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A novel bifidobacterium (designated F753-1 T ) was isolated from the gut of honeybee ( Apis mellifera ). Strain F753-1 T was characterized using a polyphasic taxonomic approach. Strain F753-1 T was phylogenetically related to the type strains of Bifidobacterium mizhiensis , Bifidobacterium asteroides , Bifidobacterium choladohabitans , Bifidobacterium mellis , Bifidobacterium apousia and Bifidobacterium polysaccharolyticum , having 98.4-99.8 % 16S rRNA gene sequence similarities. The phylogenomic tree indicated that strain F753-1 T was most closely related to the type strains of B. mellis and B. choladohabitans . Strain F753-1 T had the highest average nucleotide identity (94.1-94.5 %) and digital DNA-DNA hybridization (56.3 %) values with B. mellis Bin7N T . Acid production from amygdalin, d-fructose, gentiobiose, d-mannose, maltose, sucrose and d-xylose, activity of α -galactosidase, pyruvate utilization and hydrolysis of hippurate could differentiate strain F753-1 T from B. mellis CCUG 66113 T and B. choladohabitans JCM 34586 T . Based upon the data obtained in the present study, a novel species, Bifidobacterium apis sp. nov., is proposed, and the type strain is F753-1 T (=CCTCC AB 2023227 T =JCM 36562 T =LMG 33388 T ).

Lentilactobacillus rapi subsp. dabitei was proposed by Li et al . in 2022. The type strains of L. rapi subsp. dabitei and L. rapi subsp. rapi shared 93.1 % average nucleotide identity and 52.8 % digital DNA-DNA hybridization values. Strain IMAU80584 T was proposed as a novel subspecies of L. rapi rather than a novel species of the genus Lentilactobacillus on the basis of similar phenotypic characteristics (including growth temperature and pH, tolerance to NaCl and features based on API 50CH and API ZYM). However, the phenotypic investigation performed by Li et al. was insufficient because some physiological and biochemical characteristics recommended by Mattarelli et al. were not included. In the present study, the taxonomic relationship between L. rapi subsp. dabitei and L. rapi subsp. rapi was re-evaluated. Based upon the data obtained in the present study, we propose to elevate L. rapi subsp. dabitei to the species level as Lentilactobacillus dabitei sp. nov. The type strain is IMAU80584 T (=GDMCC 1.2566 T =JCM 34647 T ).

Six strains were isolated from root nodules of Vicia faba grown in Nanchang, Yifeng, Taihu, Huaibei, Bengbu and Lujiang, in the middle and lower reaches of the Yangtze River. According to phylogenetic analyses of 16S rRNA gene, atpD and recA sequences, these strains belong to the genus Rhizobium, with Rhizobium etli and Rhizobium leguminosarum as the closest related species. CCBAU 33202(T), a representative of these novel isolates, showed sequence similarity to its closest relatives R. etli CFN 42(T) and R. leguminosarum USDA 2370(T) of 99.5 and 99.1 % for the 16S rRNA gene, 91.9 and 91.9 % for atpD and 90.3 and 93.2 % for recA. The strains from this study could also be differentiated from R. etli CFN 42(T) and R. leguminosarum USDA 2370(T) by 16S-IGS RFLP and SDS-PAGE of whole-cell proteins, fatty acid profiles and several phenotypic characteristics. DNA-DNA hybridization yielded relatedness of 19 and 14-43 %, respectively, with R. etli CFN 42(T) and strains representing different biovars of R. leguminosarum. All data obtained in this study showed that these V. faba isolates belong to a novel species, for which the name Rhizobium fabae sp. nov. is proposed. The type strain, CCBAU 33202(T) (=LMG 23997(T) =JCM 14381(T)), was isolated from Nanchang.

Thirty-one rhizobial strains isolated from nodules of legumes native of Xinjiang, China, were characterized. These strains were classified as belonging to the genus Rhizobium based on amplified 16S rDNA restriction analysis (ARDRA). The strains were distinguished from recognized Rhizobium species using analysis of 16S-23S rDNA intergenic spacers (IGS-RFLP), SDS-PAGE analysis of whole proteins and BOX-PCR; the test strains always formed a distinct cluster with patterns that were quite different from those of the reference rhizobial strains used. According to the phylogenetic analysis based on the 16S rRNA gene, the test strains belonged to the genus Rhizobium, with Rhizobium tropici, Rhizobium rhizogenes and Rhizobium lusitanum as the closest related species, with 99.6, 99.2 and 99.4 % sequence similarities, respectively, between the type strains of the three Rhizobium species and strain CCBAU 83401(T). Phylogenetic analyses of the representative strains using IGS and atpD, recA and glnII genes all confirmed the phylogenetic arrangements obtained using the 16S rRNA gene. The DNA-DNA relatedness values between strain CCBAU 83401(T) and strains CCBAU 83364, CCBAU 83345 and CCBAU 83523 ranged from 80.8 to 100 %, showing that they belong to the same species. The DNA-DNA relatedness between strain CCBAU 83401(T) and R. tropici IIB CIAT 899(T), R. tropici IIA CFN 299, R. rhizogenes LMG 150(T) and R. lusitanum P1-7(T) were 26.9, 27.7, 38.2 and 22.6 %, respectively, clearly indicating that strain CCBAU 83401(T) represents a novel species. Phenotypic characterization of four representative strains, CCBAU 83401(T), CCBAU 83364, CCBAU 83345 and CCBAU 83523, showed several distinctive features that differentiated them from closely related species. The 31 strains had identical nodD and nifH genes, which were very similar to those of the bean-nodulating R. lusitanum, Devosia neptuniae and R. tropici IIB. Based upon these results, the strains from this study are considered to represent a novel species, for which the name Rhizobium multihospitium sp. nov. is proposed. The DNA G+C content ranged from 65.3 to 66.0 mol% (T(m)). The type strain is CCBAU 83401(T) (=LMG 23946(T)=HAMBI 2975(T)), which nodulates Robinia pseudoacacia, but not Leucaena leucocephala, Phaseolus vulgaris, Pisum sativum or Medicago sativa.

Seventeen strains of lespedeza rhizobia, a previously defined novel group, were further characterized by comparison with phylogenetically related species using a polyphasic approach, including SDS-PAGE of whole-cell proteins, PCR-based restriction fragment length polymorphism analysis of ribosomal intergenic spacer sequences, determination of DNA G+C contents, DNA-DNA hybridization and analysis of phenotypic features. Based on data obtained in the present and previous studies, a novel species, Rhizobium miluonense sp. nov., is proposed for these strains. The type strain of R. miluonense is CCBAU 41251(T) (=LMG 24208(T)=HAMBI 2971(T)). Strain CCBAU 41251(T) could form ineffective nodules on Phaseolus vulgaris in addition to its original host Lespedeza chinensis.