scholarly journals Genetic Diversity, Symbiotic Evolution, and Proposed Infection Process of Bradyrhizobium Strains Isolated from Root Nodules of Aeschynomene americana L. in Thailand

2012 ◽  
Vol 78 (17) ◽  
pp. 6236-6250 ◽  
Author(s):  
Rujirek Noisangiam ◽  
Kamonluck Teamtisong ◽  
Panlada Tittabutr ◽  
Nantakorn Boonkerd ◽  
Uchiumi Toshiki ◽  
...  

ABSTRACTThe diversity of bacteria nodulatingAeschynomene americanaL. in Thailand was determined from phenotypic characteristics and multilocus sequence analysis of the 16S rRNA gene and 3 housekeeping genes (dnaK,recA, andglnB). The isolated strains were nonphotosynthetic bacteria and were assigned to the genusBradyrhizobium, in whichB. yuanmingensewas the dominant species. Some of the other species, includingB. japonicum,B. liaoningense, andB. canariense, were minor species. These isolated strains were divided into 2 groups—nod-containing and divergentnod-containing strains—based on Southern blot hybridization and PCR amplification ofnodABCgenes. The divergentnodgenes could not be PCR amplified and failed to hybridizenodgene probes designed fromB. japonicumUSDA110, but hybridized to probes from other bradyrhizobial strains under low-stringency conditions. The grouping based on sequence similarity ofnodgenes was well correlated with the grouping based on that ofnifHgene, in which thenod-containing and divergentnod-containing strains were obviously distinguished. The divergentnod-containing strains and photosynthetic bradyrhizobia shared closenifHsequence similarity and an ability to fix nitrogen in the free-living state. Surprisingly, the strains isolated fromA. americanacould nodulateAeschynomeneplants that belong to different cross-inoculation (CI) groups, includingA. afrasperaandA. indica. This is the first discovery of bradyrhizobia (nonphotosynthetic andnod-containing strain) originating from CI group 1 nodulating roots ofA. indica(CI group 3). An infection process used to establish symbiosis onAeschynomenedifferent from the classical one is proposed.

2013 ◽  
Vol 63 (Pt_11) ◽  
pp. 3950-3957 ◽  
Author(s):  
Sofie E. De Meyer ◽  
Margo Cnockaert ◽  
Julie K. Ardley ◽  
Garth Maker ◽  
Ron Yates ◽  
...  

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.


2013 ◽  
Vol 63 (Pt_11) ◽  
pp. 3944-3949 ◽  
Author(s):  
Sofie E. De Meyer ◽  
Margo Cnockaert ◽  
Julie K. Ardley ◽  
Robert D. Trengove ◽  
Giovanni Garau ◽  
...  

Two strains of Gram-stain-negative, rod-shaped bacteria were isolated from root nodules of the South African legume Rhynchosia ferulifolia and authenticated on this host. Based on phylogenetic analysis of the 16S rRNA gene, strains WSM3930 and WSM3937T belonged to the genus Burkholderia , with the highest degree of sequence similarity to Burkholderia terricola (98.84 %). Additionally, the housekeeping genes gyrB and recA were analysed since 16S rRNA gene sequences are highly similar between closely related species of the genus Burkholderia . The results obtained for both housekeeping genes, gyrB and recA, showed the highest degree of sequence similarity of the novel strains towards Burkholderia caledonica LMG 19076T (94.2 % and 94.5 %, respectively). Chemotaxonomic data, including fatty acid profiles and respiratory quinone data supported the assignment of strains WSM3930 and WSM3937T to the genus Burkholderia . DNA–DNA hybridizations, and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strains WSM3930 and WSM3937T from the most closely related species of the genus Burkholderia with validly published names. We conclude, therefore, that these strains represent a novel species for which the name Burkholderia rhynchosiae sp. nov. is proposed, with strain WSM3937T ( = LMG 27174T = HAMBI 3354T) as the type strain.


2013 ◽  
Vol 63 (Pt_10) ◽  
pp. 3823-3828 ◽  
Author(s):  
Chokchai Kittiwongwattana ◽  
Chitti Thawai

A Gram-stain-negative, rod-shaped bacterium was isolated and designated strain L6-8T during a study of endophytic bacterial communities in lesser duckweed (Lemna aequinoctialis). Cells of strain L6-8T were motile with peritrichous flagella. The analysis of the nearly complete 16S rRNA gene sequence indicated that strain L6-8T was phylogenetically related to species of the genus Rhizobium . Its closest relatives were Rhizobium borbori DN316T (97.6 %), Rhizobium oryzae Alt 505T (97.3 %) and Rhizobium pseudoryzae J3-A127T (97.0 %). The sequence similarity analysis of housekeeping genes recA, glnII, atpD and gyrB showed low levels of sequence similarity (<91.5 %) between strain L6-8T and other species of the genus Rhizobium with validly published names. The pH range for growth was 4.0–9.0 (optimum 6.0–7.0), and the temperature range for growth was 20–45 °C (optimum 30 °C). Strain L6-8T tolerated NaCl up to 2 % (w/v) (optimum 1 % NaCl). The predominant components of cellular fatty acids were C19 : 0 cyclo ω8c (31.32 %), summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c; 25.39 %) and C16 : 0 (12.03 %). The DNA G+C content of strain L6-8T was 60.4 mol% (T m). nodC and nifH were not amplified in strain L6-8T. DNA–DNA relatedness between strain L6-8T and R. borbori DN316T, R. oryzae Alt505T and R. pseudoryzae J3-A127T was between 11.2 and 18.3 %. Based on the sequence similarity analyses, phenotypic, biochemical and physiological characteristics and DNA–DNA hybridization, strain L6-8T could be readily distinguished from its closest relatives and represents a novel species of the genus Rhizobium , for which the name Rhizobium paknamense sp. nov. is proposed. The type strain is L6-8T ( = NBRC 109338T = BCC 55142T).


2015 ◽  
Vol 65 (Pt_2) ◽  
pp. 510-515 ◽  
Author(s):  
Abdolrazagh Hashemi Shahraki ◽  
Cengiz Çavuşoğlu ◽  
Emanuele Borroni ◽  
Parvin Heidarieh ◽  
Orhan Kaya Koksalan ◽  
...  

Six strains of a rapidly growing scotochromogenic mycobacterium were isolated from pulmonary specimens of independent patients. Biochemical and cultural tests were not suitable for their identification. The mycolic acid pattern analysed by HPLC was different from that of any other mycobacterium. Genotypic characterization, targeting seven housekeeping genes, revealed the presence of microheterogeneity in all of them. Different species were more closely related to the test strains in various regions: the type strain of Mycobacterium moriokaense showed 99.0 % 16S rRNA gene sequence similarity, and 91.5–96.5 % similarity for the remaining six regions. The whole genome sequences of the proposed type strain and that of M. moriokaense presented an average nucleotide identity (ANI) of 82.9 %. Phylogenetic analysis produced poorly robust trees in most genes with the exception of rpoB and sodA where Mycobacterium flavescens and Mycobacterium novocastrense were the closest species. This phylogenetic relatedness was confirmed by the tree inferred from five concatenated genes, which was very robust. The polyphasic characterization of the test strains, supported by the ANI value, demonstrates that they belong to a previously unreported species, for which the name Mycobacterium celeriflavum sp. nov. is proposed. The type strain is AFPC-000207T ( = DSM 46765T = JCM 18439T).


2014 ◽  
Vol 64 (Pt_4) ◽  
pp. 1373-1377 ◽  
Author(s):  
Xiao-Xia Zhang ◽  
Xue Tang ◽  
Rizwan Ali Sheirdil ◽  
Lei Sun ◽  
Xiao-Tong Ma

Two strains (J3-AN59T and J3-N84) of Gram-stain-negative, aerobic and rod-shaped bacteria were isolated from the roots of fresh rice plants. The 16S rRNA gene sequence similarity results showed that the similarity between strains J3-AN59T and J3-N84 was 100 %. Both strains were phylogenetically related to members of the genus Rhizobium , and they were most closely related to Rhizobium tarimense ACCC 06128T (97.43 %). Similarities in the sequences of housekeeping genes between strains J3-AN59T and J3-N84 and those of recognized species of the genus Rhizobium were less than 90 %. The polar lipid profiles of both strains were predominantly composed of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and an unknown aminophospholipid. The major cellular fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C16 : 0. The DNA G+C contents of J3-AN59T and J3-N84 were 55.7 and 57.1 mol%, respectively. The DNA–DNA relatedness value between J3-AN59T and J3-N84 was 89 %, and strain J3-AN59T showed 9 % DNA–DNA relatedness to R. tarimense ACCC 06128T, the most closely related strain. Based on this evidence, we found that J3-AN59T and J3-N84 represent a novel species in the genus Rhizobium and we propose the name Rhizobium rhizoryzae sp. nov. The type strain is J3-AN59T ( = ACCC 05916T = KCTC 23652T).


2014 ◽  
Vol 64 (Pt_6) ◽  
pp. 2060-2065 ◽  
Author(s):  
Wei-Chun Hung ◽  
Hsiao-Jan Chen ◽  
Jui-Chang Tsai ◽  
Sung-Pin Tseng ◽  
Tai-Fen Lee ◽  
...  

Four Gram-staining-positive, catalase-negative, coccoid isolates, designated NTUH_1465T, NTUH_2196, NTUH_4957 and NTUH_5572T, were isolated from human specimens. The four isolates displayed more than 99.6 % 16S rRNA gene sequence similarity with Gemella haemolysans ATCC 10379T, and 96.7 to 98.6 % similarity with Gemella sanguinis ATCC 700632T, Gemella morbillorum ATCC 27824T or Gemella cuniculi CCUG 42726T. However, phylogenetic analysis of concatenated sequences of three housekeeping genes, groEL, rpoB and recA, suggested that the four isolates were distinct from G. haemolysans ATCC 10379T and other species. Isolates NTUH_2196, NTUH_4957 and NTUH_5572T clustered together and formed a stable monophyletic clade. DNA–DNA hybridization values among strains NTUH_1465T and NTUH_5572T and their phylogenetically related neighbours were all lower than 49 %. The four isolates could be distinguished from G. haemolysans and other species by phenotypic characteristics. Based on the phylogenetic and phenotypic results, two novel species Gemella parahaemolysans sp. nov. (type strain NTUH_1465T = BCRC 80365T = JCM 18067T) and Gemella taiwanensis sp. nov. (type strain NTUH_5572T = BCRC 80366T = JCM 18066T) are proposed.


2015 ◽  
Vol 65 (Pt_2) ◽  
pp. 412-417 ◽  
Author(s):  
Wei Chen ◽  
Xia-Fang Sheng ◽  
Lin-Yan He ◽  
Zhi Huang

A Gram-stain-negative, rod-shaped bacterial strain, H66T, was isolated from the surfaces of weathered rock (purple siltstone) found in Yanting, Sichuan Province, PR China. Cells of strain H66T were motile with peritrichous flagella. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain H66T belongs to the genus Rhizobium . It is closely related to Rhizobium huautlense SO2T (98.1 %), Rhizobium alkalisoli CCBAU 01393T (98.0 %) and Rhizobium cellulosilyticum ALA10B2T (98.0 %). Analysis of the housekeeping genes, recA, glnII and atpD, showed low levels of sequence similarity (<92.0 %) between strain H66T and other recognized species of the genus Rhizobium . The predominant components of the cellular fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C16 : 0. The G+C content of strain H66T was 60.3 mol%. Strain H66T is suggested to be a novel species of the genus Rhizobium based on the low levels of DNA–DNA relatedness (ranging from 14.3 % to 40.0 %) with type strains of species of the genus Rhizobium and on its unique phenotypic characteristics. The namehttp://dx.doi.org/10.1601/nm.1279 Rhizobium yantingense sp. nov. is proposed for this novel species. The type strain is H66T ( = CCTCC AB 2014007T = LMG 28229T).


2014 ◽  
Vol 64 (Pt_1) ◽  
pp. 146-151 ◽  
Author(s):  
Yi-sheng Chen ◽  
Misa Otoguro ◽  
Yu-hsuan Lin ◽  
Shwu-fen Pan ◽  
Si-hua Ji ◽  
...  

A coccal-shaped organism, designated 516T, was isolated from yan-tsai-shin (fermented broccoli stems), a traditional fermented food in Taiwan. 16S rRNA gene sequencing results showed that strain 516T had 98.9 % sequence similarity to that of the type strain Lactococcus garvieae NBRC 100934T. Comparison of three housekeeping genes, rpoA, rpoB and pheS, revealed that strain 516T was well separated from Lactococcus garvieae NBRC 100934T. DNA–DNA hybridization studies indicated that strain 516T had low DNA relatedness with Lactococcus garvieae NBRC 100934T (46.1 %). The DNA G+C content of strain 516T was 38.1 mol% and the major fatty acids were C16 : 0 (22.7 %), C19 : 0 cyclo ω8c (17.9 %) and summed feature 7 (29.0 %). Based on the evidence, strain 516T represents a novel species of the genus Lactococcus , for which the name Lactococcus formosensis sp. nov. is proposed. The type strain is 516T ( = NBRC 109475T = BCRC 80576T).


2013 ◽  
Vol 63 (Pt_7) ◽  
pp. 2424-2429 ◽  
Author(s):  
Maripat Turdahon ◽  
Ghenijan Osman ◽  
Maryam Hamdun ◽  
Khayir Yusuf ◽  
Zumret Abdurehim ◽  
...  

A Gram-negative, non-motile, pale-yellow, rod-shaped bacterial strain, PL-41T, was isolated from Populus euphratica forest soil at the ancient Khiyik River valley in Xinjiang Uyghur Autonomous Region, People's Republic of China. Strain PL-41T grew optimally at 30 °C and pH 7.0–8.0. The major quinone was Q-10. The predominant cellular fatty acids of strain PL-41T were summed feature 8 (comprising C18 : 1ω7c and C18 : 1ω6c), C16 : 0 and C19 : 0 cyclo ω8c. Polar lipids of strain PL-41T include two unidentified aminophospholipids (APL1, 2), two unidentified phospholipids (PL1, 2), phosphatidylcholine and three unidentified lipids (L1–3). Strain PL-41T showed 16S rRNA gene sequence similarity of 97.0–97.5 % to the type strains of recognized species of the genus Rhizobium . Phylogenetic analysis of strain PL-41T based on the sequences of housekeeping genes recA and atpD confirmed (similarities are less than 90 %) its position as a distinct species of the genus Rhizobium . The DNA G+C content was 57.8 mol%. DNA–DNA relatedness between strain PL-41T and the type strains of Rhizobium huautlense S02T, Rhizobium alkalisoli CCBAU 01393T, Rhizobium vignae CCBAU 05176T and Rhizobium loessense CCBAU 7190BT were 33.4, 22.6, 25.5 and 45.1 %, respectively, indicating that strain PL-41T was distinct from them genetically. Strain PL-41T also can be differentiated from these four phylogenetically related species of the genus Rhizobium by various phenotypic properties. On the basis of phenotypic properties, phylogenetic distinctiveness and genetic data, strain PL-41T is considered to represent a novel species of the genus Rhizobium , for which the name Rhizobium tarimense sp. nov. is proposed. The type strain is PL-41T ( = CCTCC AB 2011011T = NRRL B-59556T).


2013 ◽  
Vol 63 (Pt_6) ◽  
pp. 2309-2313 ◽  
Author(s):  
Tímea Tóth ◽  
Tamás Lakatos ◽  
András Koltay

Seven Gram-negative bacterial strains were isolated from oozing bark canker of poplar (Populus×euramericana) trees in Hungary. They showed high (>98.3 %) 16S rRNA gene sequence similarity to Lonsdalea quercina ; however, they differed from this species in several phenotypic characteristics. Multilocus sequence analysis based on three housekeeping genes (gyrB, atpD and infB) revealed, and DNA–DNA hybridization analysis confirmed, that this group of bacterial strains forms a distinct lineage within the species Lonsdalea quercina . A detailed study of phenotypic and physiological characteristics confirmed the separation of isolates from poplars from other subspecies of L. quercina ; therefore, a novel subspecies, Lonsdalea quercina subsp. populi, type strain NY060T ( = DSM 25466T = NCAIM B 02483T), is proposed.


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