- Volume 74, Issue 4, 2024

Facultatively anaerobic bacterial strains were isolated from samples of a methanogenic reactor and, based on 16S rRNA gene sequences, found to be affiliated with the family Propionibacteriaceae in the phylum Actinomycetota. Four strains with almost-identical 16S rRNA gene sequences were comprehensively characterized. The most closely related species to the strains was Brooklawnia cerclae BL-34T (96.4 % sequence similarity). Although most of the phenotypic characteristics of the four strains were identical, distinct differences in some cellular and physiological properties were also detected. Cells of the strains were Gram-stain-positive, non-spore-forming, pleomorphic rods. The strains utilized carbohydrates and organic acids. The strains produced acetate, propionate and lactate from glucose, but the molar ratios of the products were variable depending on the strains. The strains grew at 10–40 °C (optimum at 35 °C) and pH 5.3–8.8 (optimum at pH 6.8–7.5.) The major cellular fatty acids of the strains were anteiso-C15 : 0, C15 : 0 and C15 : 0 dimethylacetal (as a summed feature). The major respiratory quinone was menaquinone MK-9(H4) and the diagnostic diamino acid in the peptidoglycan was meso-diaminopimelic acid. The genome size of the type strain (SH051T) was 3.21 Mb and the genome DNA G+C content was 65.7 mol%. Genes responsible for propionate production through the Wood–Werkman pathway were detected in the genome of strain SH051T. Based on the results of phylogenetic, genomic and phenotypic analyses of the novel strains, the name Brooklawnia propionicigenes sp. nov. is proposed to accommodate the four strains. The type strain of the novel species is SH051T (=NBRC 116195T=DSM 116141T).

An aerobic, non-motile, Gram-stain-positive bacterium, designated strain NEAU-Y5T, was isolated from a soil sample collected from Northeast Agricultural University, Heilongjiang province. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NEAU-Y5T belonged to the genus and showed high 16S rRNA sequence similarity to Isoptericola variabilis (98.9 %), Isoptericola nanjingensis (98.9 %), Isoptericola cucumis (98.5 %), Isoptericola hypogeus (98.5 %), Isoptericola dokdonensis (98.5 %), Isoptericola jiangsuensis (98.3 %), and Isoptericola halalbus (98.1 %), followed by other members of the genus Isoptericola (<98 %), and phylogenetically clustered with I. dokdonensis and I. jiangsuensis. Strain NEAU-Y5T was found to grow at 4–40 °C (optimum, 28 °C), pH 6.0–12.0 (optimum, pH 7.0), and tolerated 0–6 % NaCl (w/v). The cell-wall peptidoglycan type was l-Lys–d-Asp. The whole-cell hydrolysates contained glucose, galactose, and ribose. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside, and glucosamine unknown phospholipid. Major fatty acids were anteiso-C15 : 0 and anteiso-C17 : 0. The predominant menaquinone was MK-9(H4). The DNA G+C content was 73.4 mol%. The digital DNA–DNA hybridization and average nucleotide identity values between strain NEAU-Y5T and the type strains of the genus Isoptericola ranged from 18.6 to 23.5 % and from 77.3 to 81.6 %, respectively. Based on morphological, physiological, chemotaxonomic, and phylogenetic data, as well as digital DNA–DNA hybridization and average nucleotide identity values, the novel strain NEAU-Y5T could be differentiated from its closest relatives. Therefore, the strain represents a novel species of the genus Isoptericola, for which the name Isoptericola luteus sp. nov. is proposed. The type strain is NEAU-Y5T (=CCTCC AA 2019087T=DSM 110637T).

A Gram-stain-negative, rod-shaped, indole-producing, and cellulose-degrading bacterial strain, designated NEAU-G-C5T, was isolated from soil collected from a forest in Dali city, Yunnan province, south China. 16S rRNA gene sequence analysis showed that strain NEAU-G-C5T was assigned to the genus Massilia and showed high sequence similarities to Massilia phosphatilytica 12-OD1T (98.32 %) and Massilia putida 6 NM-7T (98.41 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NEAU-G-C5T formed a lineage related to M. phosphatilytica 12-OD1T and M. putida 6 NM-7T. The major fatty acids of the strain were C16 : 0, C16 : 1 ω7c, and C17 : 0 cyclo. The respiratory quinone was Q-8. The polar lipid profile of the strain showed the presence of diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. In addition, the average nucleotide identity values between strain NEAU-G-C5T and its reference strains M. phosphatilytica 12-OD1T, M. putida 6 NM-7T, M. norwichensis NS9T, and M. kyonggiensis TSA1T were 89.7, 88.2, 81.3, and 88.0 %, respectively, and the levels of digital DNA–DNA hybridization between them were found to be 58.5 % (54.9–62.0 %), 53.2 % (49.8–56.7 %), 31.9 % (28.6–35.5 %), and 57.7 % (54.1–61.2 %), respectively, which were lower than the accepted threshold values of 95–96 % and 70 %, respectively. The DNA G+C content of strain NEAU-G-C5T was 66.5 mol%. The strain could produce indoleacetic acid and cellulase. On the basis of the phenotypic, genotypic, and chemotaxonomic characteristics, we conclude that strain NEAU-G-C5T represents a novel species of the genus Massilia, for which the name Massilia luteola sp. nov. is proposed. The type strain is NEAU-G-C5T (=MCCC 1K08668T=KCTC 8080T).

A novel actinobacterium, strain HUAS 3T, was isolated from the rhizosphere soil of Cathaya argyrophylla collected in Hunan Province, PR China. Strain HUAS 3T contained meso-diaminopimelic acid in the cell-wall peptidoglycan. The dominant menaquinones were MK-9(H4), MK-9(H6), MK-10(H2) and MK-9(H4). The polar lipids consisted of diphosphatidylglycerol, phospholipids, phosphatidylethanolamine, phosphatidylglycerol, phosphotidylinositol and phosphatidylinositol mannosides. The main cellular fatty acids (>5.0 %) were C17 : 1 ω8c, iso-C16 : 0, C18 : 1 ω9c, iso-C15 : 0, C16 : 0 and summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c). The DNA G+C content of the novel strain's genome sequence, consisting of 7 196 442 bp, was 72.8 mol%. The full-length 16S rRNA gene sequence analysis indicated that strain HUAS 3T belonged to the genus Micromonospora and showed highest similarities to Micromonospora fluminis A38T (99.44 %), Micromonospora echinospora DSM 43816T (99.23 %), Micromonospora tulbaghiae DSM 45142T (99.23 %), Micromonospora solifontis PPF5-17T (99.16 %) and Micromonospora endolithica DSM 44398T (98.96 %). Phylogenetic trees based on 16S rRNA gene sequences showed that strain HUAS 3T was closely related to M. fluminis A38T, M. tulbaghiae DSM 45142T and M. solifontis PPF5-17T. The phylogenomic tree revealed that strain HUAS 3T was closely related to Micromonospora pallida DSM 43817T. However, the average nucleotide identity (ANIb/ANIm) and the digital DNA–DNA hybridization values between them were 84.75 /88.16 and 30.80 %, respectively, far less than the 95–96 and 70 % cut-off points recommended for delineating species. Furthermore, strain HUAS 3T was distinct from the type strain of M. pallida in terms of phenotypic and chemotaxonomic characteristics. In summary, strain HUAS 3T represents a novel Micromonospora species, for which the name Micromonospora cathayae sp. nov. is proposed. The type strain is HUAS 3T (=MCCC 1K08599T=JCM 36275T).

The taxonomic position of three actinobacterial strains, BCCO 10_0061T, BCCO 10_0798T, and BCCO 10_0856T, recovered from bare soil in the Sokolov Coal Basin, Czech Republic, was established using a polyphasic approach. The multilocus sequence analysis based on 100 single-copy genes positioned BCCO 10_0061T in the same cluster as Lentzea waywayandensis, strain BCCO 10_0798T in the same cluster as Lentzea flaviverrucosa, Lentzea californiensis, Lentzea violacea, and Lentzea albidocapillata, and strain BCCO 10_0856T clustered together with Lentzea kentuckyensis and Lentzea alba. Morphological and chemotaxonomic characteristics of these strains support their assignment to the genus Lentzea. In all three strains, MK-9(H4) accounted for more than 80 % of the isoprenoid quinone. The diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The whole-cell sugars were rhamnose, ribose, mannose, glucose, and galactose. The major fatty acids (>10 %) were iso-C15 : 0, anteiso-C15 : 0, iso-C16 : 0, and C16 : 0. The polar lipids were diphosphatidylglycerol, methyl-phosphatidylethanolamine, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylglycerol, and phosphatidylinositol. The genomic DNA G+C content of strains (mol%) was 68.8 for BCCO 10_0061T, 69.2 for BCCO 10_0798T, and 68.5 for BCCO 10_0856T. The combination of digital DNA–DNA hybridization results, average nucleotide identity values and phenotypic characteristics of BCCO 10_0061T, BCCO 10_0798T, and BCCO 10_0856T distinguishes them from their closely related strains. Bioinformatic analysis of the genome sequences of the strains revealed several biosynthetic gene clusters (BGCs) with identities >50 % to already known clusters, including BGCs for geosmin, coelichelin, ε-poly-l-lysine, and erythromycin-like BGCs. Most of the identified BGCs showed low similarity to known BGCs (<50 %) suggesting their genetic potential for the biosynthesis of novel secondary metabolites. Based on the above results, each strain represents a novel species of the genus Lentzea, for which we propose the name Lentzea sokolovensis sp. nov. for BCCO 10_0061T (=DSM 116175T), Lentzea kristufekii sp. nov. for BCCO 10_0798T (=DSM 116176T), and Lentzea miocenica sp. nov. for BCCO 10_0856T (=DSM 116177T).

A novel strain, MA3_2.13T, was isolated from deep-sea sediment of Madeira Archipelago, Portugal, and characterized using a polyphasic approach. This strain produced dark brown soluble pigments, bronwish black substrate mycelia and an aerial mycelium with yellowish white spores, when grown on GYM 50SW agar. The main respiratory quinones were MK-10(H4), MK-10(H6) and MK-10(H8). Diphosphatidylglycerol, phosphatidylethanolamine, three unidentified phospholipids and two glycophospholipids were identified as the main phospholipids. The major cellular fatty acids were iso-C16 : 1, iso-C16 : 0, anteiso-C17 : 1 and anteiso-C17 : 0. Phylogenetic analyses based on 16S rRNA gene showed that strain MA3_2.13T is a member of the genus Streptomyces and was most closely related to Streptomyces triticirhizae NEAU-YY642T (NR_180032.1; 16S rRNA gene similarity 97.9 %), Streptomyces sedi YIM 65188T (NR_044582.1; 16S rRNA gene similarity 97.4 %), Streptomyces mimosae 3MP-10T (NR_170412.1; 16S rRNA gene similarity 97.3 %) and Streptomyces zhaozhouensis NEAU-LZS-5T (NR_133874.1; 16S rRNA gene similarity 97.0 %). Genome pairwise comparisons with closest related type strains retrieved values below the threshold for species delineation suggesting that strain MA3_2.13T represents a new branch within the genus Streptomyces. Based on these results, strain MA3_2.13T (=DSM 115980T=LMG 33094T) is proposed as the type strain of a novel species of the genus Streptomyces, for which the name Streptomyces profundus sp. nov. is proposed.

A novel bifidobacterium (designated F753-1T) was isolated from the gut of honeybee (Apis mellifera). Strain F753-1T was characterized using a polyphasic taxonomic approach. Strain F753-1T 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 F753-1T was most closely related to the type strains of B. mellis and B. choladohabitans. Strain F753-1T had the highest average nucleotide identity (94.1–94.5 %) and digital DNA–DNA hybridization (56.3 %) values with B. mellis Bin7NT. 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 F753-1T from B. mellis CCUG 66113T and B. choladohabitans JCM 34586T. Based upon the data obtained in the present study, a novel species, Bifidobacterium apis sp. nov., is proposed, and the type strain is F753-1T (=CCTCC AB 2023227T=JCM 36562T=LMG 33388T).

A novel mesophilic, hydrogenotrophic methanogen, strain CWC-04T, was obtained from a sediment sample extracted from a gravity core retrieved at station 22 within the KP-9 area off the southwestern coast of Taiwan during the ORIII-1368 cruise in 2009. Cells of strain CWC-04T were rod-shaped, 1.4–2.9 µm long by 0.5–0.6 µm wide, and occurred singly. Strain CWC-04Tutilized formate, H2/CO2, 2-propanol/CO2 or 2-butanol/CO2 as catabolic substrates. The optimal growth conditions were 42 °C, 0.17 M NaCl and pH 5.35. The genomic DNA G+C content calculated from the genome sequence of strain CWC-04T was 46.19 mol%. Phylogenetic analysis of 16S rRNA gene revealed that strain CWC-04T is affiliated with the genus Methanocella. The 16S rRNA gene sequences similarities within strains Methanocella arvoryzae MRE50T, Methanocella paludicola SANAET and Methanocella conradii HZ254T were 93.7, 93.0 and 91.3 %, respectively. In addition, the optical density of CWC-04T culture dropped abruptly upon entering the late-log growth phase, with virus-like particles (150 nm in diameter) being observed on and around the cells. This observation suggests that strain CWC-04T harbours a lytic virus. Based on these phenotypic, phylogenetic and genomic results, we propose that strain CWC-04T represents a novel species of a novel genus in the family Methanocellaceae, for which the name Methanooceanicella nereidis gen. nov., sp. nov. is proposed. The type strain is CWC-04T (=BCRC AR10050T=NBRC 113165T).

Strain LB-N7T, a novel Gram-negative, orange, translucent, gliding, rod-shaped bacterium, was isolated from water samples collected from an open system of Atlantic salmon (Salmo salar) smolts in a fish farm in Chile during a flavobacterial infection outbreak in 2015. Phylogenetic analysis based on 16S rRNA sequences (1337 bp) revealed that strain LB-N7T belongs to the genus Flavobacterium and is closely related to the type strains Flavobacterium ardleyense A2-1T (98.8 %) and Flavobacterium cucumis R2A45-3T (96.75 %). The genome size of strain LB-N7T was 2.93 Mb with a DNA G+C content 32.6 mol%. Genome comparisons grouped strain LB-N7T with Flavobacterium cheniae NJ-26T, Flavobacterium odoriferum HXWNR29T, Flavobacterium lacisediminis TH16-21T and Flavobacterium celericrescens TWA-26T. The calculated digital DNA–DNA hybridization values between strain LB-N7T and the closest related Flavobacterium strains were 23.3 % and the average nucleotide identity values ranged from 71.52 to 79.39 %. Menaquinone MK-6 was the predominant respiratory quinone, followed by MK-7. The major fatty acids were iso-C15 : 0 and anteiso-C15 : 0. The primary polar lipids detected included nine unidentified lipids, two amounts of aminopospholipid and phospholipids, and a smaller amount of aminolipid. Phenotypic, genomic, and chemotaxonomic data suggest that strain LB-N7T (=CECT 30406T=RGM 3221T) represents as a novel bacterial species, for which the name Flavobacterium psychraquaticum sp. nov. is proposed.

Two Gram-negative, non-spore-forming, non-motile, non-flagellated bacteria, designated strains D6T and DH64T, were isolated from surface water of the Pacific Ocean. For strain D6T, growth occurred at 10–40 °C, pH 5.5–9.0 and in the presence of 0–8.0 % NaCl (w/v). For strain DH64T, growth occurred at 10–40 °C, pH 5.5–8.5 and in the presence of 0.5–8.0 % NaCl (w/v). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strains D6T and DH64T both belonged to the genera Flagellimonas, with the highest sequence identities to Flagellimonas taeanensis JCM 17757T (98.2 %) and Flagellimonas marinaquae JCM 11811T (98.6 %), respectively. The 16S rRNA gene sequence identity between strains D6T and DH64T was 95.9 %. The average amino acid identity and digital DNA–DNA hybridization values between the two strains and the nearest phylogenetic neighbours were 66.7–93.3 % and 16.1–38.5 %, respectively. The major respiratory quinone of both strains was menaquinone-6. The major polar lipid was phosphatidylethanolamine. The major fatty acids were identified similarly as iso-C15 : 1 G, iso-C15 : 0 and iso-C17 : 0 3-OH. The genomic G+C contents of strains D6T and DH64T were determined to be 45.5 and 42.6 mol%, respectively. The combined genotypic and phenotypic data show that the strains represent two novel species within genera Flagellimonas, for which the names Flagellimonas baculiformis sp. nov. and Flagellimonas crocea sp. nov. are proposed, with type strains D6T (=MCCC M28982T=KCTC 92604T) and DH64T (=MCCC M28986T=KCTC 92975T).

Salipiger manganoxidans VSW210T was compared with Salipiger marinus CK-I3-6T to examine the taxonomic relationship between the two type strains. In phylogenetic trees drawn using whole genome sequences and 16S rRNA gene sequences, S. manganoxidans VSW210T and S. marinus CK-I3-6T clade together and showed a 99.6 % 16S rRNA sequence similarity. The average amino acid identity (AAI), average nucleotide identity (ANIb and ANIm) and digital DNA–DNA hybridization (dDDH) values between S. manganoxidans VSW210T and S. marinus CK-I3-6T were below 97.5, 97.4, 98.4 and 85.1±2.5 %, respectively, all of which were greater than the species delineation threshold AAI value (95.5 %), ANI value (95–96 %) and dDDH value (70 %). Most phenotypic features between both species were almost identical, although there were some differences. The present results show that Salipiger manganoxidans is a later heterotypic synonym of Salipiger marinus.

A polyphasic taxonomic study was carried out on strain ES2T, isolated from sediment of a wetland created to remediate acid drainage from a coal mine. The rod-shaped bacterium formed yellow/orange pigmented colonies and produced the pigment flexirubin. The 16S rRNA gene sequence results assigned the strain to Chryseobacterium, with 98.9 and 98.3 % similarity to Chryseobacterium vietnamense and Chryseobacterium cucumeris, respectively. Computation of the average nucleotide identity and digital DNA–DNA hybridization values with the closest phylogenetic neighbours of ES2T revealed genetic differences at the species level, which were further substantiated by differences in several physiological characteristics. The dominant fatty acids of strain ES2T were iso-C15 : 0, iso-C17 : 1 ω9c, iso C17 : 0 3-OH, and iso-C15 : 0 2-OH. The DNA G+C content was 35.5 mol%. The major polar lipid was phosphatidylethanolamine while menaquinone-6 was the only menaquinone found. This bacterium has been previously shown to possess metallophore activity towards rare earth elements, and based on genome sequencing, possesses all required genes for siderophore production/activity, possibly identifying the source of this unique ability. On the basis of the results obtained here, this bacterium is assigned to the genus Chryseobacterium as representing a new species with the name Chryseobacterium metallicongregator sp. nov., type strain ES2T (=NRRL B-65679T=KCTC 102120T).

Strain Ran72T, a novel Gram-stain-negative, obligately aerobic, non-motile, and rod-shaped bacterium, was isolated from the faeces of the rhinoceros species Ceratotherium simum. The novel bacterial strain grew optimally in Reasoner's 2A medium under the following conditions: 0 % (w/v) NaCl, pH 7.5, and 30 °C. Based on phylogenetic analysis using 16S rRNA gene sequencing, strain Ran72T was found to be most closely related to Chryseobacterium faecale F4T (98.4 %), Kaistella soli DKR-2T (98.0 %), and Kaistella haifensis H38T (97.4 %). A comprehensive genome-level comparison between strain Ran72T with C. faecale F4T, K. soli DKR-2T, and K. haifensis H38T revealed average nucleotide identity, digital DNA–DNA hybridization, and average amino acid identity values of ≤74.9, ≤19.3, and ≤78.7 %, respectively. The major fatty acids were anteiso-C15 : 0 (22.3 %), with MK-6 being the predominant respiratory quinone. The major polar lipids of strain Ran72T were phosphatidylethanolamine, four unidentified aminolipids, and two unidentified lipids. Based on our chemotaxonomic, genotypic, and phenotype characterizations, strain Ran72T was identified as representing a novel species in the genus Kaistella, for which the name Kaistella rhinocerotis sp. nov. is proposed, with the type strain Ran72T (=KACC 23136T=JCM 36038T). Based on the outcomes of our phylogenomic study, Chryseobacterium faecale should be reclassified under the genus Kaistella as Kaistella faecalis comb. nov.

Three Gram-stain-negative, aerobic, rod-shaped, non-motile strains (DC2WT, DC25WT, and LKC2W) were isolated from streams in China. Comparisons based on the 16S rRNA gene sequences showed that these three strains share 16S rRNA gene sequence similarity values over 97.0 % with the species of genus Arcicella. There was confusion due to the fact that all species of genera Flectobacillus, Aquirufa, and Sandaracinomonas show 16S rRNA gene sequence similarity of over 90.0 % to the above three strains, but the genus Flectobacillus belongs to the family Spirosomataceae and the genera Aquirufa and Sandaracinomonas belong to the family Cytophagaceae. Observing the phylogenetic trees, strains DC2WT, DC25WT, and LKC2W cluster closely with the species of genus Arcicella, but some species within the families Spirosomataceae and Cytophagaceae are not monophyletic. The phylogenomic tree also showed a confused phylogenetic relationships among these non-monophyletic species. Combining the phylogenetic relationships and average nucleotide identity values, the current taxonomic status of all the genera within the families Spirosomataceae and Cytophagaceae were re-examined. The genera ‘Chryseosolibacter’, ‘Dawidia’, and Chryseotalea should belong to the new family Chryseotaleaceae fam. nov., the genera Arcicella, Flectobacillus, Pseudarcicella, Aquirufa, and Sandaracinomonas should belong to the new family Flectobacillaceae fam. nov., the genera Fluviimonas, Taeseokella, Arcticibacterium, Emticicia, Jiulongibacter, Marinilongibacter, Lacihabitans, and Leadbetterella should belong to the new family Leadbetterellaceae fam. nov., the genus Litoribacter should be reassigned to the family Cyclobacteriaceae, and the genera Arundinibacter and Tellurirhabdus should be reassigned to the family Spirosomataceae. Strains DC2WT and DC25WT are reported to represent two novel species of the genus Arcicella, for which the names Arcicella gelida sp. nov. (type strain DC2WT=GDMCC 1.3209T=KCTC 92559T) and Arcicella lustrica sp. nov. (type strain DC25WT=GDMCC 1.3210T=KCTC 92557T) are proposed.

A novel Gram-positive strain, B1T, was isolated from uranium-contaminated soil. The strain was aerobic, rod-shaped, spore-forming, and motile. The strain was able to grow at 20−45 °C, at pH 6.0–9.0, and in the presence of 0–3 % (w/v) NaCl. The complete genome size of the novel strain was 3 853 322 bp. The genomic DNA G+C content was 45.5 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain B1T has the highest similarity to Aneurinibacillus soli CB4T (96. 71 %). However, the novel strain showed an average nucleotide identity value of 89.02 % and a digital DNA–DNA hybridization value of 37.40 % with strain CB4T based on the genome sequences. The major fatty acids were iso-C15 : 0 and C16 : 0. The predominate respiratory quinone was MK7. Diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, unidentified phospholipids, an unidentified aminolipid and an unidentified lipid were identified as the major polar lipids. The phylogenetic, phenotypic, and chemotaxonomic analyses showed that strain B1T represents a novel species of the genus Aneurinibacillus, for which the name Aneurinibacillus uraniidurans sp. nov. is proposed. The type strain is B1T (=GDMCC 1.4080T=JCM 36228T). Experiments have shown that strain B1T demonstrates uranium tolerance.

Two Gram-positive, rod-shaped, endospore-forming strains, YIM B05601 and YIM B05602T, were isolated from soil sampled at Hamazui hot spring, Tengchong City, Yunnan Province, PR China. Phylogenetic analysis based on 16S rRNA gene sequences suggested that the two strains fell within the genus Paenibacillus, appearing most closely related to Paenibacillus alkalitolerans YIM B00362T (96.9 % sequence similarity). Genome-based phylogenetic analysis confirmed that strains YIM B05601 and YIM B05602T formed a distinct phylogenetic cluster within the genus Paenibacillus. The average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values of strains YIM B05601 and YIM B05602T with the related species P. alkalitolerans YIM B00362T were within the ranges of 74.43–74.57 % and 12.1–18.5 %, respectively, which clearly indicated that strains YIM B05601, YIM B05602T represented a novel species. Strains YIM B05601 and YIM B05602T exhibited 99.6 % 16S rRNA gene sequence similarity. The ANI and dDDH values between the two strains were 99.8 and 100 %, respectively, suggesting that they belong to the same species. Optimum growth for both strains occurred at pH 7.0 and 45 °C. The diagnostic diamino acid in the cell-wall peptidoglycan of strains YIM B05601 and YIM B05602T was meso-diaminopimelic acid. MK-7 was the predominant menaquinone. The polar lipids of strain YIM B05602T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, four unidentified glycolipids, an unidentified polarlipid and phosphatidylinositol mannoside. The major fatty acids of the two stains were iso-C15 : 0 and anteiso-C15 : 0. Based on phylogenomic and phylogenetic analyses coupled with phenotypic and chemotaxonomic characterizations, strains YIM B05601 and YIM B05602T could be classified as a novel species of the genus Paenibacillus, for which the name Paenibacillus thermotolerans sp. nov. is proposed. The type strain is YIM B05602T (=CGMCC 1.60051T=KCTC 43460T=NBRC 115924T).

Three Gram-positive, obligately anaerobic bacterial strains, namely CSJ-1T, CSJ-3T, and CSJ-4T, were isolated from faeces of healthy persons. They were characterized through a combination of whole-genome sequencing, phenotypic traits, and metabolomic analysis. The genome sizes of CSJ-1T, CSJ-4T, and CSJ-3T were 3.3, 3.8, and 6.1 Mbp, with DNA G+C contents of 47.2, 48.3, and 48.8 mol%, respectively. Strain CSJ-3T was identified as representing a novel species, Diplocloster hominis (type strain CSJ-3T=CGMCC 1.18033T=JCM 36512T) of the genus Diplocloster. The 16S rRNA gene sequence similarity and whole genome average nucleotide identity (gANI) of CSJ-4T to its closest related species, Diplocloster modestus ASD 4241T, were 98.3 and 91.4 %, respectively. Comparative analysis of 16S rRNA gene sequences showed 91.6 % similarity between CSJ-1T and its closest phylogenetic neighbour, Catenibacillus scindens DSM 106146T, and 93.3 % similarity between CSJ-4T and its closest relative strain, Clostridium fessum SNUG30386T. Based on the polyphasic taxonomic results, we proposed two novel genera and three novel species. Strain CSJ-1T was identified as representing a novel species of novel genus, Anaerolentibacter hominis gen. nov. sp. nov. (type strain CSJ-1T=CGMCC 1.18046T=JCM 36511T) of the family Lachnospiraceae, and strain CSJ-4T was identified as representing a novel species of novel genus Pilosibacter fragilis gen. nov. sp. nov. (type strain CSJ-4T=CGMCC 1.18026T= JCM 36513T) of the family Clostridiaceae.