scholarly journals Phylogenetic analysis based evolutionary study of 16S rRNA in known Pseudomonas sp

2015 ◽  
Vol 11 (10) ◽  
pp. 474-480 ◽  
Author(s):  
Arindam Adhikari ◽  
◽  
Suvodip Nandi ◽  
Indrabrata Bhattacharya ◽  
Mithu De Roy ◽  
...  
Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 15
Author(s):  
Badreddine Sijilmassi ◽  
Abdelkarim Filali-Maltouf ◽  
Hassan Boulahyaoui ◽  
Aymane Kricha ◽  
Kenza Boubekri ◽  
...  

A total of 14 Rhizobium strains were isolated from lentil accessions grown at the ICARDA experimental research station at Marchouch in Morocco and used for molecular characterization and symbiotic efficiency assessment. Individual phylogenetic analysis using the 16S rRNA gene, house-keeping genes rpoB, recA, and gyrB, and symbiotic genes nodD and nodA along with Multilocus Sequence Analysis (MLSA) of the concatenated genes (16S rRNA-rpoB-recA-gyrB) was carried out for the identification and clustering of the isolates. The symbiotic efficiency of the strains was assessed on three Moroccan lentil cultivars (Bakria, Chakkouf, and Zaria) based on the number of nodules, plant height, plant dry weight, and total nitrogen content in leaves. The results showed that the individual phylogenetic analysis clustered all the strains into Rhizobium laguerreae and Rhizobium leguminosarum with sequence similarity ranging from 94 to 100%, except one strain which clustered with Mesorhizobium huakuii with sequence similarity of 100%. The MLSA of the concatenated genes and the related percentages of similarity clustered these strains into two groups of Rhizobium species, with one strain as a new genospecies when applying the threshold of 96%. For symbiotic efficiency, the Bakria variety showed the best association with 10 strains compared to its non-inoculated control (p-value ≤ 0.05), followed by Chakkouf and Zaria. The present study concluded that the genetic diversity and the symbiotic efficiency of Rhizobium strains appeared to be mainly under the control of the lentil genotypes.


2007 ◽  
Vol 73 (20) ◽  
pp. 6682-6685 ◽  
Author(s):  
Daniel P. R. Herlemann ◽  
Oliver Geissinger ◽  
Andreas Brune

ABSTRACT The bacterial candidate phylum Termite Group I (TG-1) presently consists mostly of “Endomicrobia,” which are endosymbionts of flagellate protists occurring exclusively in the hindguts of termites and wood-feeding cockroaches. Here, we show that public databases contain many, mostly undocumented 16S rRNA gene sequences from other habitats that are affiliated with the TG-1 phylum but are only distantly related to “Endomicrobia.” Phylogenetic analysis of the expanded data set revealed several diverse and deeply branching lineages comprising clones from many different habitats. In addition, we designed specific primers to explore the diversity and environmental distribution of bacteria in the TG-1 phylum.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hongru Su ◽  
Eri Onoda ◽  
Hitoshi Tai ◽  
Hiromi Fujita ◽  
Shigetoshi Sakabe ◽  
...  

AbstractEhrlichia species are obligatory intracellular bacteria transmitted by arthropods, and some of these species cause febrile diseases in humans and livestock. Genome sequencing has only been performed with cultured Ehrlichia species, and the taxonomic status of such ehrlichiae has been estimated by core genome-based phylogenetic analysis. However, many uncultured ehrlichiae exist in nature throughout the world, including Japan. This study aimed to conduct a molecular-based taxonomic and ecological characterization of uncultured Ehrlichia species or genotypes from ticks in Japan. We first surveyed 616 Haemaphysalis ticks by p28-PCR screening and analyzed five additional housekeeping genes (16S rRNA, groEL, gltA, ftsZ, and rpoB) from 11 p28-PCR-positive ticks. Phylogenetic analyses of the respective genes showed similar trees but with some differences. Furthermore, we found that V1 in the V1–V9 regions of Ehrlichia 16S rRNA exhibited the greatest variability. From an ecological viewpoint, the amounts of ehrlichiae in a single tick were found to equal approx. 6.3E+3 to 2.0E+6. Subsequently, core-partial-RGGFR-based phylogenetic analysis based on the concatenated sequences of the five housekeeping loci revealed six Ehrlichia genotypes, which included potentially new Ehrlichia species. Thus, our approach contributes to the taxonomic profiling and ecological quantitative analysis of uncultured or unidentified Ehrlichia species or genotypes worldwide.


2006 ◽  
Vol 56 (7) ◽  
pp. 1547-1552 ◽  
Author(s):  
Michael Fahrbach ◽  
Jan Kuever ◽  
Ruth Meinke ◽  
Peter Kämpfer ◽  
Juliane Hollender

A Gram-negative, motile, denitrifying bacterium (strain AcBE2-1T) was isolated from activated sludge of a municipal wastewater treatment plant using 17β-oestradiol (E2) as sole source of carbon and energy. Cells were curved rods, 0.4–0.8×0.8–2.0 μm in size, non-fermentative, non-spore-forming, oxidase-positive and catalase-negative. E2 was oxidized completely to carbon dioxide and water by reduction of nitrate to a mixture of dinitrogen monoxide and dinitrogen, with the intermediate accumulation of nitrite. Electron recoveries were between 90 and 100 %, taking assimilated E2 into account. With nitrate as the electron acceptor, the bacterium also grew on fatty acids (C2 to C6), isobutyrate, crotonate, dl-lactate, pyruvate, fumarate and succinate. Phylogenetic analysis of its 16S rRNA gene sequence revealed that strain AcBE2-1T represents a separate line of descent within the family Rhodocyclaceae (Betaproteobacteria). The closest relatives are the cholesterol-degrading, denitrifying bacteria Sterolibacterium denitrificans DSM 13999T and strain 72Chol (=DSM 12783), with <93.9 % sequence similarity. The G+C content of the DNA was 61.4 mol%. Detection of a quinone system with ubiquinone Q-8 as the predominant compound and a fatty acid profile that included high concentrations of C16 : 1 ω7c/iso-C15 : 0 2-OH and C16 : 0, in addition to C18 : 1 ω7c and small amounts of C8 : 0 3-OH, supported the results of the phylogenetic analysis. On the basis of 16S rRNA gene sequence data in combination with chemotaxonomic and physiological data, strain AcBE2-1T (=DSM 16959T=JCM 12830T) is placed in a new genus Denitratisoma gen. nov. as the type strain of the type species Denitratisoma oestradiolicum gen. nov., sp. nov.


2006 ◽  
Vol 56 (9) ◽  
pp. 2147-2152 ◽  
Author(s):  
Om Prakash ◽  
Rup Lal

A phenanthrene-degrading bacterium, strain TKPT, was isolated from a fly ash dumping site of the thermal power plant in Panki, Kanpur, India, by an enrichment culture method using phenanthrene as the sole source of carbon and energy. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain belonged to the genus Sphingobium, as it showed highest sequence similarity to Sphingobium herbicidovorans DSM 11019T (97.3 %) and Sphingomonas cloacae JCM 10874T (96.5 %), compared with only 91–93 % similarity to members of other genera such as Sphingomonas sensu stricto, Novosphingobium, Sphingopyxis and Sphingosinicella. In DNA–DNA hybridization experiments with strains that were closely related phylogenetically and in terms of 16S rRNA gene sequences, i.e. Sphingobium herbicidovorans DSM 11019T and Sphingomonas cloacae JCM 10874T, strain TKPT showed less than 70 % relatedness. Strain TKPT contained sphingoglycolipids SGL-1 and SGL-2 and 18 : 1ω7c as the predominant fatty acid, with 16 : 0 as a minor component and 14 : 0 2-OH as the major 2-hydroxy fatty acid. Thus, phylogenetic analysis, DNA–DNA hybridization, fatty acid and polar lipid profiles and differences in physiological and morphological features from the most closely related members of the Sphingobium group showed that strain TKPT represents a distinct species of Sphingobium. The name Sphingobium fuliginis sp. nov. is proposed, with the type strain TKPT (=MTCC 7295T=CCM 7327T). Sphingomonas cloacae JCM 10874T formed a coherent cluster with members of Sphingobium, did not reduce nitrate to nitrite and had a fatty acid profile similar to those of Sphingobium species; hence Sphingomonas cloacae should be transferred to the genus Sphingobium as Sphingobium cloacae comb. nov., with the type strain JCM 10874T (=DSM 14926T).


2011 ◽  
Vol 61 (12) ◽  
pp. 2974-2978 ◽  
Author(s):  
Jinxing Zhu ◽  
Xiaoli Liu ◽  
Xiuzhu Dong

Two mesophilic methanogenic strains, designated TS-2T and GHT, were isolated from sediments of Tuosu lake and Gahai lake, respectively, in the Qaidam basin, Qinghai province, China. Cells of both isolates were rods (about 0.3–0.5×2–5 µm) with blunt rounded ends and Gram-staining-positive. Strain TS-2T was motile with one or two polar flagella and used only H2/CO2 for growth and methanogenesis. Strain GHT was non-motile, used both H2/CO2 and formate and displayed a variable cell arrangement depending on the substrate: long chains when growing in formate (50 mM) or under high pressure H2 and single cells under low pressure H2. Phylogenetic analysis based on 16S rRNA gene sequences placed the two isolates in the genus Methanobacterium. Strain TS-2T was most closely related to Methanobacterium alcaliphilum NBRC 105226T (96 % 16S rRNA gene sequence similarity). Phylogenetic analysis based on the alpha subunit of methyl-coenzyme M reductase also supported the affiliation of the two isolates with the genus Methanobacterium. DNA–DNA relatedness between the isolates and M. alcaliphilum DSM 3387T was 39–53 %. Hence we propose two novel species, Methanobacterium movens sp. nov. (type strain TS-2T = AS 1.5093T = JCM 15415T) and Methanobacterium flexile sp. nov. (type strain GHT = AS 1.5092T = JCM 15416T).


2018 ◽  
Author(s):  
Mingwei Cai ◽  
Yang Liu ◽  
Zhichao Zhou ◽  
Yuchun Yang ◽  
Jie Pan ◽  
...  

AbstractAsgard is a newly proposed archaeal superphylum. Phylogenetic position of Asgard archaea and its relationships to the origin of eukaryotes is attracting increasingly research interest. However, in-depth knowledge of their diversity, distribution, and activity of Asgard archaea remains limited. Here, we used phylogenetic analysis to cluster the publicly available Asgard archaeal 16S rRNA gene sequences into 13 subgroups, including five previously unknown subgroups. These lineages were widely distributed in anaerobic environments, with the majority of 16S rRNA gene sequences (92%) originating from sediment habitats. Co-occurrence analysis revealed potential relationships between Asgard, Bathyarchaeota, and Marine Benthic Group D archaea. Genomic analysis suggested that Asgard archaea are potentially mixotrophic microbes with divergent metabolic capabilities. Importantly, metatranscriptomics confirmed the versatile lifestyles of Lokiarchaeota and Thorarchaeota, which can fix CO2using the tetrahydromethanopterin Wood-Ljungdahl pathway, perform acetogenesis, and degrade organic matters. Overall, this study broadens the understandings of Asgard archaea ecology, and also provides the first evidence to support a transcriptionally active mixotrophic lifestyle of Asgard archaea, shedding light on the potential roles of these microorganisms in the global biogeochemical cycling.


2010 ◽  
Vol 76 (13) ◽  
pp. 4587-4591 ◽  
Author(s):  
C. Talbi ◽  
M. J. Delgado ◽  
L. Girard ◽  
A. Ramírez-Trujillo ◽  
J. Caballero-Mellado ◽  
...  

ABSTRACT Phylogenetic analysis of 16S rRNA, nodC, and nifH genes of four bacterial strains isolated from root nodules of Phaseolus vulgaris grown in Morocco soils were identified as Burkholderia phymatum. All four strains formed N2-fixing nodules on P. vulgaris and Mimosa, Acacia, and Prosopis species and reduced acetylene to ethylene when cultured ex planta.


2015 ◽  
Vol 65 (Pt_2) ◽  
pp. 723-731 ◽  
Author(s):  
Ronel Roberts ◽  
Emma T. Steenkamp ◽  
Gerhard Pietersen

Greening disease of citrus in South Africa is associated with ‘Candidatus Liberibacter africanus’ (Laf), a phloem-limited bacterium vectored by the sap-sucking insect Trioza erytreae (Triozidae). Despite the implementation of control strategies, this disease remains problematic, suggesting the existence of reservoir hosts to Laf. The current study aimed to identify such hosts. Samples from 234 trees of Clausena anisata, 289 trees of Vepris lanceolata and 231 trees of Zanthoxylum capense were collected throughout the natural distribution of these trees in South Africa. Total DNA was extracted from samples and tested for the presence of liberibacters by a generic Liberibacter TaqMan real-time PCR assay. Liberibacters present in positive samples were characterized by amplifying and sequencing rplJ, omp and 16S rRNA gene regions. The identity of tree host species from which liberibacter sequences were obtained was verified by sequencing host rbcL genes. Of the trees tested, 33 specimens of Clausena, 17 specimens of Vepris and 10 specimens of Zanthoxylum tested positive for liberibacter. None of the samples contained typical citrus-infecting Laf sequences. Phylogenetic analysis of 16S rRNA gene sequences indicated that the liberibacters obtained from Vepris and Clausena had 16S rRNA gene sequences identical to that of ‘Candidatus Liberibacter africanus subsp. capensis’ (LafC), whereas those from Zanthoxylum species grouped separately. Phylogenetic analysis of the rplJ and omp gene regions revealed unique clusters for liberibacters associated with each tree species. We propose the following names for these novel liberibacters: ‘Candidatus Liberibacter africanus subsp. clausenae’ (LafCl), ‘Candidatus Liberibacter africanus subsp. vepridis’ (LafV) and ‘Candidatus Liberibacter africanus subsp. zanthoxyli’ (LafZ). This study did not find any natural hosts of Laf associated with greening of citrus. While native citrus relatives were shown to be infected with Laf-related liberibacters, nucleotide sequence data suggest that these are not alternative sources of Laf to citrus orchards, per se.


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