- Volume 75, Issue 7, 2025

Four actinobacterial strains, designated NEAU-PBA1T, NEAU-PB14, NEAU-PB65 and NEAU-PB77, were isolated from the frass of Protaetia brevitarsis collected from Harbin, Heilongjiang Province, China. These strains were Gram-stain positive, aerobic and produced branched substrate mycelium and aerial hyphae, without producing diffusible pigments in the tested media. Upon maturity, spore chains formed on the aerial hyphae, while the mycelium fragmented with age. The genome sizes of these four strains ranged from 7.41 to 7.49 Mbp, with the genomic DNA G+C content varying from 71.8% to 72.9%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that these four strains belonged to the genus Nocardiopsis and exhibited high sequence similarity with Nocardiopsis changdeensis Mg02T. The average nucleotide identity and digital DNA–DNA hybridization values between these four isolates exceeded the threshold for species delineation, while the values between the four isolates and their close relatives were below the threshold. The predominant menaquinones in strain NEAU-PBA1T are MK-10 (H4, H6, H8) and MK-10, while the phospholipids included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphoglycolipid, phosphatidylcholine, one phospholipid and one lipid. The major cellular fatty acids comprised anteiso-C15:0, iso-C16:0, anteiso-C17: 0 and C18:1  ω9c. Based on polyphasic taxonomic analysis, strains NEAU-PBA1T, NEAU-PB14, NEAU-PB65 and NEAU-PB77 were identified as a novel species within the genus Nocardiopsis, and the name Nocardiopsis protaetiae sp. nov. was proposed. The type strain is NEAU-PBA1T (=MCCC 1K08877T=JCM 37021T).

Twelve strains of a novel Corynebacterium species were cultured from human respiratory samples collected in the USA and Botswana. Five strains underwent detailed phenotypic and chemotaxonomic characterization, while all 12 strains were included in phylogenomic analyses. Optimal growth was observed on brain heart infusion solid medium and in liquid media, including brain heart infusion and tryptic soy broth when supplemented with Tween 80, a source of the fatty acid oleic acid. Cells were Gram-positive, non-spore-forming, non-motile bacilli that exhibited catalase activity but lacked oxidase activity. Major fatty acids were 18 : 1 ω9c (oleic acid) and 16 : 0 (palmitic acid). Analysis of 16S ribosomal RNA gene sequences identified these strains as belonging to the genus Corynebacterium (family Corynebacteriaceae), with the closest relatives being Corynebacterium accolens and Corynebacterium macginleyi. Whole-genome sequencing revealed that the genomes are 2.47–2.62 Mbp in size and have a G+C content of 58.7–59.0 mol%. Average nucleotide identity and in silico DNA–DNA hybridization values for comparisons of these genomes to those of closely related phylogenetic neighbours were 93.19–93.62% and 19.9–36.3%, respectively. These results indicate that these strains represent a novel species of Corynebacterium, for which we propose the name Corynebacterium rhinophilum sp. nov., with the type strain MSK072T (=DSM 118652T=JCM 37534T).

Six aerobic, Gram-stain-positive, non-motile, rod-shaped bacterial strains (P13T, P18, P16T, P17, P20T and P15) were isolated from the intestinal contents of the plateau vole (Neodon fuscus) collected from the Qinghai–Tibet Plateau, PR China. Phylogenetic analyses showed that these isolates formed three well-separated lineages in all phylogenetic and phylogenomic trees comprising members of the genus Herbiconiux. The average nucleotide identity and digital DNA–DNA hybridization values between the three novel type strains (P13T/P16T/P20T) and other known species in this genus were all below the thresholds of 95–96% and 70%. Analysis of fatty acid profiles showed anteiso-C15:0 and anteiso-C17:0 as the major fatty acids for all six strains. All novel type strains had diphosphatidylglycerol, phosphatidylglycerol and unidentified glycolipids 2 as the major polar lipids. The peptidoglycan amino acids of these three type strains consisted of alanine, glutamic acid, glycine and 2,4-diaminobutyric acid. All novel type strains had MK-11 and MK-10 as the predominant respiratory quinone. The DNA G+C contents of strains P13T, P16T and P20T were 70.0, 69.0 and 70.0 mol%, respectively. Based on genotypic, phenotypic, phylogenetic and biochemical properties, the six novel strains represent three novel species in the genus Herbiconiux, for which the names Herbiconiux liangxiaofengii sp. nov. (type strain P13T=GDMCC 1.4677T=JCM 37540T), Herbiconiux wuyangfengii sp. nov. (type strain P16T=GDMCC 1.4678T=JCM 37541T) and Herbiconiux liukaitaii sp. nov. (type strain P20T=GDMCC 1.4681T=JCM 37542T) are proposed, respectively.

Strain KLBMP 9127T, isolated from dolomite weathering crusts, was subjected to comprehensive taxonomic characterization using a polyphasic taxonomic approach. Strain KLBMP 9127T is an aerobic, Gram-stain-positive bacterium with coccoid to short rod-shaped cells that forms stromal mycelia and spherical sporangia. This Gram-positive strain exhibits chemotaxonomic features characteristic of the genus. The genus Streptosporangium is characterized by the presence of meso-diaminopimelic acid and madurose in whole-organism hydrolysates, and menaquinones MK-9(H2) and MK-9(H4) are the predominant respiratory quinones. The predominant fatty acid (>10%) of strain KLBMP 9127T was identified as C13 : 0 (17.6%) and C17 : 0 10-methyl (22.3%). Phylogenetic analysis based on 16S rRNA gene sequences revealed that KLBMP 9127T forms a distinct lineage within the Streptosporangium clade, showing 97.2% sequence similarity with its closest relative, Streptosporangium longisporum DSM 43180T. Genomic comparisons of KLBMP 9127T demonstrated digital DNA–DNA hybridization (dDDH) and average nt identity (ANI) values of 24.1% and 81%, respectively, both falling below the recommended thresholds for species demarcation (dDDH≥70%; ANI≥95–96%). Comprehensive phenotypic profiling (cell wall composition, menaquinone profiles and fatty acid methyl esters) and genomic evidence conclusively distinguish KLBMP 9127T from related taxa. Based on these cumulative findings, strain KLBMP 9127T was proposed as the type strain of a novel species, Streptosporangium soli sp. nov., with the designation KLBMP 9127T (=CGMCC 4.7739T=NBRC 115834T). Genomic analysis identified 23 biosynthetic gene clusters encoding specialized metabolites, including polyketide synthases, nonribosomal peptide synthetases and enediyne-type antitumour compound pathways. In antitumour proliferation experiments, within the tested concentration range of 5–200 µg ml−1, the inhibition rate gradually increased from 13.7% (at 5 µg ml−1) to 99.1% (at 200 µg ml−1). This extensive biosynthetic potential highlights the strain’s significant capacity for producing novel antibiotics and antineoplastic agents, underscoring the biotechnological importance of this genus in natural product discovery.

Three novel actinobacterial strains, H27-S2T, H34-AA3 and H34-S5, were isolated from soil samples collected on Horseshoe Island, Antarctica, as part of an effort to discover new Streptomyces species with industrial and pharmaceutical relevance. A genome-based comparative analysis was conducted to characterize the strains. The pairwise comparisons of the 16S rRNA gene sequences confirmed their affiliation with the genus Streptomyces, with the highest sequence identity values of 99.7–99.8% with Streptomyces avidinii NBRC 13429T. However, genome-based taxonomic analyses, including digital DNA–DNA hybridization and average nucleotide identity analyses, confirmed that these strains represent a novel species within the genus Streptomyces. A comprehensive genome annotation revealed that the strains possess extensive biosynthetic capabilities, particularly for secondary metabolites, antimicrobial resistance mechanisms, heavy metal resistance genes and stress adaptation systems for survival in cold environments. Their metabolic potential includes aromatic compound degradation, indicating a promising role in bioremediation, while their secondary metabolite gene clusters suggest potential applications in pharmaceutical and clinical research. Given their ability to thrive in extreme Antarctic conditions, these strains may contribute to advancements in cryotechnology and enzyme production for industrial applications. Based on phylogenomic analyses, these strains represent a novel Streptomyces species, for which the name Streptomyces antarcticus sp. nov. is proposed. The type strain is H27-S2T (=DSM 114983T=CGMCC 4.7867T).

An anaerobic, thermophilic methanogen, designated strain LWZ-6T, was isolated from the Shengli oil field, China. The cells of strain LWZ-6T were non-motile cocci, with a diameter of 0.5–1.0 µm, and formed aggregates. They reduced methanol and monomethylamine into methane, using H2 as an electron donor. Dimethylamine, trimethylamine and methanethiol, H2/CO2, formate, acetate, pyruvate, lactate and glucose were not used as energy sources. Strain LWZ-6T required yeast extract, acetate or CO2 as carbon sources. Strain LWZ-6T grew at 35–65 °C (optimum 55 °C), pH 5.0–8.0 (optimum 6.0–6.5) and 0–60 g l−1 NaCl (optimum 9 g l−1). The genome was 1.54 Mbp with a G+C content of 54.42 mol%. Strain LWZ-6T shared 83.54% 16S rRNA gene sequence identity with Infirmifilum lucidum strain 3507LTT in the class Thermoprotei. Phylogenetic analysis based on the 16S rRNA gene, along with phylogenomic analysis, indicated that strain LWZ-6T belonged to the candidate class ‘Candidatus Methanomethylicia’, which lacks cultivated representatives. Based on these findings, a new species within a new genus, Methanosuratincola petrocarbonis gen. nov., sp. nov., is proposed for LWZ-6T (=CCAM 1872T=JCM 39528T). In addition, we propose the Methanosuratincolia class. nov. for candidate class ‘Ca. Methanomethylicia’ represented by Methanosuratincolaceae fam. nov. and Methanosuratincolales ord. nov. within the phylum Thermoproteota.

Three Gram-negative, facultatively anaerobic, rod-shaped, non-motile and reddish-pigmented bacterial strains, designated GW2-5T, WM1T and Tmos10T, were isolated from distinct environments in the Republic of Korea. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the three strains belonged to the genus Fibrella. The type strain GW2-5ᵀ grew at temperatures of 10–35 °C (optimum: 25 °C), pH levels of 6.0–12.0 (optimum: pH 7.0) and NaCl concentrations of 0–0.5% (optimum: 0%). Strain WM1ᵀ grew at temperatures of 10–37 °C (optimum: 30 °C), pH levels of 5.0–12.0 (optimum: pH 7.0) and NaCl concentrations of 0–1% (optimum: 0%). Strain Tmos10ᵀ grew at temperatures of 10–35 °C (optimum: 25 °C), pH levels of 5.0–12.0 (optimum: pH 7.0) and NaCl concentrations of 0–0.5% (optimum: 0%). The three strains exhibited the highest 16S rRNA gene sequence similarity to Fibrella forsythiae HMF5405ᵀ (98.7%) for strain GW2-5ᵀ, Fibrella aestuarina BUZ 2ᵀ (98.7%) for strain WM1ᵀ and Fibrella forsythiae HMF5405ᵀ (96.6%) for strain Tmos10ᵀ. The average nucleotide identity values ranged from 73.5% to 86.6%, while the digital DNA–DNA hybridization values ranged from 19.5% to 31.4% between the three novel isolates and species belonging to the genus Fibrella. Based on phenotypic, physiological, biochemical, genomic and phylogenetic characteristics, strains GW2-5T, WM1T and Tmos10T are proposed as novel species within the genus Fibrella. They are designated as Fibrella aquatica sp. nov. (type strain GW2-5T=KACC 23817T=TBRC 19128T), Fibrella musci sp. nov. (type strain WM1T=KACC 23815T=TBRC 19127T) and Fibrella arboris sp. nov. (type strain Tmos10T=KACC 23816T=TBRC 19129T), respectively.

Four novel strain pairs (ZJ93T/ZJ100, ZJ151T/ZJ99, ZJ1593T/ZJ373 and H31T/H49) were isolated from the respiratory tracts of marmots and the faeces of white-lipped deer. All eight isolates were facultatively anaerobic, oxidase- and catalase-negative, non-spore-forming, non-motile and Gram-stain-positive cocci in short and long chains. Analyses of the 16S rRNA gene and genome sequences revealed that the eight strains represent four novel species of the genus Streptococcus. The 16S rRNA gene sequence analysis showed that strain ZJ93T had the highest similarity to Streptococcus marmotae HTS5T (98.23%), ZJ151T to Streptococcus halotolerans HTS9T (98.18%), ZJ1593T to Streptococcus criceti HS-6T (96.77%) and H31T to Streptococcus pantholopis TA 26T (98.25%). The values of digital DNA–DNA hybridization between the four novel species and their phylogenetically related type strains of the genus Streptococcus were far below 70%, but higher than 70% within each pair of novel strains (ZJ93T/ZJ100, ZJ151T/ZJ99, ZJ1593T/ZJ373 and H31T/H49). The DNA G+C contents of ZJ93T, ZJ151T, ZJ1593T and H31T were 41.0, 39.0, 41.5 and 41.5 mol%, respectively. The main cellular fatty acid of all eight strains was C16 : 0. Based on the results from the aforementioned analyses, the eight novel strains were classified as representing four novel species of genus Streptococcus, for which the names Streptococcus handemini sp. nov. [type strain ZJ93T (=GDMCC 1.3112T=JCM 35325T)], Streptococcus jiangjianxini sp. nov. [type strain ZJ151T (=GDMCC 1.3116T=JCM 35326T)], Streptococcus tangpeifui sp. nov. [type strain ZJ1593T (=GDMCC 1.3115T=JCM 35327T)] and Streptococcus huangxiaojuni sp. nov. [type strain H31T (=GDMCC 1.4758T=JCM 37397T)] are proposed, respectively.

Nine Gram-positive, non-motile, facultatively anaerobic cocci, designated EM39Eᵀ, JEK85, 18KM676, 21M1142, 18KM445T, 18KM444, 18KM245, 18KM583 and 21KM1573, were isolated from diverse animal material, including horse and pig skin, bovine mastitis milk and feline urine from a urinary tract infection. Phylogenomic analysis based on amino-acid alignment obtained from translated whole-genome sequences; digital DNA–DNA hybridization (dDDH); 16S rRNA, dnaJ, hsp60, rpoB and sodA gene comparison; and MALDI-TOF MS spectral profiles placed the strains within the Macrococcus caseolyticus clade. They were closely related to Macrococcus bohemicus CCM 7100ᵀ, Macrococcus epidermidis CCM 7099ᵀ, Macrococcus goetzii CCM 4927ᵀ and Macrococcus capreoli DSM 113939T. The novel species exhibited 22.30% dDDH and 79.49% average nucleotide identity (ANI) to each other, <24% dDDH and <82% ANI to their closest relatives, values below established species delineation thresholds, confirming their classification as two distinct novel species. Chemotaxonomic analysis identified, in both species, diphosphatidylglycerol, phosphatidylglycerol, aminolipid, glycolipids and phosphoglycolipids, as the major polar lipids. Fatty acid profiling revealed C14 : 0, C16 : 1 ω11c, C16 : 0 and C18 : 1 ω13c as predominant components, with antesio-C15 : 0 in one species. The peptidoglycan type was A3α l-Lys–Gly2. The novel species can be distinguished from their closest relatives by their ability to grow in 12.5% NaCl. EM39Eᵀ, JEK85, 18KM676 and 21M1142 can be distinguished by positive reaction to d-ribose, and 18KM445T, 18KM444, 18KM245, 18KM583 and 21KM1573 by the absence of α-glucosidase activity and acid production from methyl-β-d-glucopyranoside and maltose. The two novel species can be differentiated from each other by d-ribose metabolism and methyl-β-d-glucopyranoside hydrolysis. 18KM445T, 18KM444, 18KM245, 18KM583 and 21KM1573 formed a distinct cluster of strains, designated Macrococcus equi sp. nov., with strain 18KM445ᵀ (=DSM 118744ᵀ; =CCOS 2124ᵀ; =CCM 9438ᵀ) as the proposed type strain. The second cluster, containing strains EM39Eᵀ, JEK85, 18KM676 and 21M1142, was designated Macrococcus animalis sp. nov., with strain EM39Eᵀ (=DSM 118743ᵀ; =CCOS 2125ᵀ; =CCM 9439ᵀ) as the proposed type strain.

The Chlamydiaceae is a family of strict, intracellular bacteria which include human and animal pathogens such as Chlamydia trachomatis and Chlamydia psittaci. Following the death of multiple Ancistrus dolichopterus fish (bushymouth catfish) in a tropical aquarium, the specimens were examined for a potential infectious agent. To do so, McCoy cells (ATCC CRL-1696) were inoculated with samples isolated from the specimens and became infected by an intracellular bacterium. The entire genome of the infectious agent was sequenced (study accession PRJEB69484) and, based on nine taxonomic markers, was classified as a novel species belonging to the Chlamydia genus (DSMZ no. 117479, CSUR no. QA1836). We propose the name Chlamydia vaughanii sp. nov., in memory of the late Professor Lloyd Vaughan. C. vaughanii has the largest genome (1.3 Mbp) of the Chlamydia genus. This appears to be a consequence of multiple duplications in genes encoding putative adhesins. Like other pathogenic Chlamydia, it can infect mammalian cells, but it cannot infect either insect or amoeba cells. It additionally can grow in Epithelioma papulosum cyprinis (EPC) cells (fathead minnow, ATCC CRL-2872) but only when cultivated at 30 °C. We developed a C. vaughanii-specific quantitative PCR which amplifies the mutS gene and analysed several samples from the aquarium. C. vaughanii was retrieved from all deceased A. dolichopterus fish, but not from any other sample in the aquarium, suggesting that it indeed originated from the fish and was not a contaminant. C. vaughanii is the first Chlamydia isolated from fish.

A Gram-stain-negative, aerobic, rod-shaped bacterium, designated as NT6NT, was isolated from sea foam collected at the Maura Coast of the Noto Peninsula, Ishikawa, Japan. Strain NT6NT was able to grow optimally at pH 7.8, 25–30 °C with 3.5% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NT6NT belonged to the genus Oceaniferula of the family Verrucomicrobiaceae and was most closely related to Oceaniferula flava corrig. 5K15T (98.3%) and Oceaniferula marina N1E253T (95.7%). Furthermore, in silico average nt identity values between strain NT6NT and its closest related species, O. flava 5K15T and O. marina N1E253T, were 76.2% and 70.5%, respectively. The digital DNA–DNA hybridization values for the two comparisons were 20.2% and 19.6%, respectively. The chemotaxonomic characteristics showed that strain NT6NT had MK-9 and MK-8 as its main components of menaquinone and the main cellular fatty acids were iso-C14 : 0, anteiso-C15 : 0, iso-C16 : 0 and iso-C12 : 0. The major polar lipids of strain NT6NT comprised phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The genome of strain NT6NT had a length of 4.65 Mbp with 52.1 mol% G+C content, containing 3,914 protein-coding genes and 68 RNA genes. Based on the results of our phylogenetic, phenotypic, genotypic and chemotaxonomic analyses, it is concluded that strain NT6NT represents a novel species within the genus Oceaniferula, for which the name Oceaniferula spumae sp. nov. is proposed. The type strain is NT6NT (=JCM 36658T=DSM 117338T=MCCC 1K09726T).

A novel moderately halophilic and alkaliphilic Gram-stain-negative, strictly aerobic, bacterial strain (N2T) was isolated from an inland saltern in central Portugal. The taxonomic position of this isolate was determined based on polyphasic taxonomic and phylogenomic analysis. Phylogenetic analysis based on 16S rRNA gene sequences indicated that isolate N2T belongs to the genus Fodinibius, showing the highest similarity to Fodinibius halophilus 2W32T (98.14%). Phylogenomic analysis based on whole genomes, using the up-to-date bacterial core gene sets (92 genes), showed that strain N2T formed a distinct monophyletic lineage within the genus Fodinibius. The cells of N2T were motile rods that grew at temperatures between 30 and 40 °C (optimum at 35 °C), pH levels of 6.0–11.0 (optimum at pH 9.0) and salinities of 13–20 % (w/v) NaCl (optimum at 15% NaCl). Cells tested positive for oxidase and catalase activity. The predominant isoprenoid quinone was menaquinone-7 (MK-7), and the major fatty acids were iso-C15:0, anteiso-C15:0, C16:1  ω6c and/or 10-methyl C16:0. The polar lipids included two aminolipids, two glycolipids and seven phospholipids. The DNA G+C content was 42.0 mol%. Based on phylogenetic, phylogenomic, genomic, phenotypic and chemotaxonomic data, we propose that strain N2T (=KCTC 102228T=MCCC 1K08942T) represents a novel species within the genus Fodinibius, with the name Fodinibius alkaliphilus sp. nov. We also propose the reclassification of Alifodinibius salipaludis as Fodinibius salipaludis sp. nov.

Legionella-like isolates, HB10 and PATHC038T, were isolated from a cold water distribution system on a cruise ship in 2017. The strains have been characterized by employing discriminatory genome typing, matrix-assisted laser desorption/ionization time-of-flight MS technique, fatty acid profiling and biochemical tests, thus identifying a new species in the genus Legionella. Colonies displayed phenotypic characteristics typical of the family Legionellaceae, including a requirement for l-cysteine and testing catalase positive. Fatty acid methyl ester analysis showed that the predominant fatty acids detected in the studied strains are C16:0 iso, C16:1 ω7c, C16:0 and C15:0 anteiso. The obtained MIC values showed antimicrobial susceptibility to the antimicrobial drugs ciprofloxacin and erythromycin (0.8 and 2 µg ml−1, respectively). The bacteria were also Gram-negative, rod-shaped, grew aerobically on buffered charcoal yeast extract agar and weakly grew on glycine-vancomycin-polymyxin-cycloheximide media at 36 °C with the ability to autofluoresce a blue-white colour when placed under a long-wavelength UV light (365 nm). The whole-genome sequencing performed displayed a G+C content of 38.2 mol%. The digital DNA–DNA hybridization analysis demonstrated a separation from the phylogenetically most related Legionella cherrii, with 54.7% DNA–DNA relatedness. The identity percentage measured by average nucleotide identity between the PATHC038T strain and its respective closest species, L. cherrii, was 93.9%, also confirming the distinctiveness of the novel species. The 16S rRNA gene, mip and rpoB sequences showed a similarity of 98.7, 98.4 and 96.2%, respectively, with L. cherrii NCTC 11976T. Additionally, average amino acid identity and percentage of conserved proteins analyses further supported their classification as a novel species. The results obtained in this study confirm the status of an independent species. The name proposed for this species is Legionella sheltonii sp. nov. with PATHC038T (CCUG 76918T, ATCC TSD-370) as the type strain.

A novel bacterium, designated strain 2305UL40-4T, was isolated from Cellana toreuma (a Korean limpet) collected from Ulleung Island, Republic of Korea. The cells were Gram-stain-negative, aerobic, rod-shaped (0.5–0.9 µm×1.5–2.2 µm) and non-motile. Growth was observed at 22–36 °C (optimum 25–30 °C), pH 6–8 (optimum pH 7) and in the presence of 0.5–4.0% (w/v, optimum 2.0%) NaCl. The 16S rRNA gene sequence analysis revealed that strain 2305UL40-4T shared 97.4% similarity with Aestuariibius insulae DBTF-13T. The average nucleotide identity value between the two strains was 76.5%, and the digital DNA–DNA hybridization value was 19.0%. Both values are well below the species delineation thresholds. The DNA G+C content of strain 2305UL40-4T was 63.8 mol%. The major fatty acids were C16 : 0, C18 : 0 and summed feature 8 (C18 : 1  ω7c and/or C18 : 1  ω6c). Major polar lipids included phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine, five unidentified aminolipids and fifteen unidentified lipids. Ubiquinone-10 was the predominant quinone. The new strain differs from A. insulae in its ability to utilize d-raffinose, d-ribose and d-xylose. Based on these polyphasic taxonomic characteristics, strain 2305UL40-4T is proposed as a novel species within the genus Aestuariibius, with the name Aestuariibius violaceus sp. nov. The type strain is 2305UL40-4T (=KCCM 43505T=MCCC 1K09164T).

Two Gram-negative, oxidase-positive, catalase-positive, non-spore-forming, motile, short-rod strains (G13T and G34) were isolated from in situ coal block samples. Phylogenetic analyses based on 16S rRNA genes and 718 core genes indicated that both strains belonged to the genus Brachymonas, with the closest relative being Brachymonas chironomi AIMA4T as their closest relative. Average nucleotide identity and digital DNA–DNA hybridization values were 79.4–89.27% and 23.6–37.0% below the species-level thresholds. Further chemotaxonomic analysis revealed that both strains possessed C16:1 ω7c and/or C16:1 ω6c, C18:1 ω7c and C16:0 as major cellular fatty acids, with Q-8 as the predominant respiratory quinone. The polar lipid profile was dominated by diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Phenotypic and phylogenetic evidence support the proposal that strain G13T represents a novel species of the genus Brachymonas, with the name Brachymonas wangyanguii sp. nov. The type strain is G13T (=GDMCC 1.4691T=JCM 37746T).