Jiao Y.S.,State Key Laboratory of Agrobiotechnology |
Jiao Y.S.,China Agricultural University |
Jiao Y.S.,MOA Key Laboratory of Soil Microbiology |
Yan H.,State Key Laboratory of Agrobiotechnology |
And 22 more authors.
International Journal of Systematic and Evolutionary Microbiology | Year: 2015
Five bacterial strains representing 45 isolates originated from root nodules of the medicinal legume Sophora flavescens were defined as two novel groups in the genus Rhizobium based on their phylogenetic relationships estimated from 16S rRNA genes and the housekeeping genes recA, glnII and atpD. These groups were distantly related to Rhizobium leguminosarum USDA 2370T (95.6% similarity for group I) and Rhizobium phaseoli ATCC 14482T (93.4% similarity for group II) in multilocus sequence analysis. In DNA–DNA hybridization experiments, the reference strains CCBAU 03386T (group I) and CCBAU 03470T (group II) showed levels of relatedness of 17.9–57.8 and 11.0–42.9%, respectively, with the type strains of related species. Both strains CCBAU 03386T and CCBAU 03470T contained ubiquinone 10 (Q-10) as the major respiratory quinone and possessed 16: 0, 18:0, 19:0 cyclo v8c, summed feature 8 and summed feature 2 as major fatty acids, but did not contain 20:3 v6,8,12c. Phenotypic features distinguishing both groups from all closely related species of the genus Rhizobium were found. Therefore, two novel species, Rhizobium sophorae sp. nov. for group I (type strain CCBAU 03386T5E5T5LMG 27901T5HAMBI 3615T) and Rhizobium sophoriradicis sp. nov. for group II (type strain CCBAU 03470T5C-5-1T5LMG 27898T5HAMBI 3510T), are proposed. Both groups were able to nodulate Phaseolus vulgaris and their hosts of origin (Sophora flavescens) effectively and their nodulation gene nodC was phylogenetically located in the symbiovar phaseoli. ©2015 IUMS.
Yan H.,China Agricultural University |
Yan H.,MOA Key Laboratory of Soil Microbiology |
Yan J.,Chinese Academy of Sciences |
Sui X.H.,China Agricultural University |
And 8 more authors.
International Journal of Systematic and Evolutionary Microbiology | Year: 2016
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 sequence comparisons. Results based upon concatenated sequence analysis of three housekeeping genes (recA, atpD and glnII, ≤ 93.8% similarities to known species) and average nucleotide identity (ANI) values of whole genome sequence comparisons (ranging 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 novel 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 Astragalus mongholicus, its original host legume. Strain CCBAU 23380T formed inefficient nodules on G. max, and it did not contain 18: 0, 18: 1ω7c 11-methyl or 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., is proposed, with CCBAU 23380T (=LMG 29231T =HAMBI 3645T) as the type strain. © 2016 IUMS.