scholarly journals Phylogenetic analyses of some extremely halophilic archaea isolated from Dead Sea water, determined on the basis of their 16S rRNA sequences.

1996 ◽  
Vol 62 (10) ◽  
pp. 3779-3786 ◽  
Author(s):  
D R Arahal ◽  
F E Dewhirst ◽  
B J Paster ◽  
B E Volcani ◽  
A Ventosa
Keyword(s):  
16S Rrna ◽  
Sea Water ◽  
Phylogenetic Analyses ◽  
Halophilic Archaea ◽  
Dead Sea ◽  
Extremely Halophilic Archaea ◽  
Rrna Sequences ◽  
16S Rrna Sequences

Ewamiania thermalis gen. et sp. nov. (Cyanobacteria, Scytonemataceae), a new cyanobacterium from Talaroo thermal springs, north-eastern Australia

2017 ◽  
Vol 30 (1) ◽  
pp. 38 ◽  
Author(s):  
Glenn B. McGregor ◽  
Barbara C. Sendall
Keyword(s):  
16S Rrna ◽  
Phylogenetic Analyses ◽  
Thermal Spring ◽  
Thermal Waters ◽  
Monophyletic Clade ◽  
Vegetative Cells ◽  
Eastern Australia ◽  
North Eastern ◽  
Rrna Sequences ◽  
16S Rrna Sequences

A new subaerophytic cyanobacterium, Ewamiania thermalis gen. et sp. nov., was isolated from a thermal spring complex in tropical, north-eastern Australia and characterised using combined morphological and phylogenetic attributes. It formed blackish-green hemispherical caespitose mats that began as small circular tufts, maturing to form dense mats up to several metres long. It grew along the crests of the minidams just above the thermal waters as well as along some of the shallow unconfined areas of vent-discharge aprons. Morphologically, Ewamiania is most similar to members of the Scytonemataceae. Filaments were isopolar, cylindrical, straight or flexuous, densely arranged and erect, often parallely fasciculate, with tolypotrichoid false-branching, rarely with scytonematoid false-branching. Vegetative cells were short barrel-shaped or isodiametric, slightly constricted at the cross-walls, with granulated contents. Sheaths were firm, thick, lamellated, uncoloured to yellowish or darkly yellow–brown in colour, cylindrical and closed at the apex. Heterocytes were spherical or ovoid in shape, and occurred in both basal and intercalary positions, generally solitary, but sometimes up to two or three in a series, developing particularly at the base of branches. Reproduction occurred by the production of hormogonia by the formation of necridic cells; hormogonia were not constricted at cross-walls and often included terminal heterocytes. Phylogenetic analyses using partial 16S rRNA sequences obtained from a strain of E. thermalis showed that it formed a well supported monophyletic clade, sharing less than 94.3% nucleotide similarity with other cyanobacterial sequences, including putatively related taxa within the Scytonemataceae. It also formed a novel clade in the nifH phylogeny, which was associated with members of the genus Brasilonema M.F.Fiore, Sant’Anna, M.T.P.Azevedo, Komárek, Kastovsky, Sulek & Lorenzi.

scholarly journals Evolutionary Relationships among Primary Endosymbionts of the Mealybug Subfamily Phenacoccinae (Hemiptera: Coccoidea: Pseudococcidae)

2010 ◽  
Vol 76 (22) ◽  
pp. 7521-7525 ◽  
Author(s):  
Matthew E. Gruwell ◽  
Nate B. Hardy ◽  
Penny J. Gullan ◽  
Katharina Dittmar
Keyword(s):  
16S Rrna ◽  
Nucleotide Substitution ◽  
Phylogenetic Analyses ◽  
Sister Group ◽  
Buchnera Aphidicola ◽  
Free Living ◽  
Bacterial Endosymbionts ◽  
Rrna Sequences ◽  
Living Bacteria ◽  
16S Rrna Sequences

ABSTRACT Mealybugs (Coccoidea: Pseudococcidae) are sap-sucking plant parasites that harbor bacterial endosymbionts within specialized organs. Previous studies have identified two subfamilies, Pseudococcinae and Phenacoccinae, within mealybugs and determined the primary endosymbionts (P-endosymbionts) of the Pseudococcinae to be Betaproteobacteria (“Candidatus Tremblaya princeps”) containing Gammaproteobacteria secondary symbionts. Here, the P-endosymbionts of phenacoccine mealybugs are characterized based on 16S rRNA from the bacteria of 20 species of phenacoccine mealybugs and four outgroup Puto species (Coccoidea: Putoidae) and aligned to more than 100 published 16S rRNA sequences from symbiotic and free-living bacteria. Phylogenetic analyses recovered three separate lineages of bacteria from the Phenacoccinae, and these are considered to be the P-endosymbionts of their respective mealybug hosts, with those from (i) the mealybug genus Rastrococcus belonging to the Bacteroidetes, (ii) the subterranean mealybugs, tribe Rhizoecini, also within Bacteroidetes, in a clade sister to cockroach endosymbionts (Blattabacterium), and (iii) the remaining Phenacoccinae within the Betaproteobacteria, forming a well-supported sister group to “Candidatus Tremblaya princeps.” Names are proposed for two strongly supported lineages: “Candidatus Brownia rhizoecola” for P-endosymbionts of Rhizoecini and “Candidatus Tremblaya phenacola” for P-endosymbionts of Phenacoccinae excluding Rastrococcus and Rhizoecini. Rates of nucleotide substitution among lineages of Tremblaya were inferred to be significantly faster than those of free-living Betaproteobacteria. Analyses also recovered a clade of Gammaproteobacteria, sister to the P-endosymbiont lineage of aphids (“Candidatus Buchnera aphidicola”), containing the endosymbionts of Putoidae, the secondary endosymbionts of pseudococcine mealybugs, and the endosymbionts of several other insect groups.

scholarly journals 16S rRNA Phylogeny of Sponge-Associated Cyanobacteria

2005 ◽  
Vol 71 (7) ◽  
pp. 4127-4131 ◽  
Author(s):  
Laura Steindler ◽  
Dorothée Huchon ◽  
Adi Avni ◽  
Micha Ilan
Keyword(s):  
16S Rrna ◽  
Phylogenetic Analyses ◽  
16S Rrna Phylogeny ◽  
Rrna Phylogeny ◽  
Rrna Sequences ◽  
16S Rrna Sequences

ABSTRACT Phylogenetic analyses of 16S rRNA sequences of sponge-associated cyanobacteria showed them to be polyphyletic, implying that they derived from multiple independent symbiotic events. Most of the symbiont sequences were affiliated to a group of Synechococcus and Prochlorococcus species. However, other symbionts were related to different groups, such as the Oscillatoriales.

scholarly journals Phylogeny of All Recognized Species of Ammonia Oxidizers Based on Comparative 16S rRNA and amoA Sequence Analysis: Implications for Molecular Diversity Surveys

2000 ◽  
Vol 66 (12) ◽  
pp. 5368-5382 ◽  
Author(s):  
Ulrike Purkhold ◽  
Andreas Pommerening-R�ser ◽  
Stefan Juretschko ◽  
Markus C. Schmid ◽  
Hans-Peter Koops ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
16S Rrna ◽  
Molecular Diversity ◽  
Sequence Data ◽  
Sequence Similarity ◽  
Phylogenetic Analyses ◽  
Evolutionary Relationships ◽  
Ammonia Oxidizing Bacteria ◽  
Rrna Sequences ◽  
16S Rrna Sequences

ABSTRACT The current perception of evolutionary relationships and the natural diversity of ammonia-oxidizing bacteria (AOB) is mainly based on comparative sequence analyses of their genes encoding the 16S rRNA and the active site polypeptide of the ammonia monooxygenase (AmoA). However, only partial 16S rRNA sequences are available for many AOB species and most AOB have not yet been analyzed on the amoAlevel. In this study, the 16S rDNA sequence data of 10Nitrosomonas species and Nitrosococcus mobiliswere completed. Furthermore, previously unavailable 16S rRNA sequences were determined for three Nitrosomonas sp. isolates and for the gamma-subclass proteobacterium Nitrosococcus halophilus. These data were used to revaluate the specificities of published oligonucleotide primers and probes for AOB. In addition, partial amoA sequences of 17 AOB, including the above-mentioned 15 AOB, were obtained. Comparative phylogenetic analyses suggested similar but not identical evolutionary relationships of AOB by using 16S rRNA and AmoA as marker molecules, respectively. The presented 16S rRNA and amoA and AmoA sequence data from all recognized AOB species significantly extend the currently used molecular classification schemes for AOB and now provide a more robust phylogenetic framework for molecular diversity inventories of AOB. For 16S rRNA-independent evaluation of AOB species-level diversity in environmental samples, amoA and AmoA sequence similarity threshold values were determined which can be used to tentatively identify novel species based on cloned amoA sequences. Subsequently, 122 amoA sequences were obtained from 11 nitrifying wastewater treatment plants. Phylogenetic analyses of the molecular isolates showed that in all but two plants only nitrosomonads could be detected. Although several of the obtained amoAsequences were only relatively distantly related to known AOB, none of these sequences unequivocally suggested the existence of previously unrecognized species in the wastewater treatment environments examined.

scholarly journals Correction to: Bacterial community assemblages in classroom floor dust of 50 public schools in a large city: characterization using 16S rRNA sequences and associations with environmental factors

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Ju-Hyeong Park ◽  
Angela R. Lemons ◽  
Jerry Roseman ◽  
Brett J. Green ◽  
Jean M. Cox-Ganser
Keyword(s):  
Public Schools ◽  
Environmental Factors ◽  
Bacterial Community ◽  
16S Rrna ◽  
Large City ◽  
Floor Dust ◽  
Community Assemblages ◽  
Rrna Sequences ◽  
16S Rrna Sequences

An amendment to this paper has been published and can be accessed via the original article.

scholarly journals 16S rRNA sequences reveal uncultured inhabitants of a well-studied thermal community

1990 ◽  
Vol 75 (2-3) ◽  
pp. 105-115 ◽  
Author(s):  
David M. Ward ◽  
Roland Weller ◽  
Mary M. Bateson
Keyword(s):  
16S Rrna ◽  
Rrna Sequences ◽  
16S Rrna Sequences

scholarly journals Divergence and Redundancy of 16S rRNA Sequences in Genomes with Multiple rrn Operons

2004 ◽  
Vol 186 (9) ◽  
pp. 2629-2635 ◽  
Author(s):  
Silvia G. Acinas ◽  
Luisa A. Marcelino ◽  
Vanja Klepac-Ceraj ◽  
Martin F. Polz
Keyword(s):  
16S Rrna ◽  
Thermophilic Bacteria ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Bacterial Genomes ◽  
16S Rrna Sequence ◽  
Thermoanaerobacter Tengcongensis ◽  
Copy Numbers ◽  
Rrna Sequences ◽  
16S Rrna Sequences

ABSTRACT The level of sequence heterogeneity among rrn operons within genomes determines the accuracy of diversity estimation by 16S rRNA-based methods. Furthermore, the occurrence of widespread horizontal gene transfer (HGT) between distantly related rrn operons casts doubt on reconstructions of phylogenetic relationships. For this study, patterns of distribution of rrn copy numbers, interoperonic divergence, and redundancy of 16S rRNA sequences were evaluated. Bacterial genomes display up to 15 operons and operon numbers up to 7 are commonly found, but ∼40% of the organisms analyzed have either one or two operons. Among the Archaea, a single operon appears to dominate and the highest number of operons is five. About 40% of sequences among 380 operons in 76 bacterial genomes with multiple operons were identical to at least one other 16S rRNA sequence in the same genome, and in 38% of the genomes all 16S rRNAs were invariant. For Archaea, the number of identical operons was only 25%, but only five genomes with 21 operons are currently available. These considerations suggest an upper bound of roughly threefold overestimation of bacterial diversity resulting from cloning and sequencing of 16S rRNA genes from the environment; however, the inclusion of genomes with a single rrn operon may lower this correction factor to ∼2.5. Divergence among operons appears to be small overall for both Bacteria and Archaea, with the vast majority of 16S rRNA sequences showing <1% nucleotide differences. Only five genomes with operons with a higher level of nucleotide divergence were detected, and Thermoanaerobacter tengcongensis exhibited the highest level of divergence (11.6%) noted to date. Overall, four of the five extreme cases of operon differences occurred among thermophilic bacteria, suggesting a much higher incidence of HGT in these bacteria than in other groups.

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