Bacterial and archaeal 16S rDNA and 16S rRNA dynamics during an acetate crisis in an anaerobic digestor ecosystem

2001 ◽  
Vol 35 (1) ◽  
pp. 19-26 ◽  
Author(s):  
C Delbès
Keyword(s):  
16S Rrna ◽  
16S Rdna ◽  
Anaerobic Digestor

scholarly journals Bacterial and archaeal 16S rDNA and 16S rRNA dynamics during an acetate crisis in an anaerobic digestor ecosystem

2001 ◽  
Vol 35 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Céline Delbès ◽  
René Moletta ◽  
Jean-Jacques Godon
Keyword(s):  
16S Rrna ◽  
16S Rdna ◽  
Anaerobic Digestor

scholarly journals Molecular Diversity Assessment of Plant Growth Promoting Rhizobacteria Using Denaturing Gradient Gel Electrophoresis (DGGE) of 16s rRNA Gene

2017 ◽  
Vol 5 (1) ◽  
pp. 72-80
Author(s):  
Umesh Prasad Shrivastava
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
16S Rdna ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Uttar Pradesh ◽  
Plant Growth Promoting Rhizobacteria ◽  
Melting Behavior ◽  
Rrna Gene ◽  
Dgge Profile ◽  
Diversity Assessment

The rhizobacteria were isolated from rhizosphere of rice plant of different fields of 4 districts of Nepal and 5 districts of Bihar and Uttar Pradesh, adjoining states of India with Nepal. The DGGE analysis was performed for diversity analysis. For the construction of dendrogram, 16S rRNA gene was amplified by two different sets of primers. The DGGE ladder consisting of PCR amplified products of nine pure bacterial cultures were obtained. The first DGGE ladder was prepared by 400 bp fragment of 16S rDNA with GC clamp and the second DGGE ladder was prepared with 200 bp fragment of 16S rDNA with GC clamp. The perpendicular DGGE of these amplicons based on their melting behavior clearly demonstrated separation of different isolates. The 16S rDNA fragment amplified with primer set of V2-V3 regions with GC clamp showed separation between 40-60% of denaturant. The DGGE profile based on primer set F352T and 519r for various bacteria present in soil samples of 5 districts of India and 4 districts of Nepal revealed that the number of bands which might be specific for diazotrophic isolates varied from 2 to 11. The dendrogram constructed based on DGGE profile of various samples of 5 districts of India and 4 districts of Nepal showed that all the samples could be clustered in nine groups with 58-96% similarity to each other. Among all these 37 samples, only Var-4 and Var-5 showed 100% similarity, no other samples from any site showed 100% similarity. Int. J. Appl. Sci. Biotechnol. Vol 5(1): 72-80

scholarly journals Prevalence of the Rhizobium etli-Like Allele in Genes Coding for 16S rRNA among the Indigenous Rhizobial Populations Found Associated with Wild Beans from the Southern Andes in Argentina

1998 ◽  
Vol 64 (9) ◽  
pp. 3520-3524 ◽  
Author(s):  
O. Mario Aguilar ◽  
María Verónica López ◽  
Pablo M. Riccillo ◽  
Ramón A. González ◽  
Marcela Pagano ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rdna ◽  
Rhizobium Leguminosarum ◽  
Symbiotic Association ◽  
Rhizobium Etli ◽  
Center Of Origin ◽  
Wild Bean ◽  
Northwest Argentina ◽  
Bean Plants ◽  
Wild Beans

ABSTRACT A collection of rhizobial isolates from nodules of wild beans,Phaseolus vulgaris var. aborigineus, found growing in virgin lands in 17 geographically separate sites in northwest Argentina was characterized on the basis of host range, growth, hybridization to a nifH probe, analysis of genes coding for 16S rRNA (16S rDNA), DNA fingerprinting, and plasmid profiles. Nodules in field-collected wild bean plants were largely dominated by rhizobia carrying the 16S rDNA allele of Rhizobium etli. A similar prevalence of the R. etli allele was observed among rhizobia trapped from nearby soil. Intragroup diversity of wild bean isolates with either R. etli-like or Rhizobium leguminosarum bv. phaseoli-like alleles was generally found across northwest Argentina. The predominance of the R. etliallele suggests that in this center of origin of P. vulgaris the coevolution of Rhizobium spp. and primitive beans has resulted in this preferential symbiotic association.

scholarly journals Comparison of Different DNA Fingerprinting Techniques for Molecular Typing of Bartonella henselaeIsolates

1998 ◽  
Vol 36 (10) ◽  
pp. 2973-2981 ◽  
Author(s):  
Anna Sander ◽  
Michael Ruess ◽  
Stefan Bereswill ◽  
Markus Schuppler ◽  
Bernhard Steinbrueckner
Keyword(s):  
16S Rrna ◽  
16S Rdna ◽  
Dna Fingerprinting ◽  
Genetic Heterogeneity ◽  
Bartonella Henselae ◽  
Specific Pcr ◽  
Rdna Sequences ◽  
16S Rdna Sequences ◽  
Specific Amplification ◽  
Clear Differentiation

Seventeen isolates of Bartonella henselae from the region of Freiburg, Germany, obtained from blood cultures of domestic cats, were examined for their genetic heterogeneity. On the basis of different DNA fingerprinting methods, including pulsed-field gel electrophoresis (PFGE), enterobacterial repetitive intergenic consensus (ERIC)-PCR, repetitive extragenic palindromic (REP) PCR, and arbitrarily primed (AP)-PCR, three different variants were identified among the isolates (variants I to III). Variant I included 6 strains, variant II included 10 strains, and variant III included only one strain. By all methods used, the isolates could be clearly distinguished from the type strain, Houston-1, which was designated variant IV. A previously published type-specific amplification of 16S rDNA differentiated two types of the B. henselaeisolates (16S rRNA types 1 and 2). The majority of the isolates (16 of 17), including all variants I and II, were 16S rRNA type 2. Only one isolate (variant III) and the Houston-1 strain (variant IV) comprised the 16S rRNA type 1. Comparison of the 16S rDNA sequences from one representative strain from each of the three variants (I to III) confirmed the results obtained by 16S rRNA type-specific PCR. The sequences from variant I and variant II were identical, whereas the sequence of variant III differed in three positions. All methods applied in this study allowed subtyping of the isolates. PFGE and ERIC-PCR provided the highest discriminatory potential for subtypingB. henselae strains, whereas AP-PCR with the M13 primer showed a very clear differentiation between the four variants. Our results suggest that the genetic heterogeneity of B. henselae strains is high. The methods applied were found useful for typing B. henselae isolates, providing tools for epidemiological and clinical follow-up studies.

scholarly journals Phenotypic characterization of Astragalus glycyphyllos symbionts and their phylogeny based on the 16S rDNA sequences and RFLP of 16S rRNA gene

2014 ◽  
Vol 105 (6) ◽  
pp. 1033-1048 ◽  
Author(s):  
Sebastian Gnat ◽  
Magdalena Wójcik ◽  
Sylwia Wdowiak-Wróbel ◽  
Michał Kalita ◽  
Aneta Ptaszyńska ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
16S Rdna ◽  
Phenotypic Characterization ◽  
Rrna Gene ◽  
Rdna Sequences ◽  
16S Rdna Sequences ◽  
Astragalus Glycyphyllos Symbionts

Intra-chromosomal heterogeneity between the four 16S rRNA gene copies in the genus Veillonella: implications for phylogeny and taxonomy

Microbiology ◽  
2003 ◽  
Vol 149 (6) ◽  
pp. 1493-1501 ◽  
Author(s):  
Hélène Marchandin ◽  
Corinne Teyssier ◽  
Michèle Siméon de Buochberg ◽  
Hélène Jean-Pierre ◽  
Christian Carriere ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rdna ◽  
Clinical Isolates ◽  
Clinical Strain ◽  
Species Differentiation ◽  
Rrna Gene ◽  
Rdna Sequences ◽  
Gene Copies ◽  
High Level ◽  
Human Flora

Among the seven species characterized within the genus Veillonella, three (Veillonella dispar, Veillonella parvula and Veillonella atypica) have so far been isolated from human flora and during infectious processes. Sequencing and analysis of 16S rDNA (rrs) has been described as the best method for identification of Veillonella strains at the species level since phenotypic characteristics are unable to differentiate between species. rrs sequencing for the three species isolated from humans showed more than 98 % identity between them. Four rrs copies were found in the reference strains and in all the clinical isolates studied. The sequences of each rrs were determined for the clinical strain ADV 360.1, and they showed a relatively high level of heterogeneity (1·43 %). In the majority of cases, polymorphic positions corresponded to nucleotides allowing differentiation between the three species isolated from humans. Moreover, variability observed between rrs copies was higher than that between 16S rDNA sequences of V. parvula and V. dispar. Phylogenetic analysis showed that polymorphism between rrs copies affected the position of strain ADV 360.1 in the tree. Variable positions occurred in stems and loops belonging to variable and hypervariable regions of the 16S rRNA secondary structure but did not change the overall structure of the 16S rRNA. PCR-RFLP experiments performed on 27 clinical isolates of Veillonella sp. suggested that inter-rrs heterogeneity occurs widely among the members of the genus Veillonella. These results, together with the lack of phenotypic criteria for species differentiation, give preliminary arguments for unification of V. dispar and V. parvula.

scholarly journals rDNA analyses of planktonic heterocystous cyanobacteria, including members of the genera Anabaenopsis and Cyanospira The GenBank accession numbers of the 16S rDNA gene sequences reported in this paper are AY038032–AY038037.

Microbiology ◽  
2002 ◽  
Vol 148 (2) ◽  
pp. 481-496 ◽  
Author(s):  
Isabelle Iteman ◽  
Rosmarie Rippka ◽  
Nicole Tandeau de Marsac ◽  
Michael Herdman
Keyword(s):  
16S Rrna ◽  
16S Rdna ◽  
Genomic Sequence ◽  
Sequence Similarity ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
23S Rrna ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
Heterocystous Cyanobacteria

The taxonomic coherence and phylogenetic relationships of 11 planktonic heterocystous cyanobacterial isolates were examined by investigating two areas of the rRNA operon, the 16S rRNA gene (rrnS) and the internal transcribed spacer (ITS) located between the 16S rRNA and 23S rRNA genes. The rrnS sequences were determined for five strains, including representatives of Anabaena flos-aquae, Aphanizomenon flos-aquae, Nodularia sp. and two alkaliphilic planktonic members of the genera Anabaenopsis and Cyanospira, whose phylogenetic position was previously unknown. Comparison of the data with those previously published for individual groups of planktonic heterocystous cyanobacteria showed that, with the exception of members assigned to the genus Cylindrospermopsis, all the planktonic strains form a distinct subclade within the monophyletic clade of heterocystous cyanobacteria. Within this subclade five different phylogenetic clusters were distinguished. The phylogenetic groupings of Anabaena and Aphanizomenon strains within three of these clusters were not always consistent with their generic or specific assignments based on classical morphological definitions, and the high degree of sequence similarity between strains of Anabaenopsis and Cyanospira suggests that they may be assignable to a single genus. Ribotyping and additional studies performed on PCR amplicons of the 16S rDNA or the ITS for the 11 planktonic heterocystous strains demonstrated that they all contain multiple rrn operons and ITS regions of variable size. Finally, evidence is provided for intra-genomic sequence heterogeneity of the 16S rRNA genes within most of the individual isolates.

scholarly journals Cryptic haplotypes of "Candidatus Liberibacter africanus"

2015 ◽  
Author(s):  
Warrick Nelson ◽  
Sandrine Eveillard ◽  
Marie-Pierre Dubrana ◽  
Joseph Bové
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
16S Rdna ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Rdna Sequences ◽  
New Information ◽  
Candidatus Liberibacter ◽  
Citrus Leaves

“Candidatus Liberibacter africanus” (Laf) has long been recognised as a causal agent of the devastating citrus disease huanglongbing (HLB) or citrus greening. This species is currently restricted to Africa, the Arabian Peninsula and some Indian Ocean islands and vectored by the African citrus psyllid, Trioza erytreae. Blotchy mottle on citrus leaves is characteristic of the disease. Somewhat similar symptoms in the Rutaceous tree Calodendrum capensis (Cape Chestnut) resulted in the discovery of Laf outside commercial citrus crops in South Africa. This was classed as a subspecies of Laf (capensis, hence LafC). In subsequent surveys of both commercial citrus crops and Calodendrum, both natural and ornamental specimens, LafC was not found in the citrus crop, nor has Laf been found in C. capensis. HLB was reported from Madagascar in 1968 but no sequences from this source have so far been published. Until fairly recently, only the reference 16S rRNA gene sequences of Laf (L22533) and LafC (AF137368) had been deposited in GenBank. Both of these reference sequences contain a number of unresolved nucleotides. Resolving these nucleotide positions by aligning against more recently available sequences, it becomes evident that these unresolved positions represent one percentage point difference in similarity between Laf and LafC. The originally reported 97.4% similarity is therefore incorrect based on this new information. Recalculating the similarity on the full length 16S rDNA sequence results in 99.54% similarity, a value too high to justify a subspecies status. LafC should therefore be reduced to that of a haplotype of Laf. Further, the six 16S rRNA gene sequences currently available in GenBank identified as the species Laf separate into 2 haplotype groups. The 3 haplotypes of Laf are therefore LafA designated as the first accession sequenced (L22533), LafC for the former capensis subspecies and to recognise the prior use of this term, and LafB for the third haplotype not previously recognised. Thus the cryptic presence of 3 haplotypes is revealed by this review of the Laf 16S rDNA sequences.

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