- Volume 69, Issue 11, 2019

A Gram-stain-positive, aerobic, spore-forming, moderately halophilic bacterium, SSKP1-9T, was isolated from traditional salted shrimp paste (Ka-pi) produced in Samut Sakhon Province, Thailand. This strain grew optimally at 37–40 °C, pH 7.0 and in the presence of 8–16 % (w/v) NaCl. The 16S rRNA gene sequence similarity values between strain SSKP1-9T and Lentibacillus juripiscarius TISTR 1535T and Lentibacillus halophilus TISTR 1549T were 98.7 and 97.2 %, respectively. Based on 16S rRNA gene sequence similarity, strain SSKP1-9T represents a distinct novel species, as shown by phenotypic traits, DNA–DNA hybridization and average nucleotide identity values. In addition, the whole-cell protein profile confirmed the novelty of the taxon. The genomic DNA G+C content was 44.6 mol%. The major isoprenoid quinone was MK-7. The cell-wall peptidoglycan contained meso-diaminopimelic acid. Polar lipid analysis revealed the presence of phosphatidylglycerol, diphosphatidylglycerol, four unidentified lipids, an unidentified phospholipid and an unidentified glycolipid. The major cellular fatty acids were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0. The results of phenotypic and chemotaxonomic characteristics and whole-genome analysis support that strain SSKP1-9T represents a novel species of Lentibacillus , for which the name Lentibacilluslipolyticus sp. nov. is proposed. The type strain is SSKP1-9T (=JCM 32625T=TISTR 2597T).

In this work, the isolation and characterization of a novel anaerobic, mesophilic and cellulolytic bacterium is described. Comparative analysis of the almost-complete sequence of the 16S rRNA gene showed that the closest relatives were Hungateiclostridium straminisolvens CSK1T (97.53  %) and Hungateiclostridium thermocellum DSM 2360T (95.42  %). Due to physiological and phylogenetic differences from its closest relatives, a new species is proposed. Cells of N2K1T were observed to be rod-shaped, non-motile, spore-forming, Gram-stain-positive and able to adhere directly to cellulose fibre. Cellulolytic activity and optimal growth were observed at 45 °C and neutral pH (optimum, pH 7.5). Of all tested substrates, only filter paper (cellulose) and cellobiose were used for growth. Arabinose, fructose, glucose, lactose, mannitol, mannose, ribose, starch, sucrose, trehalose, xylan and xylose did not support growth. The main fermentation products were acetic acid and isopropanol. The major cellular fatty acids (>5 %) were C16 : 0iso, C16 : 0 DMA and C16 : 0. The type strain, N2K1T, was isolated from a mesophilically operated, lab-scale biogas fermenter fed with maize silage in Freising, Germany in 2017. The genome assembly of strain N2K1T is 4.04 Mbp with a DNA G+C content of 38.36 mol%. The name Hungateiclostridium mesophilum sp. nov. is proposed for the novel organism. Strain N2K1T (=DSM 107956T; =CECT 9704T) represents the type strain of Hungateiclostridium mesophilum sp. nov.

The present study was carried out to clarify the taxonomic relationship between two closely related Bacillus species, Bacillus okuhidensis Li et al. 2002 and Bacillus halodurans (ex Boyer 1973) Nielsen et al. 1995. The maximum-likelihood tree based on the 16S rRNA gene sequence and the phylogenomic tree based on concatenation of 16 protein-marker genes showed that these species were similar. Average nucleotide identity (ANIm 99.25 %, ANIb 98.2 %) and digital DNA–DNA hybridization values (93.5 %) between B. okuhidensis DSM 13666T and B. halodurans DSM 497T were greater than the threshold values for bacterial species delineation, indicating that they belong to the same species. Therefore, B. okuhidensis Li et al. 2002 should be reclassified as a later heterotypic synonym of B. halodurans (ex Boyer 1973) Nielsen et al. 1995.

The use of gnotobiotics has attracted wide interest in recent years due to technological advances that have revealed the importance of host-associated microbiomes for host physiology and health. One of the oldest and most important gnotobiotic mouse model, the altered Schaedler flora (ASF) has been used for several decades. ASF comprises eight different bacterial strains, which have been characterized to different extent, but only a few are available through public strain collections. Here, the isolation of a close relative of one of the less-studied ASF strains, Clostridium species ASF 502, from faeces of C57BL/6J mice is reported. Isolate TLL-A1T shares 99.5 % 16S rRNA gene sequence identity with Clostridium species ASF 502 and phylogenetic analyses indicate that both strains belong to the uncultured so-called ‘Lachnospiraceae UCG 006’ clade. The rare sugar d-arabinose was used as a sole carbon source in the anaerobic isolation medium. Results of growth experiments with TLL-A1T on different carbon sources and analysis of its ~6.5 Gb indicate that TLL-A1T harbours a large gene repertoire that enables it to utilize a variety of carbohydrates for growth. Comparative genome analyses of TLL-A1T and Clostridium species ASF 502 reveal differences in genome content between the two strains, in particular with regards to carbohydrate-activating enzymes. Based on genomic, molecular and phenotypic differences, we propose to classify strain TLL-A1T (DSM 106076T=KCTC 15657T) as a representative of a new genus and a new species, for which we propose the name Schaedlerella arabinosiphila gen. nov., sp. nov.

A Gram-stain-negative, non-motile, aerobic, short rod-shaped bacterium, designated OD32T, was isolated from a soil sample taken from the rhizosphere of Silene acaulis collected from the Arctic tundra. The novel strain, OD32T, was able to grow at 15–37 °C (optimum, 33 °C), pH 6.5–9.5 (pH 7.5–8.0) and 0–0.5 % NaCl (0 %, w/v). A phylogenetic analysis based on 16S rRNA gene sequences revealed that strain OD32T was most closely related to the genus Deinococcus ; it shared the highest sequence similarity (95.7 %) with Deinococcus grandis ATCC 43672T. Genomic DNA G+C content of the strain OD32T was 68.2 mol%. The predominant respiratory quinone was menaquinone 8 (MK-8). The major fatty acids were summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c), C15 : 1 ω6c, C17 : 1 ω6c, C17 : 0, C16 : 0 and iso-C17 : 0. Based on phylogenetic inference and genotypic characteristics, strain OD32T represents a novel species of the genus Deinococcus , for which the name Deinococcus arcticus sp. nov. is proposed. The type strain is OD32T (=KCTC 33972T=CICC 24671T).

Two isolates of heterotrophic, facultatively anaerobic, marine bacteria, designated DM1 and DM2T, were recovered from a lagoon sediment sample of Dongsha Island, Taiwan. Cells were Gram-reaction-negative rods. Nearly all of the cells were non-motile and non-flagellated during the late exponential to early stationary phase of growth, while a few of the cells exhibited motility with monotrichous flagellation. The two isolates required NaCl for growth and grew optimally at about 30 °C, 2–3 % NaCl and pH 7–8. They grew aerobically and could achieve anaerobic growth by fermenting d-glucose or other carbohydrates with production of acids and the gases, including CO2 and H2. Ubiquinone Q-8 was the only respiratory quinone. Cellular fatty acids were predominated by C16 : 0, C18 : 1ω7c and C16 : 1ω7c. The major polar lipid was phosphatidylethanolamine. Strains DM1 and DM2T had DNA G+C contents of 52.0 and 51.8 mol%, respectively, as determined by HPLC analysis. Phylogenetic analyses based on 16S rRNA gene sequences clearly indicated that the two isolates formed a distinct genus-level lineage in the family Aeromonadaceae of the class Gammaproteobacteria and was an outgroup with respect to a stable supragenic clade comprising species of the genera Oceanimonas , Oceanisphaera and Zobellella . The phylogenetic data and those from chemotaxonomic, physiological and morphological characterizations support the establishment of a novel species and genus inside the family Aeromonadaceae , for which the name Dongshaea marina gen. nov., sp. nov. is proposed. The type strain is DM2T (=BCRC 81069T=JCM 32096T).

Two strains (RW43-9T and RW17-10T) recovered from secondary treated wastewater from the Wastewater Treatment Plant (WWTP) in Reus (Spain) were characterized by a polyphasic taxonomic study, showing evidence that they represented two novel Arcobacter species. Based on the 16S rRNA gene for strain RW43-9T, the closest relative was Arcobacter butzleri LMG 10828T (99.9 % similarity), while for strain RW17-10T it was Arcobacter venerupis CECT 7836T (99.4 %). Additionally, multilocus phylogenetic analysis of five concatenated housekeeping genes (atpA, gyrA, gyrB, hsp60 and rpoB) showed that the two strains formed separate branches that are different from known Arcobacter species. Whole genome sequences of the two strains (RW43-9T and RW17-10T) were obtained and they were compared with those of the type strains of their nearest species. Using average nucleotide identity and in silico DNA–DNA hybridization gave values that were below 96 and 70 %, respectively. These results clearly confirm that they represent novel species. Additionally, the phenotypic characterization of the strains allowed their differentiation from other species. Therefore, the strains are proposed as representing two novel species with the names Arcobacter lacus sp. nov. (type strain RW43-9T=CECT 8994T=LMG 29062T) and Arcobacter caeni sp. nov. (type strain RW17-10T=CECT 9140T=LMG 29151T).

A beige-pigmented, Gram-stain-negative, aerobic, non-motile, rod-shaped bacterium, named 24T, was isolated from sludge of a pesticide manufacturing factory in Nantong, Jiangsu Province, China. 16S rRNA gene sequence analysis revealed that strain 24T shared highest similarity with Parapusillimonas granuli Ch07T (98.20 %), followed by Candidimonas nitroreducens SC-089T (98.07 %) and Paracandidimonas soli IMT-305T (98.03 %). Phylogenetic trees showed that strain 24T formed a distinct clade with Paracandidimonas soli IMT-305T. The results of DNA–DNA hybridization tests showed that reassociation values were less than 45 % with respect to these closely related type strains. Strain 24T contained Q-8 and putrescine as the major respiratory quinone and polyamine, respectively. The main cellular fatty acids were summed feature 3 (C16 : 1ω7c/C16 : 1ω6c), summed feature 2 (iso-C16 : 1 I/C14 0 3-OH/C12 : 0 aldehyde), summed feature 8 (C18 : 1ω7c/C18 : 1ω6c) and C12 : 0. The polar lipid profile included phosphatidylmethylethanolamin, phosphatidylethanolamine, phosphatidylglycerol, one unidentified phospholipid and one unidentified aminolipid. The G+C content was 56.83 mol%. Combined data from phenotypic, phylogenetic and DNA–DNA relatedness studies demonstrated that strain 24T represents a novel species of the genus Paracandidimonas , for which the name Paracandidimonas caeni sp. nov. is proposed. The type strain is 24T (=CCTCC AB 2018057T=KACC 19692T).

A Gram-stain-negative, aerobic, non-motile and rod-shaped bacterium, designated strain L4-6T, was isolated from an arable soil sample of tobacco in Huize, south-western China and subjected to polyphasic taxonomic characterization. The cells showed oxidase-positive and catalase-positive reactions. Growth occurred at 20–35 °C, at pH 5.0–8.0 and with 0–2 % (w/v) NaCl, optimally at 30 °C, pH 6.0–7.0 and 0–1 % (w/v) NaCl. The major respiratory lipoquinone was ubiquinone-8. The predominant cellular fatty acids (>10.0 %) were identified as summed feature 9 (iso-C17 : 1ω9c or C16 : 0 10-methyl), iso-C15 : 0 and iso-C17 : 0. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids, two unidentified aminophospholipids and five unidentified aminolipids. The genomic DNA G+C content was 60.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain L4-6T should be affiliated to the genus Dyella and formed a clade with the most closely related organism Dyella soli JS12-10T. 16S rRNA gene sequences similarity analysis showed that strain L4-6T was mostly closely related to D. soli JS12-10T (98.73 %) and Dyella lipolytica DHOB07T (98.02 %). DNA–DNA hybridization data indicated that strain L4-6T represented a novel genomic species belonging to the genus Dyella . The polyphasic taxonomic characteristics indicated that the strain L4-6T represents a novel species of the genus Dyella , for which the name Dyella tabacisoli sp. nov. (type strain L4-6T=CGMCC 1.16273T=KCTC 62035T) is proposed.

Twenty-two cream-coloured bacterial strains were isolated from oak trees affected by acute oak decline (AOD) in Southern England. Isolates were Gram-negative, motile, slightly curved rods, aerobic, non-spore-forming, catalase positive and oxidase positive. 16S rRNA gene sequence analysis placed the strains in two separate phylogenetic clusters in the Pseudomonas straminea group, with Pseudomonas flavescens as the closest phylogenetic relative. Multilocus sequence analyses of the gyrB, rpoD and rpoB genes supported the delineation of the strains into two separate taxa, which could be differentiated phenotypically and chemotaxonomically from each other, and their closest relatives. Average nucleotide identity and in silico DNA–DNA hybridization values revealed percentages of genome similarity below the species threshold (95 and 70 %, respectively) between the two taxa and the closest relatives, confirming their novel species status. Therefore, on the basis of this polyphasic approach we propose two novel Pseudomonas species, Pseudomonas daroniae sp. nov. (type strain FRB 228T=LMG 31087T=NCPPB 4672T) and Pseudomonas dryadis sp. nov. (type strain FRB 230T=LMG 31087T=NCPPB 4673T).

A Gram-negative, aerobic, rod-shaped, non-spore-forming bacterium, designated as strain BML3T, was isolated from a sputum sample of a hospital patient in Japan. Strain BML3T grew at temperatures from 4 to 40 °C, in 1.0–7.0 % (w/v) NaCl and at pH 6.0–9.0. Results of phylogenetic analysis based on the sequences of housekeeping genes, including the 16S rRNA gene and rpoB, rpoD and gyrB, showed that strain BML3T was part of the Pseudomonas putida group and located close to Pseudomonas asiatica , Pseudomonas monteilii and P. putida . Whole-genome comparisons, using average nucleotide identity and digital DNA–DNA hybridization, confirmed strain BML3T to be a distinct species among the P. putida group. Phenotypic characterization tests demonstrated that the utilization of phenylmercuric acetate could distinguish this strain from other closed species of the P. putida group. Based on genetic and phenotypic evidence, strain BML3T should be classified as a novel species, for which the name Pseudomonas juntendi sp. nov. is proposed. The type strain is BML3T (=DSM 109244T,=JCM 33395T), with a DNA G+C content of 62.66 mol %.

Strains A31/70T, CCUG 58779 and SD129 were Gram-stain-negative, short rods, motile by one polar flagellum and isolated from clinical specimens in Botswana, Sweden and Spain, respectively. The 16S rRNA sequence similarity values grouped them in the Pseudomonas stutzeri phylogenetic group of species. The DNA G+C content ranged from 65.5 to 65.7 mol%. The strains were characterized phenotypically by the API 20NE and Biolog GEN III tests, and chemotaxonomically by their whole-cell MALDI-TOF MS protein profiles and by their fatty acid contents. The absence of the arginine dihydrolase and the hydrolysis of gelatin differentiated these strains from the closest species, Pseudomonas azotifigens . The major fatty acid contents were summed feature 8 (38.6 %), C16 : 0 (22.6 %), summed feature 3 (20.5 %) and C12 : 0 (8.4 %). Multilocus sequence analysis with three housekeeping gene sequences (rpoD, gyrB and 16S rRNA) together with whole-genome comparisons indicated that these strains cluster together in the phylogenetic analysis and their similarity values were lower than the thresholds established for species in the genus Pseudomonas . These results permit us to conclude that strains A31/70T, CCUG 58779 and SD129 belong to a novel species in the genus Pseudomonas for which the name Pseudomonas nosocomialis sp. nov. is proposed. The type strain is A31/70T (=CECT 9981T=CCUG 73638T).

A white-coloured, Gram-stain-negative, aerobic, rod-shaped bacterium (designated strain SY21T) was isolated from waste-activated sludge. Optimal growth occurred at 28 °C and pH 7.0. Phylogenetic analysis based on the 16S rRNA gene sequences showed that strain SY21T exhibited 16S rRNA gene sequence similarities of 95.5–98.0 % to Thermomonas species and clustered with the type species of the genus Thermomonas . In strain SY21T, the predominant respiratory quinone was ubiquinone Q-8, and the cellular fatty acids consisted mainly of iso-C15 : 0, C16 : 0, iso-C11 : 0 3-OH, summed feature 3 and summed feature 9. The major polar lipids were phosphatidylcholine, phosphatidylglycerol and phosphatidylethanolamine. The genomic DNA G+C content was determined to be 67.9 mol% and the DNA–DNA relatedness between strain SY21T and the closest phylogenetically related strain, Thermomonas carbonis KCTC 42013T, was 35.0±0.1 %. Based on the distinct phenotypic, chemotaxonomic and phylogenetic properties, strain SY21T represents a novel species of the genus Thermomonas , for which the name Thermomonas aquatica sp. nov. is proposed. The type strain is SY21T (=KCTC 62191T=NBRC 113114T).

Strain CECT 7735T, a marine Gram-reaction negative, aerobic, non-motile bacterium, was isolated from coastal seawater in Valencia, Spain. Strain CECT 7735T is chemoorganotrophic, mesophilic, slightly halophilic, grows at 15–28 °C but not at 4 or 37 °C, requires seawater for growth and grows up to 6 % salinity. The major cellular fatty acid is summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The G+C content of the genome is 55.7 mol%. Comparative analysis of the 16S rRNA gene sequence shows the strain is affiliated to the family Rhodobacteraceae , in the class Alphaproteobacteria , with highest similarities to Phaeobacter species (97.0–97.5 %), Shimia species (96.5–97.3 %) and Pseudopelagicola gijangensis (96.5 %). Further phylogenomic analysis through the up-to-date-bacterial core gene (UBCG) set showed P. gijangensis to be its closest relative. Average nucleotide identity and in silico DNA–DNA hybridization values are lower than 85 and 21 %, respectively, with its phylogenetic relatives, suggesting that strain CECT 7735T represents a new species. The average amino acid identity value was over 70 % with the genome of the type strain of P. gijangensis and with all those of Shimia species. These values, together with UBCG set trees, suggest that the new species and P. gijangensis belong to the same genus and that Pseudopelagicola should be reclassified as a Shimia species. We conclude that strain CECT 7735T represents a new species in the genus Shimia , for which we propose the name Shimia thalassica sp. nov. In addition, Pseudopelagicola gijangensis is reclassified as Shimia gijangensis comb. nov. From the same phylogenomic study, it can be concluded that Thalassobius activus should be reclassified in the genus Cognatishimia as Cognatishimia activa comb. nov.

A Gram-negative bacterium, namely strain ANRC-JHZ47T, was isolated from a seawater sample collected at Biological Bay, Fildes Peninsula, Antarctica. Cells of strain ANRC-JHZ47T were rod-shaped and motile by a single polar flagellum. Strain ANRC-JHZ47T was aerobic, oxidase-negative, and catalase-positive. The strain grew at 4–37 °C (optimum, 25 °C), pH at 3.5–10.0 (optimum, pH 5.5) and in NaCl at 1–7.0 % (w/v; optimum, 2–3 %). Strain ANRC-JHZ47T used Q-8 as the predominant respiratory quinone. Its predominant fatty acids were C16 : 0 (21.9 %), C12 : 0 (12.6 %), C19 : 0cyclo ω8c (12.4 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c; 13.1 %), C10 : 0 3-OH (11.3 %) and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c; 6.0 %). Its major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, one unidentified aminolipid and five unknown polar lipids. The DNA G+C content was 42.6 mol%. Strain ANRC-JHZ47T showed the highest 16S rRNA gene sequence similarity to Marinomonas arenicola KMM 3893T (97.9 %), followed by Marinomonas primoryensis KMM 3633T (97.6 %), Marinomonas profundimaris D104T (97.2 %) and Marinomonas pollencensis IVIA-Po-185T (97.0 %). Furthermore, the average nucleotide identity values between strain ANRC-JHZ47T and M. arenicola KMM 3893T, M. primoryensis KMM 3633T and M. profundimaris D104T were 79.8, 74.0, and 74.1 %, respectively. The in silico DNA–DNA hybridization values between them were 22.5±2.5, 20.4±2.3 and 19.9±2.3 %, respectively. Based on the results of phenotypic and phylogenetic analyses, strain ANRC-JHZ47T is considered to represent a novel species of the genus Marinomonas , for which the name Marinomonas flavescens sp. nov. is proposed. The type strain is ANRC-JHZ47T (=MCCC 1K03604T=KCTC 72113T).

A novel Gram-stain-negative, aerobic, non-motile and rod-shaped bacterium was isolated from Lake Dajiaco on the Tibetan Plateau. Strain DJCT grew without NaCl and tolerated up to 3 % (w/v) NaCl. Growth occurred at pH 6.0–10.0 (optimum, pH 7.0–8.0) and 15–37 °C (optimum, 25–30 °C). Vitamins were not required for growth. The main polar lipids of strain DJCT were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The predominant respiratory quinone was Q-10. The major fatty acid was C18 : 1ω7c. Genome sequencing revealed a genome size of 4.61 Mbp and a G+C content of 62.9 mol%. Analysis of 16S rRNA sequences showed that strain DJCT belonged to the genus Tabrizicola , with the closest neighbour Tabrizicola aquatica RCRI19T (97.5 %). DNA–DNA relatedness between strain DJCT and the closest phylogenetically related strain T. aquatica RCRI19T was 40.8 %. Stain DJCT was clearly distinguished from the type strain mentioned above through phylogenetic analysis, DNA–DNA hybridization, fatty acid composition data and a range of physiological and biochemical characteristic comparisons. Based on its phenotypic and chemotaxonomic characteristics, strain DJCT could be classified as a representative of a novel species of the genus for which the name Tabrizicola alkalilacus sp. nov. is proposed. The type strain is DJCT (=CICC 24242T=KCTC 62173T).

A Gram-stain-negative bacterial strain, designated JW-3T, was isolated from a soil sample collected from farmland in Yantai, Shandong Province, PR China. Cells of strain JW-3T are motile rods and strictly aerobic, showing catalase- and oxidase-positive reactions. Strain JW-3T could grow at 16–37 °C (optimum, 30 °C), at pH 6.0–9.0 (pH 7.0) and in the presence of 0–1 % (w/v) NaCl (0.5 %, in Luria–Bertani broth). The major fatty acids were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c; 35.5 %), iso-C16 : 0 (16.7 %) and C12 : 0 (10.8 %). The major respiratory quinone was ubiquinone-8 (Q8). The polar lipids of strain JW-3T consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, four unidentified phospholipids, two unidentified lipids, two unidentified glycolipids and a partial unidentified aminophospholipid. Strain JW-3T was most closely related to Steroidobacter agariperforans KA5-BT with 97.67 % 16S rRNA gene sequence similarity. Results of phylogenetic analyses, based on 16S rRNA gene sequencing, showed that strain JW-3T forms a distinct phylogenic lineage within the genus Steroidobacter of the family Sinobacteraceae . The DNA G+C content of strain JW-3T was 62.57 mol%, based on its draft genome sequence. Average nucleotide identity values and digital DNA–DNA hybridization values for draft genomes, between strain JW-3T and strain KA5-BT, were 84.54 and 30.80 %, respectively. Based on its phenotypic, chemotaxonomic and molecular features, and DNA–DNA hybridization results, strain JW-3T represents a novel species of the genus Steroidobacter , for which the name Steroidobacter soli sp. nov. is proposed. The type strain is JW-3T (=CCTCC AB 2018184T=KCTC 62820T).

Information about the symbionts of legumes of the Caesalpinioideae subfamily is still limited, and we performed a polyphasic approach with three Bradyrhizobium strains—CNPSo 3448T, CNPSo 3394 and CNPSo 3442—isolated from Chamaecrista fasciculata, a native legume broadly distributed in the USA. In the phylogenetic analysis of both the 16S rRNA gene and the intergenic transcribed spacer, the CNPSo strains were clustered within the Bradyrhizobium japonicum superclade. Multilocus sequence analysis with six housekeeping genes—glnII, gyrB, recA, rpoB, atpD and dnaK—indicated that Bradyrhizobium diazoefficiens is the closest species, with 83 % of nucleotide identity. In the genome analyses of CNPSo 3448T, average nucleotide identity and digital DNA–DNA hybridization results confirmed higher similarity with B. diazoefficiens , with values estimated of 93.35 and 51.50 %, respectively, both below the threshold of the same species, confirming that the CNPSo strains represent a new lineage. BOX-PCR profiles indicated high intraspecific genetic diversity between the CNPSo strains. In the analyses of the symbiotic genes nodC and nifH the CNPSo strains were clustered with Bradyrhizobium arachidis , Bradyrhizobium forestalis, Bradyrhizobium cajani , Bradyrhizobium kavangense and Bradyrhizobium vignae , indicating a different phylogenetic history compared to the conserved core genes. Other physiological (C utilization, tolerance to antibiotics and abiotic stresses), chemical (fatty acid profile) and symbiotic (nodulation host range) properties were evaluated and are described. The data from our study support the description of the CNPSo strains as the novel species Bradyrhizobium niftali sp. nov., with CNPSo 3448T (=USDA 10051T=U687T=CL 40T) designated as the type strain.

A Gram-stain-negative, aerobic and non-motile strain, designated 18x22-1T, was isolated from a forest soil sample collected from Limushan Nature Reserve in Hainan Province, PR China. Growth occurred at 15–37 °C and pH 6.0–8.0 without NaCl. The 16S rRNA gene sequence analyses showed that strain 18x22-1T was closely related to Ramlibacter tataouinensis DSM 14655T (98.5 %), followed by Ramlibacter henchirensis DSM 14656T (97.9 %) and other Ramlibacter species and formed a stable cluster with R. tataouinensis DSM 14655T, R. henchirensis DSM 14656T, Ramlibacter solisilvae JCM 19319T and Ramlibacter rhizophilus CCTCC AB 2015357T. Results of chemotaxonomic analyses showed that ubiquinone-8 (Q-8) was the major respiratory quinone, and the major fatty acids (>10 % of the total amounts) were C16 : 0 and C17 : 0cyclo. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, two unidentified aminopholipids and four unidentified phospholipids. The draft genome sequence was 4.47 Mb long with a G+C content of 68.9 mol%. The average nucleotide identity and digital DNA–DNA hybridization values between strain 18x22-1T and four closely related type strains were in the range of 79.3–82.3 % and 21.9–25.1 %, respectively. The results of phenotypic, phylogenetic and chemotaxonomic analyses supported that strain 18x22-1T represents a novel species of the genus Ramlibacter , for which the name Ramlibacter humi sp. nov. is proposed. The type strain is 18x22-1T (=GDMCC 1.1584T=KCTC 52922T).