scholarly journals Genetic diversity and phylogeny of rhizobia isolated from agroforestry legume species in southern Ethiopia

2005 ◽  
Vol 55 (4) ◽  
pp. 1439-1452 ◽  
Author(s):  
Endalkachew Wolde-meskel ◽  
Zewdu Terefework ◽  
Åsa Frostegård ◽  
Kristina Lindström
Keyword(s):  
Genetic Diversity ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Rrna Genes ◽  
Partial Sequence ◽  
23S Rrna ◽  
Southern Ethiopia ◽  
Rrna Gene ◽  
Pcr Rflp ◽  
23S Rrna Gene

The genetic diversity within 195 rhizobial strains isolated from root nodules of 18 agroforestry species (15 woody and three herbaceous legumes) growing in diverse ecoclimatic zones in southern Ethiopia was investigated by using PCR–RFLP of the ribosomal operon [16S rRNA gene, 23S rRNA gene and the internal transcribed spacer (ITS) region between the 16S rRNA and 23S rRNA genes] and 16S rRNA gene partial sequence (800 and 1350 bp) analyses. All of the isolates and the 28 reference strains could be differentiated by using these methods. The size of the ITS varied among test strains (500–1300 bp), and 58 strains contained double copies. UPGMA dendrograms generated from cluster analyses of the 16S and 23S rRNA gene PCR–RFLP data were in good agreement, and the combined distance matrices delineated 87 genotypes, indicating considerable genetic diversity among the isolates. Furthermore, partial sequence analysis of 67 representative strains revealed 46 16S rRNA gene sequence types, among which 12 were 100 % similar to those of previously described species and 34 were novel sequences with 94–99 % similarity to those of recognized species. The phylogenetic analyses suggested that strains indigenous to Ethiopia belonged to the genera Agrobacterium, Bradyrhizobium, Mesorhizobium, Methylobacterium, Rhizobium and Sinorhizobium. Many of the rhizobia isolated from previously uninvestigated indigenous woody legumes had novel 16S rRNA gene sequences and were phylogenetically diverse. This study clearly shows that the characterization of symbionts of unexplored legumes growing in previously unexplored biogeographical areas will reveal additional diversity.

scholarly journals Reassessment of the phylogenetic relationships of Thiomonas cuprina

2007 ◽  
Vol 57 (11) ◽  
pp. 2720-2724 ◽  
Author(s):  
Donovan P. Kelly ◽  
Yoshihito Uchino ◽  
Harald Huber ◽  
Ricardo Amils ◽  
Ann P. Wood
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Sequence ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
23S Rrna ◽  
Rrna Gene ◽  
Significant Similarity ◽  
23S Rrna Gene ◽  
The 16S Rrna Gene

The published sequence of the 16S rRNA gene of Thiomonas cuprina strain Hö5 (=DSM 5495T) (GenBank accession no. U67162) was found to be erroneous. The 16S rRNA genes from the type strain held by the DSMZ since 1990 (DSM 5495T =NBRC 102145T) and strain Hö5 maintained frozen in the Universität Regensburg for 23 years (=NBRC 102094) were sequenced and found to be identical, but to show no significant similarity to the U67162 sequence. This also casts some doubt on the previously published 5S and 23S rRNA gene sequences (GenBank accession nos U67171 and X75567). The correct 16S rRNA gene sequence showed 99.8 % identity to those from Thiomonas delicata NBRC 14566T and ‘Thiomonas arsenivorans’ DSM 16361. The properties of these three species are re-evaluated, and emended descriptions are provided for the genus Thiomonas and the species Thiomonas cuprina.

scholarly journals Discordant 16S and 23S rRNA Gene Phylogenies for the Genus Helicobacter: Implications for Phylogenetic Inference and Systematics

2005 ◽  
Vol 187 (17) ◽  
pp. 6106-6118 ◽  
Author(s):  
Floyd E. Dewhirst ◽  
Zeli Shen ◽  
Michael S. Scimeca ◽  
Lauren N. Stokes ◽  
Tahani Boumenna ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Sequence ◽  
Sequence Data ◽  
Rrna Genes ◽  
23S Rrna ◽  
Rrna Gene ◽  
Rrna Gene Sequence ◽  
23S Rrna Gene ◽  
23S Rrna Genes

ABSTRACT Analysis of 16S rRNA gene sequences has become the primary method for determining prokaryotic phylogeny. Phylogeny is currently the basis for prokaryotic systematics. Therefore, the validity of 16S rRNA gene-based phylogenetic analyses is of fundamental importance for prokaryotic systematics. Discrepancies between 16S rRNA gene analyses and DNA-DNA hybridization and phenotypic analyses have been noted in the genus Helicobacter. To clarify these discrepancies, we sequenced the 23S rRNA genes for 55 helicobacter strains representing 41 taxa (>2,700 bases per sequence). Phylogenetic-tree construction using neighbor-joining, parsimony, and maximum likelihood methods for 23S rRNA gene sequence data yielded stable trees which were consistent with other phenotypic and genotypic methods. The 16S rRNA gene sequence-derived trees were discordant with the 23S rRNA gene trees and other data. Discrepant 16S rRNA gene sequence data for the helicobacters are consistent with the horizontal transfer of 16S rRNA gene fragments and the creation of mosaic molecules with loss of phylogenetic information. These results suggest that taxonomic decisions must be supported by other phylogenetically informative macromolecules, such as the 23S rRNA gene, when 16S rRNA gene-derived phylogeny is discordant with other credible phenotypic and genotypic methods. This study found Wolinella succinogenes to branch with the unsheathed-flagellum cluster of helicobacters by 23S rRNA gene analyses and whole-genome comparisons. This study also found intervening sequences (IVSs) in the 23S rRNA genes of strains of 12 Helicobacter species. IVSs were found in helices 10, 25, and 45, as well as between helices 31′ and 27′. Simultaneous insertion of IVSs at three sites was found in H. mesocricetorum.

Differentiation Of Clarias Batrachus, C. Gariepinus And Heteropneustes Fossilis By Pcr-Sequencing Of Mitochondrial 16s Rrna Gene

2015 ◽  
Vol 41 (1) ◽  
pp. 51-58
Author(s):  
Mohammad Shamimul Alam ◽  
Hawa Jahan ◽  
Rowshan Ara Begum ◽  
Reza M Shahjahan
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Fish Larva ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Valuable Insight ◽  
Multiple Sequence ◽  
Pcr Rflp ◽  
Alternative Means

Heteropneustesfossilis, Clariasbatrachus and C. gariepinus are three major catfishes ofecological and economic importance. Identification of these fish species becomes aproblem when the usual external morphological features of the fish are lost or removed,such as in canned fish. Also, newly hatched fish larva is often difficult to identify. PCRsequencingprovides accurate alternative means of identification of individuals at specieslevel. So, 16S rRNA genes of three locally collected catfishes were sequenced after PCRamplification and compared with the same gene sequences available from othergeographical regions. Multiple sequence alignment of the 16S rRNA gene fragments ofthe catfish species has revealed polymorphic sites which can be used to differentiate thesethree species from one another and will provide valuable insight in choosing appropriaterestriction enzymes for PCR-RFLP based identification in future. Asiat. Soc. Bangladesh, Sci. 41(1): 51-58, June 2015

scholarly journals Gluconobacter nephelii sp. nov., an acetic acid bacterium in the class Alphaproteobacteria

2011 ◽  
Vol 61 (9) ◽  
pp. 2117-2122 ◽  
Author(s):  
Jintana Kommanee ◽  
Somboon Tanasupawat ◽  
Pattaraporn Yukphan ◽  
Taweesak Malimas ◽  
Yuki Muramatsu ◽  
...  
Keyword(s):  
Acetic Acid ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Phylogenetic Trees ◽  
23S Rrna ◽  
Rrna Gene ◽  
Phenotypic Data ◽  
Dna Relatedness ◽  
23S Rrna Gene ◽  
Type Strains

Three strains, RBY-1T, PHD-1 and PHD-2, were isolated from fruits in Thailand. The strains were Gram-negative, aerobic rods with polar flagella, produced acetic acid from ethanol and did not oxidize acetate or lactate. In phylogenetic trees based on 16S rRNA gene sequences and 16S–23S rRNA gene internal transcribed spacer (ITS) sequences, the strains formed a cluster separate from the type strains of recognized species of the genus Gluconobacter. The calculated 16S rRNA gene sequence and 16S–23S rRNA gene ITS sequence similarities were respectively 97.7–99.7 % and 77.3–98.1 %. DNA G+C contents ranged from 57.2 to 57.6 mol%. The strains showed high DNA–DNA relatedness of 100 % to one another, but low DNA–DNA relatedness of 11–34 % to the tested type strains of recognized Gluconobacter species. Q-10 was the major quinone. On the basis of the genotypic and phenotypic data obtained, the three strains clearly represent a novel species, for which the name Gluconobacter nephelii sp. nov. is proposed. The type strain is RBY-1T ( = BCC 36733T = NBRC 106061T = PCU 318T), whose DNA G+C content is 57.2 mol%.

scholarly journals Phylogenetic relationships within the family Halomonadaceae based on comparative 23S and 16S rRNA gene sequence analysis

2010 ◽  
Vol 60 (4) ◽  
pp. 737-748 ◽  
Author(s):  
Rafael R. de la Haba ◽  
David R. Arahal ◽  
M. Carmen Márquez ◽  
Antonio Ventosa
Keyword(s):  
16S Rrna ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
23S Rrna ◽  
Rrna Gene ◽  
Gene Sequences ◽  
The Family ◽  
23S Rrna Gene ◽  
Group 2 ◽  
Group 1

A phylogenetic study of the family Halomonadaceae was carried out based on complete 16S rRNA and 23S rRNA gene sequences. Several 16S rRNA genes of type strains were resequenced, and 28 new sequences of the 23S rRNA gene were obtained. Currently, the family includes nine genera (Carnimonas, Chromohalobacter, Cobetia, Halomonas, Halotalea, Kushneria, Modicisalibacter, Salinicola and Zymobacter). These genera are phylogenetically coherent except Halomonas, which is polyphyletic. This genus comprises two clearly distinguished clusters: group 1 includes Halomonas elongata (the type species) and the species Halomonas eurihalina, H. caseinilytica, H. halmophila, H. sabkhae, H. almeriensis, H. halophila, H. salina, H. organivorans, H. koreensis, H. maura and H. nitroreducens. Group 2 comprises the species Halomonas aquamarina, H. meridiana, H. axialensis, H. magadiensis, H. hydrothermalis, H. alkaliphila, H. venusta, H. boliviensis, H. neptunia, H. variabilis, H. sulfidaeris, H. subterranea, H. janggokensis, H. gomseomensis, H. arcis and H. subglaciescola. Halomonas salaria forms a cluster with Chromohalobacter salarius and the recently described genus Salinicola, and their taxonomic affiliation requires further study. More than 20 Halomonas species are phylogenetically not within the core constituted by the Halomonas sensu stricto cluster (group 1) or group 2 and, since their positions on the different phylogenetic trees are not stable, they cannot be recognized as additional groups either. In general, there is excellent agreement between the phylogenies based on the two rRNA gene sequences, but the 23S rRNA gene showed higher resolution in the differentiation of species of the family Halomonadaceae.

Psychrobacter sanguinis sp. nov., recovered from four clinical specimens over a 4-year period

2012 ◽  
Vol 62 (1) ◽  
pp. 49-54 ◽  
Author(s):  
Samantha E. Wirth ◽  
Héctor L. Ayala-del-Río ◽  
Jocelyn A. Cole ◽  
Donna J. Kohlerschmidt ◽  
Kimberlee A. Musser ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Novel Species ◽  
Sequence Similarity ◽  
23S Rrna ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
23S Rrna Gene ◽  
Reference Specimens

An analysis of 16S rRNA gene sequences from archived clinical reference specimens identified a novel species of the genus Psychrobacter, of which four strains have been independently isolated from human blood. On the basis of 16S rRNA gene sequence similarity, the closest relatives with validly published names were Psychrobacter arenosus R7T (98.7 %), P. pulmonis CECT 5989T (97.7 %), P. faecalis Iso-46T (97.6 %) and P. lutiphocae IMMIB L-1110T (97.2 %). Maximum-likelihood phylogenetic analysis of 16S rRNA gene sequences showed that the isolates belonged to the genus Psychrobacter and were members of a cluster associated with Psychrobacter sp. PRwf-1, isolated from a silk snapper fish. DNA–DNA relatedness and partial 23S rRNA gene sequences also supported the finding that the isolates belonged to a species distinct from its closest phylogenetic neighbours. The predominant cellular fatty acids were C18 : 1ω9c, C16 : 0, summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), summed feature 5 (C18 : 2ω6,9c and/or anteiso-C18 : 0) and C18 : 0. Biochemical and morphological analysis further supported the assignment of the four isolates to a novel species. The name Psychrobacter sanguinis sp. nov. is proposed. The type strain is 13983T ( = DSM 23635T = CCUG 59771T).

scholarly journals Identification of Mycobacterium kansasiiby Using a DNA Probe (AccuProbe) and Molecular Techniques

1999 ◽  
Vol 37 (4) ◽  
pp. 964-970 ◽  
Author(s):  
Elvira Richter ◽  
Stefan Niemann ◽  
Sabine Rüsch-Gerdes ◽  
Sven Hoffner
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Restriction Pattern ◽  
Molecular Techniques ◽  
Rrna Genes ◽  
23S Rrna ◽  
Rrna Gene ◽  
Genetic Analyses ◽  
New Formulation ◽  
The 16S Rrna Gene

The newly formulated Mycobacterium kansasii AccuProbe was evaluated, and the results obtained with the new version were compared to the results obtained with the old version of this test by using 116 M. kansasii strains, 1 Mycobacterium gastri strain, and 19 strains of several mycobacterial species. The sensitivity of this new formulation was 97.4% and the specificity was 100%. Still, three M. kansasii strains were missed by this probe. To evaluate the variability within the species, genetic analyses of the hsp65 gene, the spacer sequence between the 16S and 23S rRNA genes, and the 16S rRNA gene of several M. kansasii AccuProbe-positive strains as well as all AccuProbe-negative strains were performed. Genetic analyses of the oneM. gastri strain from the comparative assay and of two further M. gastri strains were included because of the identity of the 16S rRNA gene in M. gastri to that inM. kansasii. The data confirmed the genetic heterogeneity of M. kansasii. Furthermore, a subspecies with an unpublished hsp65 restriction pattern and spacer sequence was described. The genetic data indicate that all M. kansasii strains missed by the AccuProbe test belong to one subspecies, the newly described subspecies VI, as determined by thehsp65 restriction pattern and the spacer sequence. Since the M. kansasii strains that are missed are rare and allM. gastri strains are correctly negative, the new formulated AccuProbe provides a useful tool for the identification ofM. kansasii.

scholarly journals Establishment of the family Zarkiaceae (Oscillatoriales, Cyanobacteria) and description of the new marine genera Zarkia (Zarkiaceae, Oscillatoriales) and Romeriopsis (Leptolyngbyaceae, Synechococcales), from northern Portugal

2021 ◽  
Author(s):  
Guilherme S. Hentschke ◽  
Angela Pinheiro ◽  
Vitor Ramos ◽  
Aldo Barreiro ◽  
M. Sofia Costa ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Secondary Structures ◽  
Morphological Characters ◽  
23S Rrna ◽  
Rrna Gene ◽  
New Family ◽  
The Family ◽  
23S Rrna Gene ◽  
Taxonomical Revision

The morphology, 16S rRNA gene phylogeny and the 16S-23S rRNA gene ITS secondary structures of three strains of marine Cyanobacteria, isolated from inter- and subtidal environments from north Portugal were studied, resulting in the description of Zarkia subtidalensis gen. et. sp. nov. (Zarkiaceae fam. nov.) and Romeriopsis marina gen. et. sp. nov (Leptolyngbyaceae). No diacritical morphological characters were found either for the new family or for the new genera. The 16S rRNA gene Maximum Likelihood and Bayesian phylogenies supported that Zarkia and Zarkiaceae are members of the Oscillatoriales, positioned close to Microcoleaceae genera, but distant from Microcoleus. Romeriopsis is positioned within the Leptolyngbyaceae and is closely related to Alkalinema. The secondary structures of the D1-D1′, Box B, V2 and V3 helices corroborate with the phylogenetic results. Furthermore, our study supports previous observations of polyphyletic Oscillatoriales families and reinforces the need for their taxonomical revision.

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