlight the potential use of endophytic Micromonospora strains for bacterial-assisted phytoremediation of contaminated sites.


Assuntos
Metais Pesados/análise , Micromonospora , Poluentes do Solo/análise , Bactérias , Biodegradação Ambiental , Raízes de Plantas/química
18.
Int J Neurosci ; 130(4): 398-406, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31714811

RESUMO

Background: Neurosciences research has increased significantly in recent years around the world. It has led to the development of interdisciplinary work, moving from activities from isolated fields (such as biology, psychology or neurology) to research that involves different scientific perspectives. In developing regions, such as Latin America, it has additional challenges, related to available funding and infrastructure.Aim: To analyze key factors in scientific productivity in neurosciences in Latin America.Methods: A bibliometric analysis of the scientific productivity in neurosciences in main five Latin American countries (Argentina, Brazil, Chile, Colombia and Mexico) was carried out.Results: Brazil was the largest producer of scientific articles, and receptor of citations, in neurosciences in 1998-2017, followed by Mexico. We identified highly cited papers, top institutions, networks of authors, main journals and key areas in neurosciences for this period in the 5 countries.Conclusions: Scientific productivity in neurosciences in Latin America would benefit from the consolidation of more regional, interdisciplinary and international research networks. In this work, we discuss key elements for the consolidation of neurosciences research in Latin America.


Assuntos
Bibliometria , Neurociências/estatística & dados numéricos , Publicações Periódicas como Assunto/estatística & dados numéricos , Pesquisa Biomédica/estatística & dados numéricos , Humanos , América Latina , Revisão da Pesquisa por Pares
20.
Syst Appl Microbiol ; 43(1): 126043, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31796230

RESUMO

The genus Micromonospora has been found in nodules of several legumes and some new species of this genus were isolated from these plant organs. In this study we analysed the taxonomic diversity of Micromonospora strains isolated from alfalfa nodules in Spain and Australia on the basis of three phylogenetic markers, the rrs and gyrB genes and 16S-23S intergenic spacer (ITS). The genome analysis of selected strains representative of different clusters or lineages found after rrs, gyrB and ITS analyses confirmed the results obtained with these phylogenetic markers. They showed that the analysed strains belong to at least 18 Micromonospora species including previously described ones, such as Micromonospora noduli, Micromonospora ureilytica, Micromonospora taraxaci, Micromonospora zamorensis, Micromonospora aurantiaca and Micromonospora tulbaghiae. Most of these strains belong to undescribed species of Micromonospora showing the high taxonomic diversity of strains from this genus inhabiting alfalfa nodules. Although Micromonospora strains are not able to induce the formation of these nodules, and it seems that they do not contribute to fix atmospheric nitrogen, they could play a role related with the mechanisms of plant growth promotion and pathogen protection presented by Micromonospora strains isolated from legume nodules.


Assuntos
Biodiversidade , Medicago sativa , Micromonospora/classificação , Nódulos Radiculares de Plantas/microbiologia , Austrália , DNA Bacteriano/genética , DNA Espaçador Ribossômico/genética , Genes Bacterianos/genética , Genes Essenciais/genética , Micromonospora/genética , Micromonospora/isolamento & purificação , Hibridização de Ácido Nucleico , Filogenia , Análise de Sequência de DNA , Espanha
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...