- [Show abstract] [Hide abstract] ABSTRACT: Rhizobial strains from root nodules of Astragalus mongholicus and soybean (Glycine max) were characterized phylogenetically as members of the genus Ensifer (formerly named Sinorhizobium), based on 16S rRNA gene comparisons. Results based upon concatenated sequence analysis of three housekeeping genes (recA, atpD and glnII, ≤ 93.8% similarities to known species) and average nucleotide identities (ANI) values of whole genome sequence comparisons (ranged from 89.6% to 83.4% to Ensifer fredii and Ensifer saheli, respectively) indicated the distinct positions of these novel strains within the genus Ensifer. Phylogeny of symbiotic genes (nodC and nifH) of three strains clustered them with rhizobial species Ensifer fredii and Ensifer sojae, both isolated from nodules of Glycine max. Cross-nodulation tests showed that the representative strain CCBAU 23380T could form root nodules with nitrogen fixation capability on Glycine soja, Albizia julibrissin, Vigna unguiculata and Cajanus cajan , but failed to nodulate on Astragalus mongholicus, its original host legume. Strain CCBAU 23380T formed inefficient nodules on Glycine max and it did not contain 18:0, 18:1 ω7c 11-methyl and summed feature 1 fatty acids, which differed from other related strains. Failure to utilize malonic acid as a carbon source distinguished strain CCBAU 23380T from the type strains of related species. The genome size of CCBAU 23380T was 6.0 Mbp, comprising 5624 predicted genes with DNA G+C content of 62.4 mol%. Based on the results above, a novel species, Ensifer glycinis sp. nov., was proposed, with CCBAU 23380T (= LMG 29231T = HAMBI 3645T) as the type strain.
- [Show abstract] [Hide abstract] ABSTRACT: Seven slow-growing rhizobia isolated from effective nodules of Arachis hypogaea were assigned to the genus Bradyrhizobium by sharing 96.3-99.9% similarities of 16S rRNA gene sequences with the recognized Bradyrhizobium species. Multilocus sequence analysis of glnII, recA, gyrB and dnaK genes indicated that the seven strains belonged to two novel species represented by CCBAU 51649T and CCBAU 53363T. Strain CCBAU 51649T had 94%, 93.4%, 92.3% and 94.9% and CCBAU 53363T had 91.4%, 94.5%, 94.6% and 97.7% sequences similarities for glnII, recA, gyrB and dnaK genes with respect to the closest related species Bradyrhizobium manausense BR3351T or Bradyrhizobium yuanmingense CCBAU 10071T, respectively. Summed feature 8 and C16:0 were the predominant components for strains CCBAU 51649T and CCBAU 53363T. DNA-DNA hybridization and analysis of phenotypic characteristics also distinguished these strains from the closest related Bradyrhizobium species. The two species formed effective nodules in Arachis hypogaea, Lablab purpureus and Aeschynomene indica, and they have identical nodA to strain PJI237 but are phylogenetically divergent to other available nodA genes with less than 66% similarity. Based in these results, Bradyrhizobium guangdongense sp. nov. and Bradyrhizobium guangxiense sp. nov. are proposed, and CCBAU 51649T (=CGMCC 1.15034T =LMG 28620T) and CCBAU 53363T (=CGMCC 1.15035T =LMG 28621T) are designated as the type strains, respectively.
- [Show abstract] [Hide abstract] ABSTRACT: Four rhizobia like strains, isolated from root nodules of Pisum sativum and Vicia faba grown in Anhui and Jiangxi Provinces of China, were grouped into the genus Rhizobium but were distinct from all recognized Rhizobium species by phylogenetic analysis of 16S rRNA and housekeeping genes. The combined sequence of housekeeping genes atpD, recA and glnII for strains CCBAU 23252T was 86.9% to 95% similar to those of known Rhizobium species. All the four strains had nodC and nifH genes and could form effective nodules with Pisum sativum and Vicia faba, and ineffective nodules with Phaseolus vulgaris, but did not nodulate Glycine max, Arachis hypogaea, Medicago sativa, Trifolium repens or Lablab purpureus in cross-nodulation tests. Fatty acid composition, DNA-DNA relatedness and a series of phenotypic tests also separated these strains from the closely related species. Based on all the evidence, we propose a novel species Rhizobium anhuiense sp. nov., and designate CCBAU 23252T (=CGMCC 1.12621T =LMG 27729T) as the type strain. This strain was isolated from a root nodule of Vicia faba and has a GC content of 61.1 mol% (Tm).
- [Show abstract] [Hide abstract] ABSTRACT: Six slow-growing rhizobial strains isolated from effective nodules of Erythrophleum fordii were classified into the genus Bradyrhizobium based on 16S rRNA gene sequence. The results of multilocus sequence analysis of recA, glnII and gyrB genes and IGS sequence phylogeny indicated that the six strains were two novel species represented by CCBAU 53325T and CCBAU 51502T, which were consistent with the results of DNA-DNA hybridization. CCBAU 53325T had 17.65%-25.59% and CCBAU 51502T had 22.69%-44.58% DNA-DNA relatedness with five closely related type strains including B. elkanii USDA 76T, B. pachyrhizi LMG 24246T, B. lablabi CCBAU 23086T, B. jicamae LMG 24556T, and B. japonicum USDA 6T. In addition, analysis of phenotype characteristics and fatty acid profile also distinguished the test strains from the defined species of Bradyrhizobium. Two novel species, Bradyrhizobium erythrophlei sp. nov. represented by the type strain CCBAU 53325T (= HAMBI 3614T = CGMCC 1.13002T = LMG 28425T) and Bradyrhizobium ferriligni sp. nov. represented by the type strain CCBAU 51502T (= HAMBI 3613T = CGMCC 1.13001T) were proposed.
- [Show abstract] [Hide abstract] ABSTRACT: A Gram-negative, white, non-motile, rod shaped bacterial strain BN-19T was isolated from a root nodule of groundnut (Arachis hypogaea) in Pakistan. Phylogenetic analysis based on 16S rRNA gene sequence revealed that strain BN-19T formed a subclade in the genus Rhizobium together with Rhizobium alkalisoli CCBAU 01393T, Rhizobium vignae CCBAU 05176T, Rhizobium huautlense SO2T and Rhizobium tarimense PL-41T with sequence similarities of 97.5, 97.3, 97.2 and 97.1 % respectively. Sequence analysis of housekeeping genes atpD, glnII and recA (with sequence similarities of ≤92 %) confirmed the unique position of BN-19T in the genus Rhizobium. DNA–DNA relatedness between the strain BN-19T and R. alkalisoli CCBAU 01393T, R. vignae CCBAU 05176T, R. huautlense SO2T and R. tarimense PL-41T were 20.6, 22.5, 15.9 and 20.5 % respectively, further confirming that BN-19T represents a novel species in the genus Rhizobium. The DNA G + C content was 60.1 mol%. The dominant fatty acids of strain BN-19T were C19:0 cyclo ω8c, summed feature 2 (C14:0 3OH and/or C16:1 iso I) and summed feature 8 (C18:1 ω7c). Some phenotypic features also differentiate the strain BN-19T from the related species. On the basis of these results, strain BN-19T is considered to represent a novel species in the genus Rhizobium, for which the name Rhizobium pakistanensis sp. nov. is proposed. The type strain is BN-19T (=LMG 27895T = CCBAU 101086T).
- [Show abstract] [Hide abstract] ABSTRACT: Two novel Gram-negative strains (CCBAU 03422T and CCBAU 03415) isolated from root nodules of Sophora flavescens were phylogenetically classified into the genus of Phyllobacterium based on the comparative analysis of 16S rRNA and atpD genes. They showed 99.8% rRNA gene sequence similarities to Phyllobacterium brassicacearum LMG 22836T, and CCBAU 03422T showed 91.2% and 88.6% atpD gene similarities to strains P. endophyticum LMG 26470T and P. brassicacearum LMG 22836T, respectively. Strain CCBAU 03422T contained Q-10 as its major quinone and showed cellular fatty acid profile, carbon source utilization and other phenotypic characteristics differing from type strains of the related species. DNA-DNA relatedness (lower than 48.8%) further confirmed the differences between the novel strains and the type strains of related species. Strain CCBAU 03422T could nodulate and fix nitrogen effectively on its original host plant, Sophora flavescens. Based upon the studies mentioned above, a novel species named as Phyllobacterium sophorae is proposed and the type strain is CCBAU 03422T (= A-6-3T = LMG 27899T = HAMBI 3508T).
- [Show abstract] [Hide abstract] ABSTRACT: Three common bean strains, 23C2 (Tunisia), Gr42 (Spain) and IE4868 (Mexico), which were identified previously as representing a genomic group closely related to Rhizobium gallicum, are further studied here. Their 16S rRNA gene sequence showed 98.5%-99% of similarity respectively with Rhizobium loessense CCBAU 7190BT, R. gallicum R602spT, R. mongolense USDA 1844T and R. yanglingense CCBAU 71623T. Phylogenetic analysis based on recA, atpD, dnaK and thrC showed that these strains were closely related and could be distinguished from the four type strains. Strains 23C2, Gr42 and IE4868 could be also differentiated from their closest phylogenetic neighbors by their phenotypic and physiological properties and their fatty acid contents. All three strains harbored symbiotic genes specific of biovar gallicum. Levels of DNA/DNA relatedness between strain 23C2 and the type strains of R. loessense, R. mongolense, R. gallicum and R. yanglingense ranged from 58.1-61.5%. The G+C content of the genomic DNA of strain 23C2 was 59.52%. On the basis of these data, strains 23C2, Gr42 and IE4868 were considered as a novel species of the genus Rhizobium for which the name Rhizobium azibense is proposed. Strain 23C2T (=CCBAU 101087= HAMBI3541) was designated as the type strain.
- [Show abstract] [Hide abstract] ABSTRACT: Twenty-three bacterial strains isolated from root nodules of Arachis hypogaea and Lablab purpureus grown in five provinces of China were classified as a novel group within the genus Bradyrhizobium by analyses of PCR-based RFLP of the 16S rRNA gene and 16S-23S IGS. To determine their taxonomic position, four representative strains were further characterized. The comparative sequence analyses of 16S rRNA and six housekeeping genes clustered the four strains into a distinctive group closely related to the defined species Bradyrhizobium liaoningense, Bradyrhizobium yuanmingense, Bradyrhizobium huanghuaihaiense, Bradyrhizobium japonicum and Bradyrhizobium daqingense. The DNA-DNA relatedness between the reference strain of the novel group, CCBAU 051107(T), and the corresponding type strains of the five mentioned species varied between 46.05% and 13.64%. The nodC and nifH genes of CCBAU 051107(T) were phylogenetically divergent from those of the reference strains for the related species. The four representative strains could nodulate with A. hypogaea and L. purpureus. In addition, some phenotypic features differentiated the novel group from the related species. Based on all the results, we propose a new species Bradyrhizobium arachidis sp. nov. and designate CCBAU 051107(T) (=CGMCC 1.12100(T)=HAMBI 3281(T)=LMG 26795(T)) as the type strain, which was isolated from a root nodule of A. hypogaea and had a DNA G+C mol% of 60.1 (Tm).
- [Show abstract] [Hide abstract] ABSTRACT: Three bacterial isolates (CCBAU 101002(T), CCBAU 101000 and CCBAU 101001) originating from root nodules of the herbaceous legume Kummerowia stipulacea grown in the campus lawn of China Agricultural University were characterized with a polyphasic taxonomic approach. Comparative 16S rRNA gene sequence analysis showed that the isolates shared 99.85-99.92% sequence similarities and had the highest similarities to the type strains of Rhizobium mesoamericanum (99.31%), R. endophyticum (98.54%), R. tibeticum (98.38%) and R. grahamii (98.23%). Sequence similarity of four concatenated housekeeping genes (atpD, glnII, recA and rpoB) between CCBAU 101002(T) and its closest neighbor (R. grahamii) was 92.05%. DNA-DNA hybridization values between strain CCBAU 101002(T) and the four type strains of the most closely related Rhizobium species were less than 28.4±0.8%. The G+C mol% of the genomic DNA for strain CCBAU 101002(T) was 58.5% (Tm). The major respiratory quinone was ubiquinone (Q-10). Summed feature 8 (18:1ω7cis/18:1ω6cis) and 16:0 were the predominant fatty acids. Strain CCBAU 101002(T) contained phosphatidylcholine and phosphatidylethanolamine as major polar lipids, and phosphatidylglycerol and cardiolipin as minor ones. No glycolipid was detected. Unlike other strains, this novel species could utilize dulcite or sodium pyruvate as sole carbon sources and it was resistant to 2% (w/v) NaCl. On the basis of the polyphasic study, a new species Rhizobium cauense sp. nov. is proposed, with CCBAU 101002(T) (=LMG 26832(T)=HAMBI 3288(T)) as the type strain.
- [Show abstract] [Hide abstract] ABSTRACT: In a study on the diversity of rhizobia isolated from root nodules of Astragalus sinicus, five strains showed identical nucleotide sequences of 16S rRNA gene. They were most related to the type strains of Mesorhizobium loti, M. shangrilense, M. ciceri and M. australicum, with sequence similarities of 99.6 % to 99.8 %. A polyphasic approach, including 16S-23S 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 the defined Mesorhizobium species. Except the 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-PCR, indicating that they were not clones of the same strain. They were also distinguished from the defined species by some phenotypic features and fatty acid profiles. Based upon all the results, we propose a new species named as Mesorhizobium qingshengii sp. nov. and designated CCBAU 33460T (= CGMCC 1.12097T = LMG 26793T = HAMBI 3277T ) as the type strain. The DNA G+C mol % for the type strain is 59.52 % (Tm).
- [Show abstract] [Hide abstract] ABSTRACT: Three chickpea rhizobial strains (CCBAU 83963T, CCBAU 83939 and CCBAU 83908) which were identified previously as a distinctive genospecies were further studied and compared taxonomically to the related species in the genus of Mesorhizobium in the current studies. Results from SDS-PAGE of whole-cell soluble proteins showed their differences from other closely related known Mesorhizobium species. Values of DNA-DNA hybridization varied from 15.28 to 50.97% between the representative strain CCBAU 83963T and the type strains of the defined Mesorhizobium species (except for M. thiogangeticum). Representative strain CCBAU 83963T contained characteristic fatty acids similar to the components of other Mesorhizobium species, but it possessed the highest concentrations (44.88%) of 19:0 cyclo ω8c and 17:0 iso (3.62%). Strain CCBAU 83963T had phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) as its three major polar lipids, and ornithine-containing lipid (OL), phosphatidyl-N-dimethylethanolamine (DMPE) and cardiolipin (CL) as its three 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 fixation nodules. Narrow spectrum on the utilization of sole carbon sources, lower resistance to antibiotics, NaCl, pH and temperature differentiated these novel rhizobia from other related Mesorhizobium species. Based upon all the comparative analyses, a novel species Mesorhizobium muleiense sp. nov. was proposed with CCBAU 83963T (=HAMBI 3264T =CGMCC 1.11022T) as the type strain.
- [Show abstract] [Hide abstract] ABSTRACT: 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 11892(T) 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 01550(T) ( = HAMBI 3029(T) = LMG 24822(T)), and could form effective nodules on Astragalus membranaceus, Astragalus adsurgens and Caragana intermedia, and ineffective nodules on Phaseolus vulgaris in cross-nodulation tests.
- [Show abstract] [Hide abstract] ABSTRACT: Seven Rhizobium strains associated with various legume species grown in different geographical regions of China were defined into four genomic groups related to Rhizobium giardinii, based upon ribosomal intergenic spacer RFLP, phylogenies of 16S rRNA and housekeeping (atpD, recA and glnII) genes, and DNA relatedness. Three strains in group I were classified as R. giardinii, as they showed high gene sequence similarities (>97 %) and DNA relatedness (64.3-67.5 %) to R. giardinii H152(T). Groups II, III and IV differed from all defined Rhizobium species based upon the consensus of all analyses. As group II contained two strains that originated from two distinct populations, we propose this group as a novel species, Rhizobium herbae sp. nov., with strain CCBAU 83011(T) ( = LMG 25718(T) = HAMBI 3117(T)) as the type strain.
- [Show abstract] [Hide abstract] ABSTRACT: As an introduced plant, Lablab purpureus serves as a vegetable, herbal medicine, forage and green manure in China. In order to investigate the diversity of rhizobia associated with this plant, a total of 49 rhizobial strains isolated from ten provinces of Southern China were analyzed in the present study with restriction fragment length polymorphism and/or sequence analyses of housekeeping genes (16S rRNA, IGS, atpD, glnII and recA) and symbiotic genes (nifH and nodC). The results defined the L. purpureus rhizobia as 24 IGS-types within 15 rrs-IGS clusters or genomic species belonging to Bradyrhizobium, Rhizobium, Ensifer (synonym of Sinorhizobium) and Mesorhizobium. Bradyrhizobium spp. (81.6%) were the most abundant isolates, half of which were B. elkanii. Most of these rhizobia induced nodules on L. purpureus, but symbiotic genes were only amplified from the Bradyrhizobium and Rhizobium leguminosarum strains. The nodC and nifH phylogenetic trees defined five lineages corresponding to B. yuanmingense, B. japonicum, B. elkanii, B. jicamae and R. leguminosarum. The coherence of housekeeping and symbiotic gene phylogenies demonstrated that the symbiotic genes of the Lablab rhizobia were maintained mainly through vertical transfer. However, a putative lateral transfer of symbiotic genes was found in the B. liaoningense strain. The results in the present study clearly revealed that L. purpureus was a promiscuous host that formed nodules with diverse rhizobia, mainly Bradyrhizobium species, harboring different symbiotic genes.
- [Show abstract] [Hide abstract] ABSTRACT: A gram-positive, aerobic, motile rod, designated strain CCBAU 05776(T), was isolated from the inner tissues of a healthy soybean (Glycine max L.) root collected from an agricultural field in the countryside of Shijiazhuang city, Hebei Province, China. Phylogenetic analysis of the 16S rRNA gene indicated that this strain was most closely related to Bacillus muralis LMG 20238(T) and Bacillus simplex NBRC 15720(T) with similarity of 96.5 % and 96.3 %, respectively, lower than the suggested threshold (97.0 %) for separating bacterial species. In phenotypic characterization, the novel strain differed from the two most related species in that it did not hydrolyse casein or starch but could grow on MacConkey agar. It grew between 15 and 45 °C and tolerated up to 7 % NaCl (w/v). Strain CCBAU 05776(T) grew in media with pH 5.5 to 10 (optimal growth at pH 7.0-8.0). The predominant cellular fatty acids were iso-C(15 : 0) (40.81 %) and C(16 : 1)ω7c alcohol (10.61 %). The predominant isoprenoid quinone was menaquinone 7 (MK-7). The cell-wall peptidoglycan contained meso-diaminopimelic acid. The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The DNA G+C was 40.8 mol% (T(m)). DNA-DNA relatedness of the novel isolate with B. muralis and B. simplex was 42.4 % and 32.7 %, respectively. Based upon the consensus of phylogenetic and phenotypic analyses, strain CCBAU 05776(T) represents a novel species within the genus Bacillus, for which the name Bacillus endoradicis sp. nov. is proposed. The type strain is CCBAU 05776(T) ( = LMG 25492(T) = HAMBI 3097(T)).
- [Show abstract] [Hide abstract] ABSTRACT: A Gram-staining-negative bacterium, designated strain BLN2(T), was isolated from within the roots of reeds (Phragmites australis) in Beijing Cuihu Wetland (China) and characterized using a polyphasic taxonomic approach. The cells were yellow-pigmented, rod-shaped, strictly aerobic and devoid of flagella, but showed gliding motility. Strain BLN2(T) produced yellow, translucent, circular and convex colonies, with optimal growth at 30 °C and pH 7.0. The major respiratory quinone was menaquinone 6 (MK-6) and the predominant fatty acids were iso-C(15 : 0), summed feature 3 (comprising C(16 : 1)ω7c and/or C(16 : 1)ω6c), C(16 : 0) 3-OH, C(16 : 0,) iso-C(17 : 0) 3-OH and iso-C(15 : 0) 3-OH. The G+C content of the genomic DNA was 34.8 mol%. The 16S rRNA gene sequence analysis showed that strain BLN2(T) belonged to the genus Flavobacterium and was most closely related to Flavobacterium anhuiense CGMCC 1.6859(T) (97.0 % sequence similarity). The DNA-DNA relatedness between strain BLN2(T) and F. anhuiense CGMCC 1.6859(T) was 25.7 %. Based on the phenotypic data and phylogenetic inference presented, it is concluded that strain BLN2(T) represents a novel species within the genus Flavobacterium, for which the name Flavobacterium phragmitis sp. nov. is proposed. The type strain is BLN2(T) ( = DSM 23314(T) = CGMCC 1.10370(T)).
- [Show abstract] [Hide abstract] ABSTRACT: Four rhizobial strains, designated CCBAU 85046(T), CCBAU 85051, CCBAU 85048 and CCBAU 85049, isolated from root nodules of Oxytropis glabra grown in Tibet, China, were previously defined, using amplified 16S rRNA gene restriction analysis, as a novel group within the genus Rhizobium. To clarify their taxonomic position, these strains were further analysed and compared with reference strains of related bacteria using a polyphasic approach. The 16S rRNA gene analysis showed that the four isolates formed a distinct phylogenetic lineage in the genus Rhizobium. The isolates showed highest sequence similarity (97.8 %) to Rhizobium indigoferae CCBAU 71042(T). Phenotypic and physiological tests, DNA-DNA hybridization, phylogenetic analyses of housekeeping genes recA, atpD and glnII and fatty acid profiles also indicated that these four strains constitute a novel group distinct from recognized species of the genus Rhizobium. Based on this evidence, strains CCBAU 85046(T), CCBAU 85051, CCBAU 85048 and CCBAU 85049 represent a novel species in the genus Rhizobium, for which the name Rhizobium tubonense sp. nov. is proposed. The type strain is CCBAU 85046(T) (=LMG 25225(T) =HAMBI 3066(T)) and its DNA G+C content is 59.52 % (T(m)). Strain CCBAU 85046(T) could form effective nodules on plant species Vigna unguiculata and Medicago sativa but not on its host of origin Oxytropis glabra.
- [Show abstract] [Hide abstract] ABSTRACT: Five strains of bacteria isolated from nodules of Caragana bicolor and Caragana erinacea in Yunnan Province of China were classified within the genus Mesorhizobium in the class Alphaproteobacteria. The highest degree of 16S rRNA gene sequence similarity was determined to be to Mesorhizobium loti LMG 6125(T) (99.7 %) and Mesorhizobium ciceri UPM-Ca7(T) (99.7 %). Polyphasic taxonomic methods including SDS-PAGE of whole-cell soluble proteins, comparative housekeeping sequence analysis of atpD, glnII and recA, fatty acid profiles and a series of phenotypic and physiological tests allowed us to cluster the five strains into a coherent group while differentiating them from all previously established Mesorhizobium species. The DNA-DNA relatedness between the representative strain CCBAU 65327(T) and the type strains of M. loti and M. ciceri was 26.5 and 23.4 %, respectively, clearly indicating that strain CCBAU 65327(T) represents a novel species for which we propose the name Mesorhizobium shangrilense sp. nov. Strain CCBAU 65327(T) (=LMG 24762(T) =HAMBI 3050(T)) is designated as the type strain, and could nodulate Caragana microphylla, Caragana intermedia, Glycyrrhiza uralensis, Astragalus adsurgens, Vigna unguiculata, Vigna radiata and Phaseolus vulgaris in cross-nodulation tests.
- [Show abstract] [Hide abstract] ABSTRACT: An orange-coloured bacterium, CCBAU 05354(T), was isolated from the soybean rhizosphere following growth on NA medium. The sample was taken from a field in Hebei province, People's Republic of China. The cells were aerobic, Gram-stain-negative, short rods (0.4-0.6 x 0.7-1.7 microm) and non-motile. Growth occurred at 28 degrees C (not at 10 or 37 degrees C), pH 6.0-10.0, and in the presence of 0-1 % NaCl (w/v). Flexirubin pigment was produced and the cells were resistant to some antibiotics. A phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CCBAU 05354(T) was closely related to Niabella soli KACC 12604(T) (95.1 % sequence similarity). The predominant cellular fatty acids were iso-C(15 : 0), iso-C(15 : 1) G, iso-C(17 : 0) 3-OH and summed feature 3 (comprising C(16 : 1)omega7c and/or C(16 : 1)omega6c). The DNA G+C content was 42 mol%. On the basis of the phylogenetic, phenotypic and chemotaxonomic data, strain CCBAU 05354(T) represents a novel species of the genus Niabella, for which the name Niabella yanshanensis sp. nov. is proposed. The type strain is CCBAU 05354(T) (=LMG 24661(T) =HAMBI 3031(T)).
- [Show abstract] [Hide abstract] ABSTRACT: Five rhizobial strains representing the largest group in the genus Mesorhizobium associated with Caragana spp. in China were characterized taxonomically. Phylogenetic analysis based on 16S rRNA gene sequences indicated that these microsymbionts belonged to the genus Mesorhizobium, with Mesorhizobium tianshanense USDA 3592(T), Mesorhizobium temperatum SDW018(T) and Mesorhizobium mediterraneum UPM-Ca36(T) as the closest neighbours (>/=99.5 % 16S rRNA gene sequence similarity). Genotypic fingerprinting by whole-cell protein electrophoresis, DNA-DNA hybridization, comparative housekeeping sequence analysis of the atpD, glnII and recA genes, fatty acid profiles and a series of phenotypic and physiological tests allowed the novel group to be differentiated from all previously recognized species of the genus Mesorhizobium. This group therefore represents a novel species, for which the name Mesorhizobium caraganae sp. nov. is proposed with the type strain CCBAU 11299(T) (=LMG 24397(T)=HAMBI 2990(T)). Cross-inoculation tests showed that strain CCBAU 11299(T) could form effective nodules on Caragana microphylla, Caragana intermedia, Glycyrrhiza uralensis, Astragalus adsurgens and Phaseolus vulgaris.
Chinese Academy of Agricultural Sciences
Peping, Beijing, China
- Institute of Agricultural Resources and Regional Planning