scholarly journals Amplification of 16S rRNA gene sequences to differentiate two highly related bradyrhizobia species

2007 ◽  
Vol 42 (9) ◽  
pp. 1361-1364 ◽  
Author(s):  
Adriana Giongo ◽  
Adriana Ambrosini ◽  
João Ruy Jardim Freire ◽  
Maria Helena Bodanese Zanettini ◽  
Luciane Maria Pereira Passaglia

A 16S rRNA gene PCR-based assay was developed aiming at a fast molecular diagnostic method to differentiate the two phylogenetically closely related species Bradyrhizobium japonicum and B. elkanii, isolated from soybean nodules, in order to identify those more competitive and comprising greater nitrogen fixation ability for use in the formulation of commercial inoculants. The assay used was able to discriminate ten reference strains belonging to these two Bradyrhizobium species, as well as to efficiently identify 37 strains isolated from fields cultivated with soybean.

2017 ◽  
Vol 3 ◽  
Author(s):  
TIANYU GUO ◽  
YI SUN ◽  
GUANG XU ◽  
LANCE A. DURDEN

SUMMARY The female and nymph of Ixodes (Pholeoixodes) kangdingensis n. sp. are described based on both morphology and analysis of 16S rRNA gene sequences. Specimens of this new tick species were collected from a Siberian weasel (Mustela sibirica) in Kangding County, Sichuan Province, China. The morphological features of the female and nymph are unique to distinguish I. kangdingensis n. sp. from other members of the subgenus Pholeoixodes, including the presence of distinctly shaped cornua, anterior and posterior processes on palpal article I and a large angular projection on each side of the hypostome. Partial sequence of 16S rRNA gene grouped this species with Ixodes arboricola and Ixodes lividus with sequence divergence of new species from I. arboricola 4·16% and from I. lividus 8·49%. Data on the phylogenetic position, hosts, geographic distribution and key to females of closely related species are also provided.


2014 ◽  
Vol 64 (Pt_6) ◽  
pp. 2072-2078 ◽  
Author(s):  
David Durán ◽  
Luis Rey ◽  
Juan Mayo ◽  
Doris Zúñiga-Dávila ◽  
Juan Imperial ◽  
...  

A group of strains isolated from root nodules of Phaseolus lunatus (Lima bean) in Peru were characterized by genotypic, genomic and phenotypic methods. All strains possessed identical 16S rRNA gene sequences that were 99.9 % identical to that of Bradyrhizobium lablabi CCBAU 23086T. Despite having identical 16S rRNA gene sequences, the Phaseolus lunatus strains could be divided into two clades by sequence analysis of recA, atpD, glnII, dnaK and gyrB genes. The genome sequence of a representative of each clade was obtained and compared to the genomes of closely related species of the genus Bradyrhizobium . Average nucleotide identity values below the species circumscription threshold were obtained when comparing the two clades to each other (88.6 %) and with all type strains of the genus Bradyrhizobium (≤92.9 %). Phenotypes distinguishing both clades from all described and closely related species of the genus Bradyrhizobium were found. On the basis of the results obtained, two novel species, Bradyrhizobium paxllaeri sp. nov. (type strain LMTR 21T = DSM 18454T = HAMBI 2911T) and Bradyrhizobium icense sp. nov. (type strain LMTR 13T = HAMBI 3584T = CECT 8509T = CNPSo 2583T), are proposed to accommodate the uncovered clades of Phaseolus lunatus bradyrhizobia. These species share highly related but distinct nifH and nodC symbiosis genes.


2005 ◽  
Vol 55 (5) ◽  
pp. 2007-2011 ◽  
Author(s):  
Fernando Martínez-Checa ◽  
Victoria Béjar ◽  
M. José Martínez-Cánovas ◽  
Inmaculada Llamas ◽  
Emilia Quesada

Halomonas almeriensis sp. nov. is a Gram-negative non-motile rod that was isolated from a saltern in the Cabo de Gata-Níjar wildlife reserve in Almería, south-east Spain. It is moderately halophilic, capable of growth at concentrations of 5–25 % w/v sea-salt mixture, the optimum being 7·5 % w/v. It is chemo-organotrophic and strictly aerobic, produces catalase but not oxidase, does not produce acid from any sugar and does not synthesize hydrolytic enzymes. The most notable difference between this micro-organism and other Halomonas species is that it is very fastidious in its use of a carbon source. It forms mucoid colonies due to the production of an exopolysaccharide. Its G+C content is 63·5 mol%. A comparison of 16S rRNA gene sequences confirmed its relationship to Halomonas species. The most closely related species is Halomonas halmophila with 95·8 % similarity between their 16S rRNA gene sequences. DNA–DNA hybridization with H. halmophila is 10·1 %. Its major fatty acids are 18 : 1ω7c, 16 : 0, 16 : 1ω7c/15 : 0 iso 2-OH, 12 : 0 3-OH, 12 : 0, 11-methyl 18 : 1ω7c and 10 : 0. The proposed name is Halomonas almeriensis sp. nov., with strain M8T (=CECT 7050T=LMG 22904T) as the type strain.


2015 ◽  
Vol 65 (Pt_11) ◽  
pp. 4244-4249 ◽  
Author(s):  
Sooyeon Park ◽  
Sona Kim ◽  
Yong-Taek Jung ◽  
Jung-Hoon Yoon

A Gram-stain-negative, aerobic, non-spore-forming bacterial strain, motile by gliding and with rod-shaped or ovoid cells, was isolated from water of an estuary environment at Hwajinpo, South Korea. The strain was designated HJM-19T and subjected to a polyphasic taxonomic study. The novel strain grew optimally at 30 °C, at pH 7.0–8.0 and in the presence of 1.0–2.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain HJM-19T belongs to the genus Gramella. It exhibited 16S rRNA gene sequence similarity values of 97.2–98.1 % to the type strains of Gramella portivictoriae, Gramella aestuariivivens, Gramella marina, Gramella echinicola and Gramella aestuarii, and of 93.9–96.5 % to the type strains of the other species of the genus Gramella with validly published names. Strain HJM-19T contained MK-6 as the predominant menaquinone and anteiso-C15 : 0, anteiso-C17 : 1ω9c and C17 : 0 2-OH as the major fatty acids. The major polar lipids of strain HJM-19T were phosphatidylethanolamine and two unidentified lipids. The DNA G+C content of strain HJM-19T was 48.0 mol%, and its DNA–DNA relatedness values with the type strains of the five phylogenetically closely related species of the genus Gramella were 11–23 %. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain HJM-19T is separated from other species of the genus Gramella. On the basis of the data presented, strain HJM-19T is considered to represent a novel species of the genus Gramella, for which the name Gramella aquimixticola sp. nov. is proposed. The type strain is HJM-19T ( = KCTC 42706T = NBRC 111224T).


2006 ◽  
Vol 56 (7) ◽  
pp. 1525-1529 ◽  
Author(s):  
Melissa M. Kendall ◽  
Yitai Liu ◽  
Magdalena Sieprawska-Lupa ◽  
Karl O. Stetter ◽  
William B. Whitman ◽  
...  

Three strains of CO2-reducing methanogens were isolated from marine sediments. Strain PL-15/HP was isolated from marine sediments of the Lipari Islands, near Sicily and the other two strains, Nankai-2 and Nankai-3T, were isolated from deep marine sediments of the Nankai Trough, about 50 km from the coast of Japan. Analysis of the cellular proteins and 16S rRNA gene sequences indicated that these three strains represented a single novel species that formed a deep branch of the mesophilic methanococci. Phylogenetic analysis indicated that the three strains were most closely related to Methanothermococcus okinawensis (95 % 16S rRNA gene sequence similarity). However, strains PL-15/HP, Nankai-2 and Nankai-3T grew at temperatures that were more similar to those of recognized species within the genus Methanococcus. Strain Nankai-3T grew fastest at 46 °C. Results of physiological and biochemical tests allowed the genotypic and phenotypic differentiation of strains PL-15/HP, Nankai-2 and Nankai-3T from closely related species. The name Methanococcus aeolicus sp. nov. is proposed, with strain Nankai-3T (=OCM 812T=DSM 17508T) as the type strain.


2021 ◽  
Author(s):  
Seung-Hyeon Choi ◽  
Ji Young Choi ◽  
Jam-Eon Park ◽  
Ji-Sun Kim ◽  
Se Won Kang ◽  
...  

Abstract A novel, strictly anaerobic, gram-negative, segmented filamentous bacterium (SFB), strain AGMB03513T, was isolated from the faeces of a 5-month-old pig. Comparative analysis of 16S rRNA gene sequences indicated that strain AGMB03513T forms a lineage within the genus Anaerostipes and is most closely related to Anaerostipes butyraticus DSM 22094T (= KCTC 15125T, 95.8%), Anaerostipes hadrus DSM 3319T (= KCTC 15606T, 95.5%), Anaerostipes caccae DSM 14662T (= KCTC 15019T, 94.0%), and Anaerostipes rhamnosivorans DSM 26241T (= KCTC 15316T, 93.4%). Phylogenetic analysis based on the 16S rRNA gene and whole genome sequencing analysis revealed that its closest relatives are members of the family Lachnospiraceae and that the closest related is Anaerostipes butyraticus. Strain AGMB03513T grows at temperatures of between 30 and 45°C within a pH range of 7.0 to 9.0, and in medium containing up to 1.5% NaCl. Cells were found to utilize d-glucose, d-mannitol, d-lactose, d-saccharose, d-maltose, d-xylose, l-arabinose, d-mannose, and d-sorbitol, and acetate was identified as the major end product of metabolism. The DNA G+C content of the strain is 37.0 mol%. Average nucleotide identity (ANI) values obtained in comparisons of strain AGMB03513T with reference strains of species in the genus Anaerostipes were between 71.0% and 75.7%, which are below the ANI criterion for interspecies identity. The major components of cellular fatty acids were C12:0, C16:0, and C18:0. On the basis of phenotypic, phylogenetic, biochemical, chemotaxonomic, and genomic characteristics, we consider it reasonable to assign novel species status to strain AGMB03513T, for which we propose the name Anaerostipes faecalis sp. nov. The type strain AGMB03513T (=KCTC 25020T=NBRC 114896T).


2020 ◽  
Author(s):  
CC Kim ◽  
WJ Kelly ◽  
ML Patchett ◽  
GW Tannock ◽  
Z Jordens ◽  
...  

© 2017 IUMS. A novel anaerobic pectinolytic bacterium (strain 14T) was isolated from human faeces. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 14T belonged to the family Ruminococcaceae, but was located separately from known clostridial clusters within the taxon. The closest cultured relative of strain 14T was Acetivibrio cellulolyticus (89.7% sequence similarity). Strain 14T shared ~99% sequence similarity with cloned 16S rRNA gene sequences from uncultured bacteria derived from the human gut. Cells were Gram-stain-positive, non-motile cocci approximately 0.6μm in diameter. Strain 14T fermented pectins from citrus peel, apple, and kiwifruit as well as carbohydrates that are constituents of pectins and hemicellulose, such as galacturonic acid, xylose, and arabinose. TEM images of strain 14T, cultured in association with plant tissues, suggested extracellular fibrolytic activity associated with the bacterial cells, forming zones of degradation in the pectin-rich regions of middle lamella. Phylogenetic and phenotypic analysis supported the differentiation of strain 14T as a novel genus in the family Ruminococcaceae. The name Monoglobus pectinilyticus gen. nov., sp. nov. is proposed; the type strain is 14T (JCM 31914T=DSM 104782T).


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.


2005 ◽  
Vol 71 (10) ◽  
pp. 6308-6318 ◽  
Author(s):  
Helen A. Vrionis ◽  
Robert T. Anderson ◽  
Irene Ortiz-Bernad ◽  
Kathleen R. O'Neill ◽  
Charles T. Resch ◽  
...  

ABSTRACT The geochemistry and microbiology of a uranium-contaminated subsurface environment that had undergone two seasons of acetate addition to stimulate microbial U(VI) reduction was examined. There were distinct horizontal and vertical geochemical gradients that could be attributed in large part to the manner in which acetate was distributed in the aquifer, with more reduction of Fe(III) and sulfate occurring at greater depths and closer to the point of acetate injection. Clone libraries of 16S rRNA genes derived from sediments and groundwater indicated an enrichment of sulfate-reducing bacteria in the order Desulfobacterales in sediment and groundwater samples. These samples were collected nearest the injection gallery where microbially reducible Fe(III) oxides were highly depleted, groundwater sulfate concentrations were low, and increases in acid volatile sulfide were observed in the sediment. Further down-gradient, metal-reducing conditions were present as indicated by intermediate Fe(II)/Fe(total) ratios, lower acid volatile sulfide values, and increased abundance of 16S rRNA gene sequences belonging to the dissimilatory Fe(III)- and U(VI)-reducing family Geobacteraceae. Maximal Fe(III) and U(VI) reduction correlated with maximal recovery of Geobacteraceae 16S rRNA gene sequences in both groundwater and sediment; however, the sites at which these maxima occurred were spatially separated within the aquifer. The substantial microbial and geochemical heterogeneity at this site demonstrates that attempts should be made to deliver acetate in a more uniform manner and that closely spaced sampling intervals, horizontally and vertically, in both sediment and groundwater are necessary in order to obtain a more in-depth understanding of microbial processes and the relative contribution of attached and planktonic populations to in situ uranium bioremediation.


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