scholarly journals Variation in secondary structure of the 16S rRNA molecule in cyanobacteria with implications for phylogenetic analysis.

Fottea ◽  
2014 ◽  
Vol 14 (2) ◽  
pp. 161-178 ◽  
Author(s):  
Klara Rehakova ◽  
Jeffrey R. Johansen ◽  
Mary B. Bowen ◽  
Michael P. Martin ◽  
Christopher A. Sheil
Keyword(s):  
Phylogenetic Analysis ◽  
Secondary Structure ◽  
16S Rrna ◽  
Rrna Molecule

Phylogenetic analysis of several Thermus strains from Rehai of Tengchong, Yunnan, China

2005 ◽  
Vol 51 (10) ◽  
pp. 881-886 ◽  
Author(s):  
Lianbing Lin ◽  
Jie Zhang ◽  
Yunlin Wei ◽  
Chaoyin Chen ◽  
Qian Peng
Keyword(s):  
Phylogenetic Analysis ◽  
Secondary Structure ◽  
16S Rrna ◽  
Hot Springs ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Structure Comparison ◽  
Rdna Sequences ◽  
16S Rdna Sequences ◽  
Rehai Geothermal Area

Several Thermus strains were isolated from 10 hot springs of the Rehai geothermal area in Tengchong, Yunnan province. The diversity of Thermus strains was examined by sequencing the 16S rRNA genes and comparing their sequences. Phylogenetic analysis showed that the 16S rDNA sequences from the Rehai geothermal isolates form four branches in the phylogenetic tree and had greater than 95.9% similarity in the phylogroup. Secondary structure comparison also indicated that the 16S rRNA from the Rehai geothermal isolates have unique secondary structure characteristics in helix 6, helix 9, and helix 10 (reference to Escherichia coli). This research is the first attempt to reveal the diversity of Thermus strains that are distributed in the Rehai geothermal area.Key words: Thermus, diversity, phylogenetic analysis, RNA secondary structure.

scholarly journals Feasibility of Transferring Fluorescent In Situ Hybridization Probes to an 18S rRNA Gene Phylochip and Mapping of Signal Intensities

2008 ◽  
Vol 74 (9) ◽  
pp. 2814-2821 ◽  
Author(s):  
Katja Metfies ◽  
Linda K. Medlin
Keyword(s):  
In Situ Hybridization ◽  
Secondary Structure ◽  
16S Rrna ◽  
Fluorescent In Situ Hybridization ◽  
18S Rrna ◽  
18S Rrna Gene ◽  
Rrna Gene ◽  
Rrna Molecule ◽  
The 16S Rrna Gene

ABSTRACT DNA microarray technology offers the possibility to analyze microbial communities without cultivation, thus benefiting biodiversity studies. We developed a DNA phylochip to assess phytoplankton diversity and transferred 18S rRNA probes from dot blot or fluorescent in situ hybridization (FISH) analyses to a microarray format. Similar studies with 16S rRNA probes have been done determined that in order to achieve a signal on the microarray, the 16S rRNA molecule had to be fragmented, or PCR amplicons had to be <150 bp in length to minimize the formation of a secondary structure in the molecule so that the probe could bind to the target site. We found different results with the 18S rRNA molecule. Four out of 12 FISH probes exhibited false-negative signals on the microarray; eight exhibited strong but variable signals using full-length 18S RNA molecules. A systematic investigation of the probe's accessibility to the 18S rRNA gene was made using Prymenisum parvum as the target. Fourteen additional probes identical to this target covered the regions not tested with existing FISH probes. Probes with a binding site in the first 900 bp of the gene generated positive signals. Six out of nine probes binding in the last 900 bp of the gene produced no signal. Our results suggest that although secondary structure affected probe binding, the effect is not the same for the 18S rRNA gene and the 16S rRNA gene. For the 16S rRNA gene, the secondary structure is stronger in the first half of the molecule, whereas in the 18S rRNA gene, the last half of the molecule is critical. Probe-binding sites within 18S rRNA gene molecules are important for the probe design for DNA phylochips because signal intensity appears to be correlated with the secondary structure at the binding site in this molecule. If probes are designed from the first half of the 18S rRNA molecule, then full-length 18S rRNA molecules can be used in the hybridization on the chip, avoiding the fragmentation and the necessity for the short PCR amplicons that are associated with using the 16S rRNA molecule. Thus, the 18S rRNA molecule is a more attractive molecule for use in environmental studies where some level of quantification is desired. Target size was a minor problem, whereas for 16S rRNA molecules target size rather than probe site was important.

scholarly journals Assessment of Genetic Diversity and Symbiotic Efficiency of Selected Rhizobia Strains Nodulating Lentil (Lens culinaris Medik.)

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 15
Author(s):  
Badreddine Sijilmassi ◽  
Abdelkarim Filali-Maltouf ◽  
Hassan Boulahyaoui ◽  
Aymane Kricha ◽  
Kenza Boubekri ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Phylogenetic Analysis ◽  
16S Rrna ◽  
Rhizobium Leguminosarum ◽  
Sequence Similarity ◽  
P Value ◽  
Rrna Gene ◽  
Research Station ◽  
Symbiotic Efficiency ◽  
Rhizobium Strains

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.

scholarly journals The Termite Group I Phylum Is Highly Diverse and Widespread in the Environment

2007 ◽  
Vol 73 (20) ◽  
pp. 6682-6685 ◽  
Author(s):  
Daniel P. R. Herlemann ◽  
Oliver Geissinger ◽  
Andreas Brune
Keyword(s):  
Phylogenetic Analysis ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Specific Primers ◽  
Environmental Distribution ◽  
Data Set ◽  
Group I

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.

scholarly journals Diversity unearthed by the estimated molecular phylogeny and ecologically quantitative characteristics of uncultured Ehrlichia bacteria in Haemaphysalis ticks, Japan

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hongru Su ◽  
Eri Onoda ◽  
Hitoshi Tai ◽  
Hiromi Fujita ◽  
Shigetoshi Sakabe ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
16S Rrna ◽  
Core Genome ◽  
Phylogenetic Analyses ◽  
Taxonomic Status ◽  
Housekeeping Genes ◽  
Pcr Screening ◽  
Taxonomic Profiling ◽  
Quantitative Characteristics

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.

scholarly journals Denitratisoma oestradiolicum gen. nov., sp. nov., a 17β-oestradiol-degrading, denitrifying betaproteobacterium

2006 ◽  
Vol 56 (7) ◽  
pp. 1547-1552 ◽  
Author(s):  
Michael Fahrbach ◽  
Jan Kuever ◽  
Ruth Meinke ◽  
Peter Kämpfer ◽  
Juliane Hollender
Keyword(s):  
Phylogenetic Analysis ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Sequence ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
16S Rrna Gene Sequence ◽  
Physiological Data ◽  
Rrna Gene ◽  
Rrna Gene Sequence

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.

scholarly journals Phylogenetic analysis and secondary structure of the Bacillus subtilis bacteriophage RNA required for DNA packaging.

1990 ◽  
Vol 265 (36) ◽  
pp. 22365-22370
Author(s):  
S Bailey ◽  
J Wichitwechkarn ◽  
D Johnson ◽  
B E Reilly ◽  
D L Anderson ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Bacillus Subtilis ◽  
Secondary Structure ◽  
Dna Packaging ◽  
Subtilis Bacteriophage

scholarly journals Description of Sphingobium fuliginis sp. nov., a phenanthrene-degrading bacterium from a fly ash dumping site, and reclassification of Sphingomonas cloacae as Sphingobium cloacae comb. nov.

2006 ◽  
Vol 56 (9) ◽  
pp. 2147-2152 ◽  
Author(s):  
Om Prakash ◽  
Rup Lal
Keyword(s):  
Phylogenetic Analysis ◽  
Fatty Acid ◽  
Fly Ash ◽  
16S Rrna ◽  
Dna Hybridization ◽  
Type Strain ◽  
Rrna Gene ◽  
16S Rrna Gene Sequences ◽  
Dumping Site ◽  
Degrading Bacterium

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).

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