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Wen Xin Chen - One of the best experts on this subject based on the ideXlab platform.
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evolutionarily conserved node nodo t1ss and hydrogenase system in rhizobia of astragalus membranaceus and caragana intermedia
Frontiers in Microbiology, 2017Co-Authors: Wen Xin Chen, En Tao Wang, Chang Fu Tian, Hui Yan, Jian Bo Xie, Na Yuan, Liang Zhong, Wen-feng ChenAbstract:Mesorhizobium species are the main microsymbionts associated with the medicinal or sand-fixation plants Astragalus membranaceus and Caragana intermedia (AC) in temperate regions of China, while all the Mesorhizobium strains isolated from each of these plants could nodulate both of them. However, Rhizobium yanglingense strain CCBAU01603 could nodulate AC plants and it's a high efficiency symbiotic and competitive strain with Caragana. Therefore, the common features shared by these symbiotic rhizobia in genera of Mesorhizobium and Rhizobium still remained undiscovered. In order to study the genomic background influencing the host preference of these AC symbiotic strains, the whole genomes of two (M. silamurunense CCBAU01550, M. silamurunense CCBAU45272) and five representative strains (M. septentrionale CCBAU01583, M. amorphae CCBAU01570, M. caraganae CCBAU01502, M. temperatum CCBAU01399, and R. yanglingense CCBAU01603) originally isolated from AC plants were sequenced, respectively. As results, type III secretion systems (T3SS) of AC rhizobia evolved in an irregular pattern, while an evolutionarily specific region including nodE, nodO, T1SS, and a hydrogenase system was detected to be conserved in all these AC rhizobia. Moreover, nodO was verified to be prevalently distributed in other AC rhizobia and was presumed as a factor affecting the nodule formation process. In conclusion, this research interpreted the multifactorial features of the AC rhizobia that may be associated with their host specificity at cross-nodulation group, including nodE, nodZ, T1SS as the possible main determinants; and nodO, hydrogenase system, and T3SS as factors regulating the bacteroid formation or nitrogen fixation efficiency.
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genotypic alteration and competitive nodulation of Mesorhizobium muleiense against exotic chickpea rhizobia in alkaline soils
Systematic and Applied Microbiology, 2014Co-Authors: Jun Jie Zhang, Wen-feng Chen, En Tao Wang, Tao Yu, Wen Xin ChenAbstract:Abstract Mesorhizobium muleiense , Mesorhizobium mediterraneum and Mesorhizobium ciceri are chickpea ( Cicer arietinum L.) rhizobia that share a high similarity of the symbiotic genes nodC and nifH , but they have different geographic distributions. M. muleiense has been isolated and found only in alkaline soils of Xinjiang, China, whereas the other two strains have been found in the Mediterranean and India. To investigate the species stability of M. muleiense during natural evolution and its capability of competitive nodulation against the other two exotic species, re-sampling of nodules in the field and competition experiments between the three species were conducted. The results showed that the predominant microsymbiont associated with chickpea grown in Xinjiang was still M. muleiense , but the predominant genotypes of M. muleiense had changed significantly during the four years since a previous survey. The data also showed that M. mediterraneum and M. ciceri were more competitive than the residential strain of M. muleiense CCBAU 83963 T in sterilized vermiculite or soils from Xinjiang. However, in non-sterilized soils, M. muleiense was the predominant nodule occupier. These results indicated that natural or adapting evolution of M. muleiense was occurring in fields subjected to changing environmental factors. In addition, the biogeography and symbiotic associations of rhizobia with their host legumes were also influenced by biological factors in the soil, such as indigenous rhizobia and other organisms.
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Mesorhizobium qingshengii sp nov isolated from effective nodules of astragalus sinicus
International Journal of Systematic and Evolutionary Microbiology, 2013Co-Authors: Wen Tao Zheng, En Tao Wang, Jun Jie Zhang, Xiao Xia Zhang, Rui Wang, Ying Li, Wen Xin ChenAbstract:In a study on the diversity of rhizobia isolated from root nodules of Astragalus sinicus, five strains showed identical 16S rRNA gene sequences. They were related most closely to the type strains of Mesorhizobium loti , Mesorhizobium shangrilense , Mesorhizobium ciceri and Mesorhizobium australicum , with sequence similarities of 99.6–99.8 %. A polyphasic approach, including 16S–23S intergenic spacer (IGS) RFLP, comparative sequence analysis of 16S rRNA, atpD, glnII and recA genes, DNA–DNA hybridization and phenotypic tests, clustered the five isolates into a coherent group distinct from all recognized Mesorhizobium species. Except for strain CCBAU 33446, from which no symbiotic gene was detected, the four remaining strains shared identical nifH and nodC gene sequences and nodulated with Astragalus sinicus. In addition, these five strains showed similar but different fingerprints in IGS-RFLP and BOX-repeat-based PCR, indicating that they were not clones of the same strain. They were also distinguished from recognized Mesorhizobium species by several phenotypic features and fatty acid profiles. Based upon all the results, we suggest that the five strains represent a novel species for which the name Mesorhizobium qingshengii sp. nov. is proposed. The type strain is CCBAU 33460T ( = CGMCC 1.12097T = LMG 26793T = HAMBI 3277T). The DNA G+C content of the type strain is 59.52 mol% (T m).
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Mesorhizobium muleiense sp nov nodulating with cicer arietinum l
International Journal of Systematic and Evolutionary Microbiology, 2012Co-Authors: Jun Jie Zhang, En Tao Wang, Wen-feng Chen, Xiao Xia Zhang, Yan Li, Wen Xin ChenAbstract:Three chickpea rhizobial strains (CCBAU 83963T, CCBAU 83939 and CCBAU 83908), which were identified previously as representing a distinctive genospecies, were further studied here and compared taxonomically with related species in the genus Mesorhizobium . Results from SDS-PAGE of whole-cell soluble proteins revealed differences from closely related recognized species of the genus Mesorhizobium . Levels of DNA–DNA relatedness were 15.28–50.97 % between strain CCBAU 83963T and the type strains of recognized Mesorhizobium species (except for Mesorhizobium thiogangeticum ). Strain CCBAU 83963T contained fatty acids characteristic of members of the genus Mesorhizobium , but it possessed high concentrations of C19 : 0 cyclo ω8c and iso-C17 : 0. Strain CCBAU 83963T had phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol as major polar lipids, and an ornithine-containing lipid, phosphatidyl-N-dimethylethanolamine and cardiolipin as minor components. Nodulation tests demonstrated the distinct symbiotic character of strain CCBAU 83963T; only Cicer arietinum, its host plant, could be invaded to form effective nitrogen-fixing nodules. The narrow spectrum of utilization of sole carbon sources, lower resistance to antibiotics, and NaCl, pH and temperature growth ranges differentiated these novel rhizobia from recognized species of the genus Mesorhizobium . Based on the data presented, the three novel rhizobial strains are considered to represent a novel species of the genus Mesorhizobium , for which the name Mesorhizobium muleiense sp. nov. is proposed. The type strain is CCBAU 83963T ( = HAMBI 3264T = CGMCC 1.11022T).
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Mesorhizobium silamurunense sp nov isolated from root nodules of astragalus species
International Journal of Systematic and Evolutionary Microbiology, 2012Co-Authors: Chun Tian Zhao, Wen Xin Chen, En Tao Wang, Wen-feng Chen, Yan Ming Zhang, Xiao Xia ZhangAbstract:Four rhizobial strains representing a previously defined novel group in the genus Mesorhizobium and isolated from Astragalus species in China were further characterized using a polyphasic approach. Phylogenetic analysis of 16S rRNA gene sequences showed that these Gram-negative bacteria belonged to the genus Mesorhizobium , with Mesorhizobium plurifarium LMG 11892T as the closest neighbour sharing a sequence similarity of 99.8 %. Comparative sequence analysis of the atpD, recA, glnII, rpoB, nodC and nifH genes, SDS-PAGE of whole-cell soluble proteins, DNA–DNA hybridization, fatty acid profiles and a series of phenotypic and physiological tests differentitated the novel group from all recognized species of the genus Mesorhizobium . Based on the data obtained in the present and previous studies, this group represents a novel species within the genus Mesorhizobium , for which the name Mesorhizobium silamurunense sp. nov. is proposed. The type strain is CCBAU 01550T ( = HAMBI 3029T = LMG 24822T), and could form effective nodules on Astragalus membranaceus, Astragalus adsurgens and Caragana intermedia, and ineffective nodules on Phaseolus vulgaris in cross-nodulation tests.
Peter J W Young - One of the best experts on this subject based on the ideXlab platform.
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multilocus sequence analysis reveals multiple symbiovars within Mesorhizobium species
Systematic and Applied Microbiology, 2012Co-Authors: Marta Laranjo, Peter J W Young, Solange OliveiraAbstract:The genus Mesorhizobium includes species nodulating several legumes, such as chickpea, which has a high agronomic importance. Chickpea rhizobia were originally described as either Mesorhizobium ciceri or M. mediterraneum. However, rhizobia able to nodulate chickpea have been shown to belong to several different species within the genus Mesorhizobium. The present study used a multilocus sequence analysis approach to infer a high resolution phylogeny of the genus Mesorhizobium and to confirm the existence of a new chickpea nodulating genospecies. The phylogenetic structure of the Mesorhizobium clade was evaluated by sequence analysis of the 16S rRNA gene, ITS region and the five core genes atpD, dnaJ, glnA, gyrB, and recA. Phylogenies obtained with the different genes are in overall good agreement and a well-supported, almost fully resolved, phylogenetic tree was obtained using the combined data. Our phylogenetic analyses of core genes sequences and their comparison with the symbiosis gene nodC, corroborate the existence of one new chickpea Mesorhizobium genospecies and one new symbiovar, M. opportunistum sv. ciceri. Furthermore, our results show that symbiovar ciceri spreads over six species of mesorhizobia. To our knowledge this study shows the most complete Mesorhizobium multilocus phylogeny to date and contributes to the understanding of how a symbiovar may be present in different species.
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Mesorhizobium camelthorni sp nov isolated from alhagi sparsifolia
International Journal of Systematic and Evolutionary Microbiology, 2011Co-Authors: Weimin Chen, Cyril Bontemps, Peter J W YoungAbstract:Nine strains isolated from symbiotic root nodules on Alhagi sparsifolia were previously designated as representing genospecies I. Phylogenetic analyses indicated that genospecies I was related closely to Mesorhizobium alhagi (genospecies II), and clearly formed a new lineage within the genus Mesorhizobium. In this study, we differentiated genospecies I from recognized species of the genus Mesorhizobium based on phylogenetic analyses of additional core genes (recA, glnA), levels of DNA–DNA relatedness (,43.3%), fatty acid profile (58% C18:1v7c, 19% 11-methyl C18:1v7c), and biochemical and physiological characteristics. The nine strains are therefore considered to represent a novel species of the genus Mesorhizobium, for which the name Mesorhizobium camelthorni sp. nov. is proposed. The type strain is CCNWXJ 40-4 T (5HAMBI 3020 T 5ACCC 14549 T ).
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Mesorhizobium alhagi sp nov isolated from wild alhagi sparsifolia in north western china
International Journal of Systematic and Evolutionary Microbiology, 2010Co-Authors: Weimin Chen, Cyril Bontemps, Peter J W YoungAbstract:Eleven strains that formed symbiotic root nodules on Alhagi sparsifolia, designated previously as genospecies II, were identified as a new lineage of Mesorhizobium (Alphaproteobacteria) that could be differentiated from all previously recognized species of the genus Mesorhizobium by using 16S rRNA gene sequences (<97.8 % similarity), DNA–DNA hybridization (<45 %), dnaJ, dnaK, recA, glnA, nifH, nodA and nodC gene sequences, fatty acid profiles (C18 : 1 ω7c, 35 %;11-methyl C18 : 1 ω7c, 30 %) and numerical taxonomy. These strains are therefore considered to represent a novel species, for which the name Mesorhizobium alhagi sp. nov. is proposed, with isolate CCNWXJ12-2T (=ACCC 15461T=HAMBI 3019T) as the type strain.
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Mesorhizobium alhagi sp nov isolated from wild alhagi sparsifolia in north western china
International Journal of Systematic and Evolutionary Microbiology, 2010Co-Authors: Weimin Chen, Cyril Bontemps, Peter J W YoungAbstract:Eleven strains that formed symbiotic root nodules on Alhagi sparsifolia, designated previously as genospecies II, were identified as a new lineage of Mesorhizobium (Alphaproteobacteria) that could be differentiated from all previously recognized species of the genus Mesorhizobium by using 16S rRNA gene sequences (<97.8 % similarity), DNA–DNA hybridization (<45 %), dnaJ, dnaK, recA, glnA, nifH, nodA and nodC gene sequences, fatty acid profiles (C18 : 1 ω7c, 35 %;11-methyl C18 : 1 ω7c, 30 %) and numerical taxonomy. These strains are therefore considered to represent a novel species, for which the name Mesorhizobium alhagi sp. nov. is proposed, with isolate CCNWXJ12-2T (=ACCC 15461T=HAMBI 3019T) as the type strain.
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Mesorhizobium septentrionale sp nov and Mesorhizobium temperatum sp nov isolated from astragalus adsurgens growing in the northern regions of china
International Journal of Systematic and Evolutionary Microbiology, 2004Co-Authors: Sarah L Turner, Zewdu Terefework, Peter J W Young, En Tao Wang, Kristina Lindstrom, Jun Gu, Wen Xin ChenAbstract:Ninety-five rhizobial strains isolated from Astragalus adsurgens growing in the northern regions of China were classified into three main groups, candidate species I, II and III, based on a polyphasic approach. Comparative analysis of full-length 16S rRNA gene sequences of representative strains showed that candidate species I and II were Mesorhizobium, while candidate species III, which consisted of non-nodulating strains, was closely related to Agrobacterium tumefaciens. The phylogenetic relationships of the three candidate species and some related strains were also confirmed by the sequencing of glnA genes, which were used as an alternative chromosomal marker. The DNA-DNA relatedness was between 11?3 and 47?1% among representative strains of candidate species I and II and the type strains of defined Mesorhizobium species. Candidate III had DNA relatedness of between 4?3 and 25?2% with type strains of Agrobacterium tumefaciens and Agrobacterium rubi. Two novel species are proposed to accommodate candidate species I and II, Mesorhizobium septentrionale sp. nov. (type strain, SDW014 T =CCBAU 11014 T =HAMBI 2582 T ) and Mesorhizobium temperatum sp. nov. (type strain, SDW018 T =CCBAU 11018 T =HAMBI 2583 T ), respectively. At least two distinct nodA sequences were identified among the strains. The numerically dominant nodA sequence type was most similar to that from the Mesorhizobium tianshanense type strain and was identified in strains belonging to the two novel species as well as other, as yet, undefined genome types. Host range studies indicate that the different nodA sequences correlate with different host ranges. Further comparative studies with the defined Agrobacterium species are needed to clarify the taxonomic identity of candidate species III.
Encarna Velázquez - One of the best experts on this subject based on the ideXlab platform.
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plant growth promotion abilities of phylogenetically diverse Mesorhizobium strains effect in the root colonization and development of tomato seedlings
Microorganisms, 2020Co-Authors: Esther Menendez, Juan Perezyepez, Encarna Velázquez, Ana Rodriguezperez, Mercedes Hernandez, Milagros LeonbarriosAbstract:Mesorhizobium contains species widely known as nitrogen-fixing bacteria with legumes, but their ability to promote the growth of non-legumes has been poorly studied. Here, we analyzed the production of indole acetic acid (IAA), siderophores and the solubilization of phosphate and potassium in a collection of 24 strains belonging to different Mesorhizobium species. All these strains produce IAA, 46% solubilized potassium, 33% solubilize phosphate and 17% produce siderophores. The highest production of IAA was found in the strains Mesorhizobium ciceri CCANP14 and Mesorhizobium tamadayense CCANP122, which were also able to solubilize potassium. Moreover, the strain CCANP14 showed the maximum phosphate solubilization index, and the strain CCANP122 was able to produce siderophores. These two strains were able to produce cellulases and cellulose and to originate biofilms in abiotic surfaces and tomato root surface. Tomato seedlings responded positively to the inoculation with these two strains, showing significantly higher plant growth traits than uninoculated seedlings. This is the first report about the potential of different Mesorhizobium species to promote the growth of a vegetable. Considering their use as safe for humans, animals and plants, they are an environmentally friendly alternative to chemical fertilizers for non-legume crops in the framework of sustainable agriculture.
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Mesorhizobium helmanticense sp nov isolated from lotus corniculatus nodules
International Journal of Systematic and Evolutionary Microbiology, 2017Co-Authors: Marta Marcosgarcia, Martha Helena Ramirezbahena, Encarna Velázquez, Alvaro Peix, Esther Menendez, Pedro F Mateos, Raul RivasAbstract:In this study, three strains belonging to the genus Mesorhizobium , CSLC115NT, CSLC19N and CSLC37N, isolated from Lotus corniculatus nodules in Spain, were characterized. Their 16S rRNA gene sequences were closely related to those of Mesorhizobium metallidurans STM 2683T, Mesorhizobium tianshanense A-1BST, Mesorhizobium tarimense CCBAU 83306T, Mesorhizobium gobiense CCBAU 83330T and Mesorhizobium caraganae CCBAU 11299T with similarity values higher than 99.7 %. The analysis of concatenated recA and glnII genes showed that the most closely related type strains were M. metallidurans STM 2683T, M. tianshanense A-1BST and M. tarimense CCBAU 83306T with 96, 95 and 94 % similarity values in the recA gene and 95, 94 and 94 % in the glnII gene, respectively. M. metallidurans LMG 24485T, M. tianshanense USDA 3592T and M. tarimense LMG 24338T showed means of 44, 41 and 42 % DNA–DNA relatedness, respectively, with respect to strain CSLC115NT. The major fatty acids were those from summed feature 8 (C18 : 1ω7c/C18 : 1ω6c), C16 : 0 and C18 : 1ω7c 11-methyl. The results of phenotypic characterization support that the L. corniculatus nodulating strains analysed in this work belong to a novel species of the genus Mesorhizobium for which the name Mesorhizobium helmanticense sp. nov. is proposed, and the type strain is CSLC115NT (= LMG 29734T=CECT 9168T).
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Mesorhizobium helmanticense sp nov isolated from lotus corniculatus nodules
International Journal of Systematic and Evolutionary Microbiology, 2017Co-Authors: Marta Marcosgarcia, Martha Helena Ramirezbahena, Encarna Velázquez, Alvaro Peix, Esther Menendez, Pedro F Mateos, Raul RivasAbstract:In this study, three strains belonging to the genus Mesorhizobium , CSLC115NT, CSLC19N and CSLC37N, isolated from Lotus corniculatus nodules in Spain, were characterized. Their 16S rRNA gene sequences were closely related to those of Mesorhizobium metallidurans STM 2683T, Mesorhizobium tianshanense A-1BST, Mesorhizobium tarimense CCBAU 83306T, Mesorhizobium gobiense CCBAU 83330T and Mesorhizobium caraganae CCBAU 11299T with similarity values higher than 99.7 %. The analysis of concatenated recA and glnII genes showed that the most closely related type strains were M. metallidurans STM 2683T, M. tianshanense A-1BST and M. tarimense CCBAU 83306T with 96, 95 and 94 % similarity values in the recA gene and 95, 94 and 94 % in the glnII gene, respectively. M. metallidurans LMG 24485T, M. tianshanense USDA 3592T and M. tarimense LMG 24338T showed means of 44, 41 and 42 % DNA–DNA relatedness, respectively, with respect to strain CSLC115NT. The major fatty acids were those from summed feature 8 (C18 : 1ω7c/C18 : 1ω6c), C16 : 0 and C18 : 1ω7c 11-methyl. The results of phenotypic characterization support that the L. corniculatus nodulating strains analysed in this work belong to a novel species of the genus Mesorhizobium for which the name Mesorhizobium helmanticense sp. nov. is proposed, and the type strain is CSLC115NT (= LMG 29734T=CECT 9168T).
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Mesorhizobium olivaresii sp nov isolated from lotus corniculatus nodules
Systematic and Applied Microbiology, 2016Co-Authors: Maria J Lorite, Alvaro Peix, Jose David Floresfelix, Juan Sanjuán, Encarna VelázquezAbstract:Abstract In this study four Mesorhizobium strains isolated from Lotus corniculatus nodules in Granada (Spain) were characterized. Their 16S rRNA gene sequences were closely related to those of M. albiziae LMG 23507T and M. chacoense Pr5T showing 99.4 and 99.2% similarity values, respectively. The analysis of concatenated rpoB, recA, atpD and glnII genes showed they formed a cluster with internal similarities higher than 97%. The closest species also were M. albiziae LMG 23507T and M. chacoense Pr5T showing similarity values lower than 92% in rpoB, recA and glnII genes and lower than 96.5% in the atpD gene. These results indicated that the L. corniculatus strains belong to a new species of genus Mesorhizobium which was confirmed by DNA–DNA hybridization and phenotypic characterization. Therefore a new species with the name Mesorhizobium olivaresii sp. nov. is proposed, and the type strain is CPS13T (LMG 29295T = CECT 9099T).
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mesorhizobial strains nodulating anagyris latifolia and lotus berthelotii in tamadaya ravine tenerife canary islands are two symbiovars of the same species Mesorhizobium tamadayense sp nov
Systematic and Applied Microbiology, 2012Co-Authors: Martha Helena Ramirezbahena, Encarna Velázquez, Mariano Hernández-gil, Alvaro Peix, Milagros LeonbarriosAbstract:Abstract Barranco de Tamadaya is a deep ravine located in southern Tenerife, which is included within a protected area where several endemic plants grow. Among them, two legumes are catalogued as critically endangered, Anagyris latifolia and Lotus berthelotii. Rhizobial strains isolated from their root nodules grown in soil samples from this ravine harboured symbiotic genes belonging to two distant symbiovars, but they shared identical 16S rRNA gene sequences (rrs). The phylogeny based on the rrs sequences placed these isolates in a separate subbranch that did not include any of the currently recognised Mesorhizobium species, but the resolution of the ribosomal tree did not permit further taxonomic conclusions. Nevertheless, multilocus sequence analysis (MLSA) of four housekeeping genes (atpD, recA, glnII and dnaK) and the rrs gene generated a highly supported Bayesian phylogeny, identifying these isolates as a new Mesorhizobium lineage. DNA–DNA hybridisation homology percentages were lower than 30% compared to type strains of the closest related species, and supported the phylogenetic data. Phenotypic characterisation also distinguished this lineage from the other closest Mesorhizobium species. The polyphasic approach thus confirmed that the isolates represented a novel species for which we propose the name Mesorhizobium tamadayense sp. nov. The type strain is Ala-3T (CECT 8040T, LMG 26736T).
En Tao Wang - One of the best experts on this subject based on the ideXlab platform.
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Mesorhizobium wenxiniae sp nov isolated from chickpea cicer arietinum l in china
International Journal of Systematic and Evolutionary Microbiology, 2018Co-Authors: Jun Jie Zhang, Yimin Shang, Philippe De Lajudie, Zhiyan Zhang, Wen-feng Chen, En Tao WangAbstract:Three chickpea rhizobial strains (WYCCWR 10195T=S1-3-7, WYCCWR 10198=S1-4-3 and WYCCWR 10200=S1-5-1) isolated from Northwest China formed a group affiliated to Mesorhizobium based on 16S rRNA gene sequence comparison. To clarify their species status, multilocus sequence analysis and average nucleotide identity (ANI) values of whole genome sequences between the novel group and the type strains of the related species were further performed. Similarities of 95.7–96.6 % in the concatenated sequences of atpD-recA-glnII and 91.9–93.1 % of ANI values to the closest-related species Mesorhizobium muleiense , Mesorhizobium mediterraneum and Mesorhizobium temperatum demonstrated the novel group a unique genospecies. The most abundant fatty acid in cells of WYCCWR 10195T were C19 : 0 cyclo ω8c (51.4 %), followed by C18 : 1 ω7c 11-methyl (9.5 %) and C16 : 0 (9.3 %). Its genome size was 6.37 Mbp, comprising 6633 predicted genes with a DNA G+C content of 61.9 mol%. The similarities of 99.0–99.8 % for the nodC gene and 98.3–99.44 % for the nifH gene to those of the chickpea rhizobial species and nodulation with Cicer arietinum L. confirmed the strains of the new genospecies as symbiovar ciceri. The weak utilization of most of the tested sugars/organic acids and non-utilization of l(+)-rhamnose, l-cysteine and l-glycine as sole carbon source, tolerance to 1 % (w/v) NaCl, resistance to 5 µg ml−1 chloromycetin and non-hydrolysis of l-tyrosine distinguished the novel group from the related species and supported this group as a novel species, for which the name Mesorhizobium wenxiniae sp. nov. is proposed, with WYCCWR 10195T (=S1-3-7=HAMBI 3692T=LMG 30254T) as the type strain.
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evolutionarily conserved node nodo t1ss and hydrogenase system in rhizobia of astragalus membranaceus and caragana intermedia
Frontiers in Microbiology, 2017Co-Authors: Wen Xin Chen, En Tao Wang, Chang Fu Tian, Hui Yan, Jian Bo Xie, Na Yuan, Liang Zhong, Wen-feng ChenAbstract:Mesorhizobium species are the main microsymbionts associated with the medicinal or sand-fixation plants Astragalus membranaceus and Caragana intermedia (AC) in temperate regions of China, while all the Mesorhizobium strains isolated from each of these plants could nodulate both of them. However, Rhizobium yanglingense strain CCBAU01603 could nodulate AC plants and it's a high efficiency symbiotic and competitive strain with Caragana. Therefore, the common features shared by these symbiotic rhizobia in genera of Mesorhizobium and Rhizobium still remained undiscovered. In order to study the genomic background influencing the host preference of these AC symbiotic strains, the whole genomes of two (M. silamurunense CCBAU01550, M. silamurunense CCBAU45272) and five representative strains (M. septentrionale CCBAU01583, M. amorphae CCBAU01570, M. caraganae CCBAU01502, M. temperatum CCBAU01399, and R. yanglingense CCBAU01603) originally isolated from AC plants were sequenced, respectively. As results, type III secretion systems (T3SS) of AC rhizobia evolved in an irregular pattern, while an evolutionarily specific region including nodE, nodO, T1SS, and a hydrogenase system was detected to be conserved in all these AC rhizobia. Moreover, nodO was verified to be prevalently distributed in other AC rhizobia and was presumed as a factor affecting the nodule formation process. In conclusion, this research interpreted the multifactorial features of the AC rhizobia that may be associated with their host specificity at cross-nodulation group, including nodE, nodZ, T1SS as the possible main determinants; and nodO, hydrogenase system, and T3SS as factors regulating the bacteroid formation or nitrogen fixation efficiency.
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genotypic alteration and competitive nodulation of Mesorhizobium muleiense against exotic chickpea rhizobia in alkaline soils
Systematic and Applied Microbiology, 2014Co-Authors: Jun Jie Zhang, Wen-feng Chen, En Tao Wang, Tao Yu, Wen Xin ChenAbstract:Abstract Mesorhizobium muleiense , Mesorhizobium mediterraneum and Mesorhizobium ciceri are chickpea ( Cicer arietinum L.) rhizobia that share a high similarity of the symbiotic genes nodC and nifH , but they have different geographic distributions. M. muleiense has been isolated and found only in alkaline soils of Xinjiang, China, whereas the other two strains have been found in the Mediterranean and India. To investigate the species stability of M. muleiense during natural evolution and its capability of competitive nodulation against the other two exotic species, re-sampling of nodules in the field and competition experiments between the three species were conducted. The results showed that the predominant microsymbiont associated with chickpea grown in Xinjiang was still M. muleiense , but the predominant genotypes of M. muleiense had changed significantly during the four years since a previous survey. The data also showed that M. mediterraneum and M. ciceri were more competitive than the residential strain of M. muleiense CCBAU 83963 T in sterilized vermiculite or soils from Xinjiang. However, in non-sterilized soils, M. muleiense was the predominant nodule occupier. These results indicated that natural or adapting evolution of M. muleiense was occurring in fields subjected to changing environmental factors. In addition, the biogeography and symbiotic associations of rhizobia with their host legumes were also influenced by biological factors in the soil, such as indigenous rhizobia and other organisms.
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Mesorhizobium qingshengii sp nov isolated from effective nodules of astragalus sinicus
International Journal of Systematic and Evolutionary Microbiology, 2013Co-Authors: Wen Tao Zheng, En Tao Wang, Jun Jie Zhang, Xiao Xia Zhang, Rui Wang, Ying Li, Wen Xin ChenAbstract:In a study on the diversity of rhizobia isolated from root nodules of Astragalus sinicus, five strains showed identical 16S rRNA gene sequences. They were related most closely to the type strains of Mesorhizobium loti , Mesorhizobium shangrilense , Mesorhizobium ciceri and Mesorhizobium australicum , with sequence similarities of 99.6–99.8 %. A polyphasic approach, including 16S–23S intergenic spacer (IGS) RFLP, comparative sequence analysis of 16S rRNA, atpD, glnII and recA genes, DNA–DNA hybridization and phenotypic tests, clustered the five isolates into a coherent group distinct from all recognized Mesorhizobium species. Except for strain CCBAU 33446, from which no symbiotic gene was detected, the four remaining strains shared identical nifH and nodC gene sequences and nodulated with Astragalus sinicus. In addition, these five strains showed similar but different fingerprints in IGS-RFLP and BOX-repeat-based PCR, indicating that they were not clones of the same strain. They were also distinguished from recognized Mesorhizobium species by several phenotypic features and fatty acid profiles. Based upon all the results, we suggest that the five strains represent a novel species for which the name Mesorhizobium qingshengii sp. nov. is proposed. The type strain is CCBAU 33460T ( = CGMCC 1.12097T = LMG 26793T = HAMBI 3277T). The DNA G+C content of the type strain is 59.52 mol% (T m).
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Mesorhizobium muleiense sp nov nodulating with cicer arietinum l
International Journal of Systematic and Evolutionary Microbiology, 2012Co-Authors: Jun Jie Zhang, En Tao Wang, Wen-feng Chen, Xiao Xia Zhang, Yan Li, Wen Xin ChenAbstract:Three chickpea rhizobial strains (CCBAU 83963T, CCBAU 83939 and CCBAU 83908), which were identified previously as representing a distinctive genospecies, were further studied here and compared taxonomically with related species in the genus Mesorhizobium . Results from SDS-PAGE of whole-cell soluble proteins revealed differences from closely related recognized species of the genus Mesorhizobium . Levels of DNA–DNA relatedness were 15.28–50.97 % between strain CCBAU 83963T and the type strains of recognized Mesorhizobium species (except for Mesorhizobium thiogangeticum ). Strain CCBAU 83963T contained fatty acids characteristic of members of the genus Mesorhizobium , but it possessed high concentrations of C19 : 0 cyclo ω8c and iso-C17 : 0. Strain CCBAU 83963T had phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol as major polar lipids, and an ornithine-containing lipid, phosphatidyl-N-dimethylethanolamine and cardiolipin as minor components. Nodulation tests demonstrated the distinct symbiotic character of strain CCBAU 83963T; only Cicer arietinum, its host plant, could be invaded to form effective nitrogen-fixing nodules. The narrow spectrum of utilization of sole carbon sources, lower resistance to antibiotics, and NaCl, pH and temperature growth ranges differentiated these novel rhizobia from recognized species of the genus Mesorhizobium . Based on the data presented, the three novel rhizobial strains are considered to represent a novel species of the genus Mesorhizobium , for which the name Mesorhizobium muleiense sp. nov. is proposed. The type strain is CCBAU 83963T ( = HAMBI 3264T = CGMCC 1.11022T).
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Mesorhizobium carmichaelinearum sp nov isolated from carmichaelineae spp root nodules
International Journal of Systematic and Evolutionary Microbiology, 2019Co-Authors: Sofie E De Meyer, Euan K James, M. Andrews, Anne WillemsAbstract:Five strains of Gram-stain-negative, rod-shaped bacteria were isolated from Carmichaelia and Montigena root nodules. Based on 16S rRNA gene phylogeny, they were shown to belong to the genus Mesorhizobium , and to be most closely related to Mesorhizobium jarvisii ATCC 33669T (100–99.6 % sequence similarity), Mesorhizobium huakuii IAM 14158T (99.9–99.6 %), Mesorhizobium japonicum MAFF303099T (99.8–99.6 %) and Mesorhizobium erdmanii USDA 3471T (99.8–99.5 %). Additionally, the strains formed distinct groups based on housekeeping gene analysis and were most closely related to M. jarvisii ATCC 33669T (89.6–89.5 and 97.6–97.3 % sequence similarity for glnII and recA, respectively), M. erdmanii USDA 3471T (94.3–94.0 and 94.9–94.1 %), M. japonicum MAFF303099T (90.0–89.9 and 96.7–96.2 %) and M. huakuii IAM 14158T (89.9–90.0 and 95.4–94.9 %). Chemotaxonomic data supported the assignment of the strains to the genus Mesorhizobium and DNA–DNA hybridizations, average nucleotide identity analysis, matrix-assisted laser desorption ionization time-of-flight MS analysis, physiological and biochemical tests differentiated them genotypically and phenotypically from their nearest neighbouring species. Therefore, these strains are considered to represent a novel species, for which the name Mesorhizobium carmichaelinearum sp. nov. is proposed. The type strain is ICMP 18942T (=MonP1N1T=LMG 28414T).
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Mesorhizobium calcicola sp nov Mesorhizobium waitakense sp nov Mesorhizobium sophorae sp nov Mesorhizobium newzealandense sp nov and Mesorhizobium kowhaii sp nov isolated from sophora root nodules
International Journal of Systematic and Evolutionary Microbiology, 2016Co-Authors: Sofie E De Meyer, P. B. Heenan, M. Andrews, Anne WillemsAbstract:In total, 31 strains of Gram-stain-negative, rod-shaped bacteria were isolated from Sophora root nodules and authenticated as rhizobia on this host. Based on 16S rRNA gene phylogeny, they were shown to belong to the genus Mesorhizobium, with the representative strains ICMP 19560T, ICMP 19523T, ICMP 19535T, ICMP 19545T and ICMP 19512T being related most closely to Mesorhizobium sangaii SCAU7T (99.9–99.6 % similarity), Mesorhizobium cantuariense ICMP 19515T (99.7–99.6 %) and Mesorhizobium ciceri UMP-CA7T (99.7–99.5 %). Additionally, the novel strains formed distinct groups based on housekeeping gene sequence analysis and were closely related to Mesorhizobium waimense ICMP 19557T (93.5–94.9, 92.5–95.6 and 94.2–96.0 %), M. cantuariense ICMP 19515T (93.1–97.7, 93.5–95.4 and 94.8–96.8 %) and M. ciceri UMP-CA7T (93.2–97.2, 94.6–96.8 and 95.5–97.3 %) for glnII, recA and rpoB, respectively. Chemotaxonomic data supported the assignment of the strains to the genus Mesorhizobium, and DNA–DNA hybridizations, matrix-assisted laser desorption/ionization time-of-flight MS analysis, enterobacterial repetitive intergenic consensus PCR, physiological and biochemical tests allowed the genotypic and phenotypic differentiation from their nearest neighbouring species. Therefore, these strains represent five novel species for which the names Mesorhizobium calcicola sp. nov. (type strain ICMP 19560T = LMG 28224T = HAMBI 3609T), Mesorhizobium waitakense sp. nov. (type strain ICMP 19523T = LMG 28227T = HAMBI 3605T), Mesorhizobium sophorae sp. nov. (type strain ICMP 19535T = LMG 28223T = HAMBI 3606T), Mesorhizobium newzealandense sp. nov. (type strain ICMP 19545T = LMG 28226T = HAMBI 3607T) and Mesorhizobium kowhaii sp. nov. (type strain ICMP 19512T = LMG 28222T = HAMBI 3603T) are proposed.
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Mesorhizobium waimense sp nov isolated from sophora longicarinata root nodules and Mesorhizobium cantuariense sp nov isolated from sophora microphylla root nodules
International Journal of Systematic and Evolutionary Microbiology, 2015Co-Authors: Sofie E De Meyer, P. B. Heenan, M. Andrews, Anne WillemsAbstract:In total 14 strains of Gram-stain-negative, rod-shaped bacteria were isolated from Sophora longicarinata and Sophora microphylla root nodules and authenticated as rhizobia on these hosts. Based on the 16S rRNA gene phylogeny, they were shown to belong to the genus Mesorhizobium, and the strains from S. longicarinata were most closely related to Mesorhizobium amorphae ACCC 19665(T) (99.8-99.9 %), Mesorhizobium huakuii IAM 14158(T) (99.8-99.9 %), Mesorhizobium loti USDA 3471(T) (99.5-99.9 %) and Mesorhizobium septentrionale SDW 014(T) (99.6-99.8 %), whilst the strains from S. microphylla were most closely related to Mesorhizobium ciceri UPM-Ca7(T) (99.8-99.9 %), Mesorhizobium qingshengii CCBAU 33460(T) (99.7 %) and Mesorhizobium shangrilense CCBAU 65327(T) (99.6 %). Additionally, these strains formed two distinct groups in phylogenetic trees of the housekeeping genes glnll, recA and rpoB. Chemotaxonomic data, including fatty acid profiles, supported the assignment of the strains to the genus Mesorhizobium and allowed differentiation from the closest neighbours. Results of DNA-DNA hybridizations, MALDI- TOF MS analysis, ERIC-PCR, and physiological and biochemical tests allowed genotypic and phenotypic differentiation of our strains from their closest neighbouring species. Therefore, the strains isolated from S. longicarinata and S. microphylla represent two novel species for which the names Mesorhizobium waimense sp. nov. (ICMP 19557(T)=LMG 28228(T)=HAMBI 3608(T)) and Mesorhizobium cantuariense sp. nov. (ICMP 19515(T)=LMG 28225(T)=HAMBI 3604(T)), are proposed respectively.
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Mesorhizobium shonense sp nov Mesorhizobium hawassense sp nov and Mesorhizobium abyssinicae sp nov isolated from root nodules of different agroforestry legume trees
International Journal of Systematic and Evolutionary Microbiology, 2013Co-Authors: Tulu Degefu, Endalkachew Woldemeskel, Ilse Cleenwerck, Anne Willems, Asa FrostegardAbstract: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 (i59%). 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 AC39a T (5LMG 26966 T 5HAMBI 3295 T ), AC99b T (5LMG 26968 T 5HAMBI 3301 T ) and AC98c T (5LMG 26967 T 5HAMBI 3306 T ) are proposed as type strains for the respective novel species.
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Mesorhizobium australicum sp nov and Mesorhizobium opportunistum sp nov isolated from biserrula pelecinus l in australia
International Journal of Systematic and Evolutionary Microbiology, 2009Co-Authors: Kemanthi G. Nandasena, R P Tiwari, G W Ohara, Anne Willems, J.g. HowiesonAbstract:Biserrula pelecinus L. is a pasture legume that was introduced to Australia from the Mediterranean basin in 1993. Although the native rhizobial population could not nodulate B. pelecinus at the time of its introduction, recent research has shown the emergence of a diversity of strains (novel isolates) that are able to do so. Three novel isolates, WSM2073T, WSM2074 and WSM2076, had nearly identical 16S rRNA gene sequences, and clustered separately with all recognized species of the genus Mesorhizobium. Conversely, the novel isolate WSM2075T had >23 nt mismatches with the above three isolates. All four novel isolates shared 97-99% 16S rRNA gene sequence similarity with the type strains of all recognized Mesorhizobium species. However, strains WSM2073T, WSM2074 and WSM2076 showed <95.2% dnaK gene sequence similarity to the type strains of recognized Mesorhizobium species, and <92.9% to WSM2075T (which also shared <95.5% dnaK gene sequence similarity to the type strains of recognized Mesorhizobium species). Results for GSII gene sequencing were consistent with those for the dnaK gene. The fatty acid profiles of the novel isolates were diagnostic of root-nodule bacteria, but did not match those of recognized bacterial species. Strain WSM2075T had a significantly different fatty acid profile from the other three isolates. The above results indicated that strains WSM2073T, WSM2074 and WSM2076 represent the same species. Strain WSM2073T showed <45% DNA-DNA relatedness and WSM2075T <50% DNA-DNA relatedness with the type strains of recognized Mesorhizobium species; these two novel isolates shared 59% DNA-DNA relatedness. Collectively, these data indicate that strains WSM2073T, WSM2074 and WSM2076, and strain WSM2075T belong to two novel species of the genus Mesorhizobium, for which the names Mesorhizobium australicum sp. nov. and Mesorhizobium opportunistum sp. nov. are proposed, respectively. The type strain of Mesorhizobium australicum sp. nov. is WSM2073T (=LMG 24608T=HAMBI 3006T) and the type strain of Mesorhizobium opportunistum sp. nov. is WSM2075T (=LMG 24607T=HAMBI 3007T).