scholarly journals Genetic Diversity and Evolution of Bradyrhizobium Populations Nodulating Erythrophleum fordii, an Evergreen Tree Indigenous to the Southern Subtropical Region of China

2014 ◽  
Vol 80 (19) ◽  
pp. 6184-6194 ◽  
Author(s):  
Yao Yao ◽  
Rui Wang ◽  
Jun Kun Lu ◽  
Xin Hua Sui ◽  
En Tao Wang ◽  
...  
Keyword(s):  
Phylogenetic Trees ◽  
Root Nodules ◽  
Rflp Analysis ◽  
Divergent Evolution ◽  
Evolutionary Analysis ◽  
Subtropical Region ◽  
Content Type ◽  
Evergreen Tree ◽  
Intergenic Sequences ◽  
Erythrophleum Fordii

ABSTRACTThe nodulation ofErythrophleum fordiihas been recorded recently, but its microsymbionts have never been studied. To investigate the diversity and biogeography of rhizobia associated with this leguminous evergreen tree, root nodules were collected from the southern subtropical region of China. A total of 166 bacterial isolates were obtained from the nodules and characterized. In a PCR-based restriction fragment length polymorphism (RFLP) analysis of ribosomal intergenic sequences, the isolates were classified into 22 types within the genusBradyrhizobium. Sequence analysis of 16S rRNA, ribosomal intergenic spacer (IGS), and the housekeeping genesrecAandglnIIclassified the isolates into four groups: theBradyrhizobium elkaniiandBradyrhizobium pachyrhizigroups, comprising the dominant symbionts,Bradyrhizobium yuanmingense, and an unclassified group comprising the minor symbionts. ThenodCandnifHphylogenetic trees defined five or six lineages among the isolates, which was largely consistent with the definition of genomic species. The phylogenetic results and evolutionary analysis demonstrated that mutation and vertical transmission of genes were the principal processes for the divergent evolution ofBradyrhizobiumspecies associated withE. fordii, while lateral transfer and recombination of housekeeping and symbiotic genes were rare. The distribution of the dominant rhizobial populations was affected by soil pH and effective phosphorus. This is the first report to characterizeE. fordiirhizobia.

scholarly journals Classification and phylogeny of the cyanobiont Anabaena azollae Strasburger: an answered question?

2014 ◽  
Vol 64 (Pt_6) ◽  
pp. 1830-1840 ◽  
Author(s):  
Ana L. Pereira ◽  
Vitor Vasconcelos
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Phylogenetic Trees ◽  
Gene Sequence ◽  
Rflp Analysis ◽  
Future Research ◽  
Rrna Gene ◽  
Anabaena Azollae ◽  
Content Type ◽  
Link Type

The symbiosis Azolla–Anabaena azollae, with a worldwide distribution in pantropical and temperate regions, is one of the most studied, because of its potential application as a biofertilizer, especially in rice fields, but also as an animal food and in phytoremediation. The cyanobiont is a filamentous, heterocystic cyanobacterium that inhabits the foliar cavities of the pteridophyte and the indusium on the megasporocarp (female reproductive structure). The classification and phylogeny of the cyanobiont is very controversial: from its morphology, it has been named Nostoc azollae, Anabaena azollae, Anabaena variabilis status azollae and recently Trichormus azollae, but, from its 16S rRNA gene sequence, it has been assigned to Nostoc and/or Anabaena , and from its phycocyanin gene sequence, it has been assigned as non-Nostoc and non-Anabaena. The literature also points to a possible co-evolution between the cyanobiont and the Azolla host, since dendrograms and phylogenetic trees of fatty acids, short tandemly repeated repetitive (STRR) analysis and restriction fragment length polymorphism (RFLP) analysis of nif genes and the 16S rRNA gene give a two-cluster association that matches the two-section ranking of the host (Azolla). Another controversy surrounds the possible existence of more than one genus or more than one species strain. The use of freshly isolated or cultured cyanobionts is an additional problem, since their morphology and protein profiles are different. This review gives an overview of how morphological, chemical and genetic analyses influence the classification and phylogeny of the cyanobiont and future research.

scholarly journals Burkholderia sprentiae sp. nov., isolated from Lebeckia ambigua root nodules

2013 ◽  
Vol 63 (Pt_11) ◽  
pp. 3950-3957 ◽  
Author(s):  
Sofie E. De Meyer ◽  
Margo Cnockaert ◽  
Julie K. Ardley ◽  
Garth Maker ◽  
Ron Yates ◽  
...  
Keyword(s):  
Phylogenetic Trees ◽  
Sequence Similarity ◽  
Root Nodules ◽  
Distinct Group ◽  
Housekeeping Genes ◽  
Rrna Gene ◽  
Biochemical Tests ◽  
Phenotypic Differentiation ◽  
Content Type ◽  
Link Type

Seven Gram-stain-negative, rod-shaped bacteria were isolated from Lebeckia ambigua root nodules and authenticated on this host. Based on the 16S rRNA gene phylogeny, they were shown to belong to the genus Burkholderia , with the representative strain WSM5005T being most closely related to Burkholderia tuberum (98.08 % sequence similarity). Additionally, these strains formed a distinct group in phylogenetic trees based on the housekeeping genes gyrB and recA. Chemotaxonomic data including fatty acid profiles and analysis of respiratory quinones supported the assignment of the strains to the genus Burkholderia . Results of DNA–DNA hybridizations, and physiological and biochemical tests allowed genotypic and phenotypic differentiation of our strains from the closest species of the genus Burkholderia with a validly published name. Therefore, these strains represent a novel species for which the name Burkholderia sprentiae sp. nov. (type strain WSM5005T = LMG 27175T = HAMBI 3357T) is proposed.

Mesorhizobium shonense sp. nov., Mesorhizobium hawassense sp. nov. and Mesorhizobium abyssinicae sp. nov., isolated from root nodules of different agroforestry legume trees

2013 ◽  
Vol 63 (Pt_5) ◽  
pp. 1746-1753 ◽  
Author(s):  
Tulu Degefu ◽  
Endalkachew Wolde-meskel ◽  
Binbin Liu ◽  
Ilse Cleenwerck ◽  
Anne Willems ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Type Species ◽  
Phylogenetic Trees ◽  
Novel Species ◽  
Root Nodules ◽  
Housekeeping Genes ◽  
Content Type ◽  
Link Type ◽  
Wide Range ◽  
Type Strains

A total of 18 strains, representing members of the genus Mesorhizobium , obtained from root nodules of woody legumes growing in Ethiopia, have been previously shown, by multilocus sequence analysis (MLSA) of five housekeeping genes, to form three novel genospecies. In the present study, the phylogenetic relationship between representative strains of these three genospecies and the type strains of their closest phylogenetic neighbours Mesorhizobium plurifarium , Mesorhizobium amorphae , Mesorhizobium septentrionale and Mesorhizobium huakuii was further evaluated using a polyphasic taxonomic approach. In line with our earlier MLSA of other housekeeping genes, the phylogenetic trees derived from the atpD and glnII genes grouped the test strains into three well-supported, distinct lineages that exclude all defined species of the genus Mesorhizobium . The DNA–DNA relatedness between the representative strains of genospecies I–III and the type strains of their closest phylogenetic neighbours was low (≤59 %). They differed from each other and from their closest phylogenetic neighbours by the presence/absence of several fatty acids, or by large differences in the relative amounts of particular fatty acids. While showing distinctive features, they were generally able to utilize a wide range of substrates as sole carbon and nitrogen sources. The strains belonging to genospecies I, II and III therefore represent novel species for which we propose the names Mesorhizobium shonense sp. nov., Mesorhizobium hawassense sp. nov. and Mesorhizobium abyssinicae sp. nov. The isolates AC39aT ( = LMG 26966T = HAMBI 3295T), AC99bT ( = LMG 26968T = HAMBI 3301T) and AC98cT ( = LMG 26967T = HAMBI 3306T) are proposed as type strains for the respective novel species.

scholarly journals Burkholderia dilworthii sp. nov., isolated from Lebeckia ambigua root nodules

2014 ◽  
Vol 64 (Pt_4) ◽  
pp. 1090-1095 ◽  
Author(s):  
Sofie E. De Meyer ◽  
Margo Cnockaert ◽  
Julie K. Ardley ◽  
Ben-Erik Van Wyk ◽  
Peter A. Vandamme ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Phylogenetic Trees ◽  
Gene Sequence ◽  
Root Nodules ◽  
16S Rrna Gene Sequence ◽  
Rrna Gene ◽  
Rrna Gene Sequence ◽  
Content Type ◽  
Link Type

Three strains of Gram-stain-negative, rod-shaped bacteria were isolated from Lebeckia ambigua root nodules and authenticated on this host. Based on the 16S rRNA gene sequence phylogeny, they were shown to belong to the genus Burkholderia , with the representative strain WSM3556T being most closely related to Burkholderia caledonica LMG 23644T (98.70 % 16S rRNA gene sequence similarity) and Burkholderia rhynchosiae WSM3937T (98.50 %). Additionally, these strains formed a distinct group in phylogenetic trees of the housekeeping genes gyrB and recA. Chemotaxonomic data, including fatty acid profiles and analysis of respiratory quinones, supported the assignment of our strains to the genus Burkholderia . Results of DNA–DNA hybridizations, MALDI-TOF MS analysis and physiological and biochemical tests allowed genotypic and phenotypic differentiation of our strains from their nearest neighbour species. Therefore, these strains represent a novel species, for which the name Burkholderia dilworthii sp. nov. is proposed, with the type strain WSM3556T ( = LMG 27173T = HAMBI 3353T).

scholarly journals Amphritea ceti sp. nov., isolated from faeces of Beluga whale (Delphinapterus leucas)

2014 ◽  
Vol 64 (Pt_12) ◽  
pp. 4068-4072 ◽  
Author(s):  
Young-Ok Kim ◽  
Sooyeon Park ◽  
Doo Nam Kim ◽  
Bo-Hye Nam ◽  
Sung-Min Won ◽  
...  
Keyword(s):  
Phylogenetic Trees ◽  
Sequence Similarity ◽  
Beluga Whale ◽  
Delphinapterus Leucas ◽  
Rrna Gene ◽  
Phenotypic Properties ◽  
Content Type ◽  
Link Type ◽  
Beluga Whale Delphinapterus Leucas ◽  
Type Strains

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated and rod-shaped or ovoid bacterial strain, designated RA1T, was isolated from faeces collected from Beluga whale (Delphinapterus leucas) in Yeosu aquarium, South Korea. Strain RA1T grew optimally at 25 °C, at pH 7.0–8.0 and in the presence of 2.0 % (w/v) NaCl. Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences revealed that strain RA1T joins the cluster comprising the type strains of three species of the genus Amphritea , with which it exhibited 95.8–96.0 % sequence similarity. Sequence similarities to the type strains of other recognized species were less than 94.3 %. Strain RA1T contained Q-8 as the predominant ubiquinone and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C18 : 1ω7c and C16 : 0 as the major fatty acids. The major polar lipids of strain RA1T were phosphatidylethanolamine, phosphatidylglycerol, two unidentified lipids and one unidentified aminolipid. The DNA G+C content of strain RA1T was 47.4 mol%. The differential phenotypic properties, together with the phylogenetic distinctiveness, revealed that strain RA1T is separated from other species of the genus Amphritea . On the basis of the data presented, strain RA1T is considered to represent a novel species of the genus Amphritea , for which the name Amphritea ceti sp. nov. is proposed. The type strain is RA1T ( = KCTC 42154T = NBRC 110551T).

scholarly journals Pseudoseohaeicola caenipelagi gen. nov., sp. nov., isolated from a tidal flat

2015 ◽  
Vol 65 (Pt_6) ◽  
pp. 1819-1824 ◽  
Author(s):  
Sooyeon Park ◽  
Ji-Min Park ◽  
Chul-Hyung Kang ◽  
Song-Gun Kim ◽  
Jung-Hoon Yoon
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Tidal Flat ◽  
Type Strain ◽  
Type Species ◽  
Phylogenetic Trees ◽  
Sequence Similarity ◽  
Rrna Gene ◽  
Content Type ◽  
Link Type

A Gram-stain-negative, non-motile, aerobic and pleomorphic bacterium, designated BS-W13T, was isolated from a tidal flat on the South Sea, South Korea, and its taxonomic position was investigated using a polyphasic approach. Strain BS-W13T grew optimally at 25 °C, at pH 7.0–8.0 and in the presence of 1.0–2.0 % (w/v) NaCl. Neighbour-joining and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences showed that strain BS-W13T clustered with the type strain of Seohaeicola saemankumensis , showing the highest sequence similarity (95.96 %) to this strain. Strain BS-W13T exhibited 16S rRNA gene sequence similarity values of 95.95, 95.91, 95.72 and 95.68 % to the type strains of Sulfitobacter donghicola , Sulfitobacter porphyrae , Sulfitobacter mediterraneus and Roseobacter litoralis , respectively. Strain BS-W13T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The polar lipid profile of strain BS-W13T, containing phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminolipid and one unidentified lipid as major components, was distinguishable from those of some phylogenetically related taxa. The DNA G+C content of strain BS-W13T was 58.1 mol%. The phylogenetic data and differential chemotaxonomic and other phenotypic properties revealed that strain BS-W13T constitutes a novel genus and species within family Rhodobacteraceae of the class Alphaproteobacteria , for which the name Pseudoseohaeicola caenipelagi gen. nov., sp. nov. is proposed. The type strain is BS-W13T ( = KCTC 42349T = CECT 8724T).

scholarly journals A Novel Hydrolase Identified by Genomic-Proteomic Analysis of Phenylurea Herbicide Mineralization by Variovorax sp. Strain SRS16

2011 ◽  
Vol 77 (24) ◽  
pp. 8754-8764 ◽  
Author(s):  
Karolien Bers ◽  
Baptiste Leroy ◽  
Philip Breugelmans ◽  
Pieter Albers ◽  
Rob Lavigne ◽  
...  
Keyword(s):  
Proteomic Analysis ◽  
Krebs Cycle ◽  
Divergent Evolution ◽  
Phenylurea Herbicides ◽  
Transcription Analysis ◽  
Content Type ◽  
First Report ◽  
Phenylurea Herbicide ◽  
Hydrolyzing Enzymes ◽  
Krebs Cycle Intermediates

ABSTRACTThe soil bacterial isolateVariovoraxsp. strain SRS16 mineralizes the phenylurea herbicide linuron. The proposed pathway initiates with hydrolysis of linuron to 3,4-dichloroaniline (DCA) andN,O-dimethylhydroxylamine, followed by conversion of DCA to Krebs cycle intermediates. Differential proteomic analysis showed a linuron-dependent upregulation of several enzymes that fit into this pathway, including an amidase (LibA), a multicomponent chloroaniline dioxygenase, and enzymes associated with a modified chlorocatecholortho-cleavage pathway. Purified LibA is a monomeric linuron hydrolase of ∼55 kDa with aKmand aVmaxfor linuron of 5.8 μM and 0.16 nmol min−1, respectively. This novel member of the amidase signature family is unrelated to phenylurea-hydrolyzing enzymes from Gram-positive bacteria and lacks activity toward other tested phenylurea herbicides. Orthologues oflibAare present in all other tested linuron-degradingVariovoraxstrains with the exception ofVariovoraxstrains WDL1 and PBS-H4, suggesting divergent evolution of the linuron catabolic pathway in differentVariovoraxstrains. The organization of the linuron degradation genes identified in the draft SRS16 genome sequence indicates that gene patchwork assembly is at the origin of the pathway. Transcription analysis suggests that a catabolic intermediate, rather than linuron itself, acts as effector in activation of the pathway. Our study provides the first report on the genetic organization of a bacterial pathway for complete mineralization of a phenylurea herbicide and the first report on a linuron hydrolase in Gram-negative bacteria.

scholarly journals Belliella aquatica sp. nov., isolated from a saline lake

2015 ◽  
Vol 65 (Pt_5) ◽  
pp. 1622-1627 ◽  
Author(s):  
Zhi-Ping Zhong ◽  
Ying Liu ◽  
Ting-Ting Hou ◽  
Yu-Guang Zhou ◽  
Hong-Can Liu ◽  
...  
Keyword(s):  
Type Species ◽  
Phylogenetic Trees ◽  
Saline Lake ◽  
Qaidam Basin ◽  
Sequence Similarity ◽  
Rrna Gene ◽  
Respiratory Quinone ◽  
Content Type ◽  
Link Type ◽  
Gram Staining

A Gram-staining-negative bacterium, strain TS-T86T, was isolated from Lake Tuosu, a saline lake (salinity 5.4 %, w/w) in Qaidam basin, China. Its taxonomic position was determined by using a polyphasic approach. Strain TS-T86T was strictly heterotrophic, aerobic and catalase- and oxidase-positive. Cells were non-spore-forming, non-motile rods, 0.4–0.6 µm wide and 1.2–2.3 µm long. Growth was observed in the presence of 0–9.0 % (w/v) NaCl (optimum, 2.0 %), at 4–35 °C (optimum, 25 °C) and at pH 7.0–10.5 (optimum, pH 8.5–9.0). Strain TS-T86T contained MK-7 as the predominant respiratory quinone. The major fatty acids (>10 %) were iso-C15 : 1 G, iso-C15 : 0, iso-C17 : 1ω9c, iso-C17 : 0 3-OH and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The polar lipids consisted of phosphatidylethanolamine, an unknown phospholipid, six unidentified aminolipids and two uncharacterized lipids. The DNA G+C content was 35 mol% (T m). Phylogenetic trees based on 16S rRNA gene sequences showed that strain TS-T86T was associated with the genus Belliella , and showed the highest sequence similarity to Belliella baltica BA134T (98.5 %) and then to Belliella kenyensis No.164T (95.7 %) and Belliella pelovolcani CC-SAL-25T (95.3 %). DNA–DNA relatedness of strain TS-T86T to Belliella baltica DSM 15883T was 32±3 %. It is concluded that strain TS-T86T represents a novel species of the genus Belliella , for which the name Belliella aquatica sp. nov. is proposed. The type strain is TS-T86T ( = CGMCC 1.12479T = JCM 19468T).

scholarly journals Characterization of Epidemic IncI1-Iγ Plasmids Harboring Ambler Class A and C Genes in Escherichia coli and Salmonella enterica from Animals and Humans

2015 ◽  
Vol 59 (9) ◽  
pp. 5357-5365 ◽  
Author(s):  
Hilde Smith ◽  
Alex Bossers ◽  
Frank Harders ◽  
Guanghui Wu ◽  
Neil Woodford ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Salmonella Enterica ◽  
Phylogenetic Trees ◽  
Functional Study ◽  
Content Type ◽  
Gene Associations ◽  
Genes Encoding ◽  
Marked Resistance

ABSTRACTThe aim of the study was to identify the plasmid-encoded factors contributing to the emergence and spread of epidemic IncI1-Iγ plasmids obtained fromEscherichia coliandSalmonella entericaisolates from animal and human reservoirs. For this, 251 IncI1-Iγ plasmids carrying various extended-spectrum β-lactamase (ESBL) or AmpC β-lactamase genes were compared using plasmid multilocus sequence typing (pMLST). Thirty-two of these plasmids belonging to different pMLST types were sequenced using Roche 454 and Illumina platforms. Epidemic IncI1-Iγ plasmids could be assigned to various dominant clades, whereas rarely detected plasmids clustered together as a distinct clade. Similar phylogenetic trees were obtained using only the plasmid backbone sequences, showing that the differences observed between the plasmids belonging to distinct clades resulted mainly from differences between their backbone sequences. Plasmids belonging to the various clades differed particularly in the presence/absence of genes encoding partitioning and addiction systems, which contribute to stable inheritance during cell division and plasmid maintenance. Despite this, plasmids belonging to the various phylogenetic clades also showed marked resistance gene associations, indicating the circulation of successful plasmid-gene combinations. The variation intraYandexcAgenes found in IncI1-Iγ plasmids is conserved within pMLST sequence types and plays a role in incompatibility, although functional study is needed to elucidate the role of these genes in plasmid epidemiology.

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