Search

Biodegradation stands as an eco-friendly and effective approach for organic contaminant remediation. However, research on microorganisms degrading sodium benzoate contaminants in extreme environments remains limited. In this study, we report to display the isolation of a novel hot spring enriched cultures with sodium benzoate (400 mg/L) as the sole carbon source. The results revealed that the phylum Pseudomonadota was the potential sodium benzoate degrader and a novel genus within the family Geminicoccaceae of this phylum. The isolated strain was named Benzoatithermus flavus SYSU G07066 T and was isolated from HNT-2 hot spring samples. Genomic analysis revealed that SYSU G07066 T carried benABC genes and physiological experiments indicated the ability to utilize sodium benzoate as a sole carbon source for growth, which was further confirmed by transcriptomic data with expression of benABC. Phylogenetic analysis suggested that Horizontal Gene Transfer (HGT) plays a significant role in acquiring sodium benzoate degradation capability among prokaryotes, and SYSU G07066 T might have acquired benABC genes through HGT from the family Acetobacteraceae. The discovery of the first microorganism with sodium benzoate degradation function from a hot spring enhances our understanding of the diverse functions within the family Geminicoccaceae. This study unearths the first novel genus capable of efficiently degrading sodium benzoate and its evolution history at high temperatures, holding promising industrial applications, and provides a new perspective for further exploring the application potential of hot spring "microbial dark matter"., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Strain SYSU D00308 T , a short-rod-shaped bacterium, was isolated from a sandy soil collected from the Gurbantunggut Desert, Xinjiang, PR China. Strain SYSU D00308 T was Gram-stain-negative, aerobic, pink-pigmented, non-motile, catalase- and oxidase-positive. The strain grew at 4-37 ℃, pH 5.0-8.0 and 0-1.5% (w/v) NaCl. 16S rRNA gene sequencing analyses demonstrated that strain SYSU D00308 T belonged to the genus Rufibacter and exhibited the highest sequence similarity (97.4%) to Rufibacter glacialis MDT1-10-3 T . Summed features 3, 4, and iso-C 15:0 were the major fatty acids, and menaquinone 7 (MK-7) was the sole respiratory menaquinone. The polar lipid profiles comprised phosphatidylethanolamine, an unidentified glycolipid, an unidentified phospholipid, two unidentified aminophospholipids, and two unidentified lipids. The genome size and DNA G + C content of strain SYSU D00308 T were 5,176,683 bp and 54.8%, respectively. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between SYSU D00308 T and members of the genus Rufibacter were 77.7-81.8% and 20.4-23.4% respectively, which were less than the corresponding thresholds (ANI: 95-96%; dDDH: 70%) for prokaryotic species definition. According to the genotypic, phenotypic and phylogenetic characteristics, strain SYSU D00308 T represents a novel species of the genus Rufibacter. We propose the name, Rufibacter psychrotolerans sp. nov., with SYSU D00308 T (= CGMCC 1.18621 T = KCTC 82275 T = MCCC 1K04970 T ) as the type strain., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The strain designated NCCP-602 T was isolated from tannery effluent, and displayed aerobic, gram-positive, rod-shaped cells that were characterized by oxidase negative, catalase positive, and non-motile features. The most favourable growth conditions were observed at a temperature of 30°C, pH 7.0, and NaCl concentration of 1% (w/v). It tolerated heavy metals at high concentrations of chromium (3600 ppm), copper (3300 ppm), cadmium (3000 ppm), arsenic (1200 ppm) and lead (1500 ppm). The results of phylogenetic analysis, derived from sequences of the 16S rRNA gene, indicated the position of strain NCCP-602 T within genus Brevibacterium and showed that it was closely related to Brevibacterium ammoniilyticum JCM 17537 T . Strain NCCP-602  T formed a robust branch that was clearly separate from closely related taxa. A comparison of 16S rRNA gene sequence similarity and dDDH values between the closely related type strains and strain NCCP-602 T provided additional evidence supporting the classification of strain NCCP-602 T as a distinct novel genospecies. The polar lipid profile included diphosphatidylglycerol, glycolipid, phospholipids and amino lipids. MK-7 and MK-8 were found as the respiratory quinones, while anteiso-C 15:0 , iso-C 15:0 , iso-C 16:0 , iso-C 17:0 , and anteiso-C 17:0 were identified as the predominant cellular fatty acids (> 10%). Considering the convergence of phylogenetic, phenotypic, chemotaxonomic, and genotypic traits, it is suggested that strain NCCP-602  T be classified as a distinct species Brevibacterium metallidurans sp. nov. within genus Brevibacterium with type strain NCCP-602 T (JCM 18882 T  = CGMCC1.62055 T )., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

We aimed to elucidate the relationship between Kineococcus terrestris and Kineococcus aureolus through whole-genome-based analysis. The genome-derived 16S rRNA gene sequences of K. terrestris KCTC 39738 T and K. aureolus KCTC 39739 T shared a 100% similarity. Phylogenetic trees based on 16S rRNA gene and whole-genome sequences revealed that K. terrestris KCTC 39738 T and K. aureolus KCTC 39739 T formed a robust clade, indicating a close relationship between them. Genomic comparison showed that the two strains shared 99.1% average nucleotide identity, 92.0% digital DNA-DNA hybridization and 98.9% average amino acid identity values, all of which exceeded the recommended threshold values for species classification. Most phenotypic characteristics between the two species were almost identical. Based on the above evidence, we propose the reclassification of Kineococcus aureolus Xu et al . 2017 as a later heterotypic synonym of Kineococcus terrestris Xu et al . 2017. Since these two species were proposed in the same article, the principle of priority does not apply. Our proposal is supported by the fact that the nomenclatural authorities first described Kineococcus terrestris .

Objective: The family Paenibacillaceae is linked to the order Caryophanales. Paenibacillaceae members residing in compost or soil play crucial roles in nutrient recycling and breaking down complex organic materials. However, our understanding of Paenibacillaceae remains limited., Methods: Strain SYSU GA230002 T was conclusively identified using a polyphasic taxonomic approach frequently utilized in bacterial systematics. Standard microbiological techniques were employed to characterize the morphology and biochemistry of strain SYSU GA230002 T ., Results: An anaerobic and gram--negative bacterium, designated SYSU GA230002 T , was isolated from geothermally heated soil of Tengchong, Yunnan Province, south-west China. Phylogenetic analyses based on 16S rRNA gene sequences and genomes showed that strain SYSU GA230002 T belongs to the family Paenibacillaceae. 16S rRNA gene sequence similarity (<94.0 %), ANI (<71.95 %) and AAI values (<58.67 %) between strain SYSU GA230002 T with other members of the family were lower than the threshold values recommended for distinguishing novel species. Growth was observed at 30-45 °C (optimum, 37 °C), pH 7.0-8.0 (optimum, pH 7.5) and in 0-3.0 % (w/v) NaCl concentrations (optimum, 0 %). The major fatty acids detected were anteiso-C 15:0 , iso-C 16:0 and iso-C 17:0 . The polar lipids included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, one unidentified phospholipid, one unidentified aminolipid and two unidentified glycolipids. The respiratory quinone was MK-7. The DNA G + C content of strain SYSU GA230002 T was 49.87 %., Conclusion: Based on the results of morphological, physiological properties, and chemotaxonomic characteristics, this strain is proposed to represent a new species of a new genus Ferviditalea candida gen. nov., sp. nov. The type strain of the type species is SYSU GA230002 T (=KCTC 25726 T  = GDMCC 1.4160 T )., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

A novel rod-shaped bacterium, designated as strain SYSU D60015 T that formed yellowish colonies was isolated from a sandy soil collected from the Kumtag Desert in Xinjiang, China. Cells were Gram-stain-negative, oxidase-positive, catalase-negative and motile with a single polar flagellum. Growth optimum occurred between 28 and 37 °C, pH 7.0 and with 0-0.5% (W/V) NaCl. The predominant cellular fatty acids (> 5%) were summed feature 8 (C 18:1 ω7c and/or C 18:1 ω6c), C 19:0 cyclo ω8c, C 18:1 ω7c 11-methyl and C 16:0 . The polar lipid profile contained one phosphatidylethanolamine, one diphosphatidylglycerol, one phosphatidylglycerol, one unidentified phospholipid, three unidentified aminolipids, two unidentified aminophospholipids and seven unidentified lipids. The only respiratory quinone was ubiquinone-10. Based on 16S rRNA gene sequence phylogenetic analysis, strain SYSU D60015 T was found to form a distinct linage within the family Sneathiellaceae, and had 16S rRNA gene sequence similarities of 90.8% to Taonella mepensis H1 T , and 90.2% to Ferrovibrio denitrificans S3 T . The genome of SYSU D60015 T was 5.66 Mb in size with 68.2% of DNA G + C content. The low digital DNA-DNA hybridization (dDDH, 18.0%), average nucleotide identity (ANI, 77.5%) and amino acid identity (AAI, 56.0%) values between SYSU D60015 T and Ferrovibrio terrae K5 T indicated that SYSU D60015 T might represent a distinct genus. Based on the phylogenetic, phenotypic, chemotaxonomic and genomic data, we propose Desertibaculum subflavum gen. nov., sp. nov. as a novel species of a new genus within the family Sneathiellaceae. The type strain is SYSU D60015 T (= NBRC 112952 T  = CGMCC 1.16256 T )., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Genus Thermus is the main focus of researcher among the thermophiles. Members of this genus are the inhabitants of both natural and artificial thermal environments. We performed phylogenomic analyses and comparative genomic studies to unravel the genomic diversity among the strains belonging to the genus Thermus in geographically different thermal springs. Sixteen Thermus strains were isolated and sequenced from hot springs, Qucai hot springs in Tibet and Tengchong hot springs in Yunnan, China. 16S rRNA gene based phylogeny and phylogenomic analyses based on concatenated set of 971 Orthologous Protein Families (supermatrix and gene content methods) revealed a mixed distribution of the Thermus strains. Whole genome based phylogenetic analysis showed, all 16 Thermus strains belong to five species; Thermus oshimai (YIM QC-2-109, YIM 1640, YIM 1627, 77359, 77923, 77838), Thermus antranikianii (YIM 73052, 77412, 77311, 71206), Thermus brokianus (YIM 73518, 71318, 72351), Thermus hydrothermalis (YIM 730264 and 77927) and one potential novel species 77420 forming clade with Thermus thalpophilus SYSU G00506 T . Although the genomes of different strains of Thermus of same species were highly similar in their metabolic pathways, but subtle differences were found. CRISPR loci were detected through genome-wide screening, which showed that Thermus isolates from two different thermal locations had well developed defense system against viruses and adopt similar strategy for survival. Additionally, comparative genome analysis screened competence loci across all the Thermus genomes which could be helpful to acquire DNA from environment. In the present study it was found that Thermus isolates use two mechanism of incomplete denitrification pathway, some Thermus strains produces nitric oxide while others nitrious oxide (dinitrogen oxide), which show the heterotrophic lifestyle of Thermus genus. All isolated organisms encoded complete pathways for glycolysis, tricarboxylic acid and pentose phosphate. Calvin Benson Bassham cycle genes were identified in genomes of T. oshimai and T. antranikianii strains, while genomes of all T. brokianus strains and organism 77420 were lacking. Arsenic, cadmium and cobalt-zinc-cadmium resistant genes were detected in genomes of all sequenced Thermus strains. Strains 77,420, 77,311, 73,518, 77,412 and 72,351 genomes were found harboring genes for siderophores production. Sox gene clusters were identified in all sequenced genomes, except strain YIM 730264, suggesting a mode of chemolithotrophy. Through the comparative genomic analysis, we also identified 77420 as the genome type species and its validity as novel organism was confirmed by whole genome sequences comparison. Although isolate 77420 had 99.0% 16S rRNA gene sequence similarity with T. thalpophilus SYSU G00506 T but based on ANI 95.86% (Jspecies) and digital DDH 68.80% (GGDC) values differentiate it as a potential novel species. Similarly, in the phylogenomic tree, the novel isolate 77,420 forming a separate branch with their closest reference type strain T. thalpophilus SYSU G00506 T ., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Two novel Gram-stain-negative, aerobic, and non-motile strains, designated FZY0004 T and YYF002 T , were isolated from an agar-degrading co-culture, which was obtained from seawater of the intertidal zone of Yancheng City, the Yellow Sea of China. Strain FZY0004 T optimally grew at 28 °C, pH 7.0, and 2-6% NaCl, while strain YYF002 T optimally grew at 28 °C, pH 7.5, and 2-4% NaCl. Strain FZY0004 T possessed Q-9 as the major respiratory quinone, and its major fatty acids (> 10%) were summed feature 8 (C 18:1 ω7c), C 16:0 , and summed feature 3 (C 16:1 ω7c/C 16:1 ω6c). The polar lipids identified in strain FZY0004 T were phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and several unidentified phospholipids (PL) and lipids (L). On the other hand, strain YYF002 T had MK-6 as the predominant respiratory quinone and its major fatty acids consisted of iso-C 15:0 , iso-C 15:1 G, and iso-C 15:0 3-OH. The polar lipids identified in strain YYF002 T were aminolipid (AL), PE, and several unidentified lipids. Strain FZY0004 T shared 99.5% 16S rRNA gene sequence similarity and 90.1% average nucleotide identity (ANI) with T. povalilytica Zumi 95 T , and strain YYF002 T shared 99.2% 16S rRNA gene sequence similarity and 88.2% ANI with W. poriferorum JCM 12885 T . The genomic DNA G + C contents of strains FZY0004 T and YYF002 T were 54.5% and 33.5%, respectively. The phylogenetic, phenotypic, and physiological characteristics permitted the distinction of the two strains from their neighbors, and we thus propose the names Thalassospira aquimaris sp. nov. (type strain FZY0004 T  = JCM 35895 T  = MCCC 1K08380 T ) and Winogradskyella marincola sp. nov. (type strain YYF002 T  = JCM 35950 T  = MCCC 1K08382 T )., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

An aerobic, Gram-stain-negative bacterium, designated as SYSU D00382 T , was sourced from soil of Gurbantunggut Desert, PR China. The strain was short-rod-shaped, oxidase-positive and catalase-negative, with yellow-colored, convex, round, and smooth colonies on TSA plate. Growth and proliferation occurred at 4-37 °C (optimal: 28-30 °C), pH 5.0-8.0 (optimal: pH 6.0-7.0) and NaCl concentration of 0-2.5% (optimal: 0-0.5%). The 16S rRNA gene based phylogenetic assessment showed that SYSU D00382 T belonged to the genus Pedobacter, and was most closely related to Pedobacter ginsengisoli Gsoil 104 T with similarity of 97.7%. The genomic DNA G+C content of SYSU D00382 T was 46.4%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between SYSU D00382 T and P. ginsengisoli Gsoil 104 T were 75.7% and 17.5%, respectively. The main polar lipid was phosphatidylethanolamine. The major fatty acids (> 5%) were iso-C 15:0 , iso-C 17:0 3-OH, summed features 3 and 9. The sole respiratory quinone identified was MK-7. The phylogeny based on 16S rRNA gene and whole-genome sequences revealed that SYSU D00382 T formed a robust lineage with P. ginsengisoli Gsoil 104 T . Based on phenotypic, phylogenetic and genotypic data, a novel specie named Pedobacter deserti sp. nov. is proposed. The type strain is SYSU D00382 T (= CGMCC 1.18627 T  = MCCC 1K04972 T  = KCTC 82279 T )., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: The Atribacterota are widely distributed in the subsurface biosphere. Recently, the first Atribacterota isolate was described and the number of Atribacterota genome sequences retrieved from environmental samples has increased significantly; however, their diversity, physiology, ecology, and evolution remain poorly understood., Results: We report the isolation of the second member of Atribacterota, Thermatribacter velox gen. nov., sp. nov., within a new family Thermatribacteraceae fam. nov., and the short-term laboratory cultivation of a member of the JS1 lineage, Phoenicimicrobium oleiphilum HX-OS.bin.34 TS , both from a terrestrial oil reservoir. Physiological and metatranscriptomics analyses showed that Thermatribacter velox B11 T and Phoenicimicrobium oleiphilum HX-OS.bin.34 TS ferment sugars and n-alkanes, respectively, producing H 2 , CO 2, and acetate as common products. Comparative genomics showed that all members of the Atribacterota lack a complete Wood-Ljungdahl Pathway (WLP), but that the Reductive Glycine Pathway (RGP) is widespread, indicating that the RGP, rather than WLP, is a central hub in Atribacterota metabolism. Ancestral character state reconstructions and phylogenetic analyses showed that key genes encoding the RGP (fdhA, fhs, folD, glyA, gcvT, gcvPAB, pdhD) and other central functions were gained independently in the two classes, Atribacteria (OP9) and Phoenicimicrobiia (JS1), after which they were inherited vertically; these genes included fumarate-adding enzymes (faeA; Phoenicimicrobiia only), the CODH/ACS complex (acsABCDE), and diverse hydrogenases (NiFe group 3b, 4b and FeFe group A3, C). Finally, we present genome-resolved community metabolic models showing the central roles of Atribacteria (OP9) and Phoenicimicrobiia (JS1) in acetate- and hydrocarbon-rich environments., Conclusion: Our findings expand the knowledge of the diversity, physiology, ecology, and evolution of the phylum Atribacterota. This study is a starting point for promoting more incisive studies of their syntrophic biology and may guide the rational design of strategies to cultivate them in the laboratory. Video Abstract., (© 2024. The Author(s).)

Two strains, designated as SYSU M80004 T and SYSU M80005 T , were isolated from water sampled in the Pearl River Estuary, Guangzhou, Guangdong, PR China. The strains were Gram-stain-negative and aerobic. Strain SYSU M80004 T could grow at pH 6.0-8.0 (optimum, pH 7.0), 22-30 °C (optimum, 28 °C) and in the presence of 0-1 % NaCl (w/v; optimum 0 %). Strain SYSU M80005 T could grow at pH 6.0-8.0 (optimum, pH 7.0), 4-37 °C (optimum, 28 °C) and in the presence of 0-1 % NaCl (w/v; optimum 0%). Both strains contained MK-6 as the predominant menaquinone. C 16 : 0 and iso-C 15 : 0 were identified as the major fatty acids (>10 %) of strain SYSU M80004 T while strain SYSU M80005 T contained iso-C 15 : 0 and iso-C 17 : 0 3-OH as major fatty acids. Phosphatidylethanolamine was present as the major polar lipid in both strains. The average nucleotide identity and digital DNA-DNA hybridization values between these two strains and their closest relatives were 73.5-79.3 % and 19.6-23.2 %, respectively. Phylogenetic analysis based on the 16S rRNA gene and genomic sequences indicated they belonged to the genus Flavobacterium . Therefore, on the basis of phenotypic, physiological, chemotaxonomic and genomic evidence, two novel species, Flavobacterium adhaerens sp. nov. (type strain=SYSU M80004 T =CDMCC 1.4522 T =KCTC 102268 T ) and Flavobacterium maritimum sp. nov. (type strain=SYSU M80005 T =CGMCC 1.4523 T = KCTC 102269 T ) are proposed.

Two Gram-stain-negative, aerobic, milk-white coloured, non-motile, short rod-shaped bacteria, designated as strains SYSU D60010 T and SYSU D60012 T , were isolated from sand samples collected from the Taklimakan Desert of Xinjiang Province in China. Both strains were positive for oxidase, catalase and nitrate reduction, but negative for amylase, H 2 S production, hydrolysis of gelatin and cellulase. Strains SYSU D60010 T and SYSU D60012 T grew well at 28 °C, at pH 7 and had the same NaCl tolerance range of 0-1 % (w/v). The major fatty acids (>5 %) of strains SYSU D60010 T and SYSU D60012 T were summed feature 8 (C 18 : 1  ω 7 c and/or C 18 : 1  ω 6 c ), iso-C 19 : 0 cyclo ω 8 c , C 16 : 0 and iso-C 18 : 1 2-OH. Q-10 was the only respiratory ubiquinone. Strains SYSU D60010 T and SYSU D60012 T showed high 16S rRNA gene sequence similarities to Aestuariivirga litoralis SYSU M10001 T (94.2 and 94.1 %), Rhodoligotrophos jinshengii BUT-3 T (92.0 and 91.9 %) and Rhodoligotrophos appendicifer 120-1 T (91.8 and 91.7 %), and the genomes were 7.4 and 5.8 Mbp in size with DNA G+C contents of 62.8 and 63.0 mol%, respectively. Phylogenetic, phenotypic and chemotaxonomic characteristics indicated that these two strains represent a novel genus and two novel species within the family Aestuariivirgaceae . We propose the name Taklimakanibacter deserti gen. nov., sp. nov. for strain SYSU D60010 T , representing the type strain of this species (=KCTC 52783 T =NBRC 113344 T ) and Taklimakanibacter lacteus gen. nov., sp. nov. for strain SYSU D60012 T , representing the type strain of this species (=KCTC 52785 T =NBRC 113128 T ).

Two Gram-stain-positive, aerobic, oxidase- and catalase-negative, non-motile, and short rod-shaped actinomycetes, named SYSU T00b441 T and SYSU T00b490, were isolated from tidal flat sediment located in Guangdong province, PR China. The 16S rRNA gene sequence similarity, average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between SYSU T00b441 T and SYSU T00b490 were 99.3, 99.5 and 97.1 %, respectively. Strains SYSU T00b441 T and SYSU T00b490 exhibited the highest 16S rRNA gene sequence similarities to Actinotalea ferrariae CF 5-4 T (97.1 %/98.2 %), with ANI values of 74.01/73.88 % and dDDH values of 20.5/20.4 %. In the phylogenomic tree, the two isolates were affiliated with the genus Actinotalea . The genomes of strains SYSU T00b441 T and SYSU T00b490 were 3.31 and 3.34 Mb, and both had DNA G+C contents of 72.8 mol%, coding 3077 and 3085 CDSs, three and three rRNA genes, and 53 and 51 tRNAs, respectively. Growth occurred at 15-40 °C (optimum, 28-30 °C), pH 4.0-10.0 (optimum, 7.0) and in the presence of 0-7 % (w/v) NaCl (optimum, 3 %). The major fatty acids (>10  %) of strains SYSU T00b441 T and SYSU T00b490 were anteiso-C 15 : 0 and C 16 : 0 . The major respiratory quinone was identified as MK-10(H 4 ). The polar lipids of strains SYSU T00b441 T and SYSU T00b490 were diphosphatidyl glycerol, phosphatidylglycerol, phosphoglycolipid, phosphatidyl ethanolamine, two phosphatidylinositol mannosides, two glycolipids and two phospholipids. Based on these data, the two strains (SYSU T00b441 T and SYSU T00b490) represent a novel species of the genus Actinotalea , for which the name Actinotalea lenta sp. nov is proposed. The type strain is SYSU T00b441 T (=GDMCC 1.3827 T =KCTC 49943 T ).

The mangrove ecosystem is the world's fourth most productive ecosystem in terms of service value and offering rich biological resources. Microorganisms play vital roles in these ecological processes, thus researching the mangroves-microbiota is crucial for a deeper comprehension of mangroves dynamics. Amplicon sequencing that targeted V4 region of 16S rRNA gene was employed to profile the microbial diversities and community compositions of 19 soil samples, which were collected from the rhizosphere of 3 plant species (i.e., Avicennia marina, Ceriops tagal, and Rhizophora mucronata) in the mangrove forests of Lasbela coast, Pakistan. A total of 67 bacterial phyla were observed from three mangroves species, and these taxa were classified into 188 classes, 453 orders, 759 families, and 1327 genera. We found that Proteobacteria (34.9-38.4%) and Desulfobacteria (7.6-10.0%) were the dominant phyla followed by Chloroflexi (6.6-7.3%), Gemmatimonadota (5.4-6.8%), Bacteroidota (4.3-5.5%), Planctomycetota (4.4-4.9%) and Acidobacteriota (2.7-3.4%), Actinobacteriota (2.5-3.3%), and Crenarchaeota (2.5-3.3%). After considering the distribution of taxonomic groups, we prescribe that the distinctions in bacterial community composition and diversity are ascribed to the changes in physicochemical attributes of the soil samples (i.e., electrical conductivity (EC e ), pH, total organic matter (OM), total organic carbon (OC), available phosphorus (P), and extractable potassium (CaCO 3 ). The findings of this study indicated a high-level species diversity in Pakistani mangroves. The outcomes may also aid in the development of effective conservation policies for mangrove ecosystems, which have been hotspots for anthropogenic impacts in Pakistan. To our knowledge, this is the first microbial research from a Pakistani mangrove forest., (© 2023. Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i.)

An aerobic, Gram-stain-negative, motile rod bacterium, designated as SYSU BS000021 T , was isolated from a black soil sample in Harbin, Heilongjiang province, China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate belongs to the genus Methylobacterium, and showed the highest sequence similarity to Methylobacterium segetis KCTC 62267  T (98.51%) and Methylobacterium oxalidis DSM 24028  T (97.79%). Growth occurred at 20-37℃ (optimum, 28 °C), pH 6.0-8.0 (optimum, pH 7.0) and in the presence of 0% (w/v) NaCl. Polar lipids comprised of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified aminolipid and one unidentified polar lipid. The major cellular fatty acids (> 5%) were C 18:0 and C 18:1 ω7c and/or C 18:1 ω6c. The predominant respiratory quinone was Q-10. The genomic G + C content was 68.36% based on the whole genome analysis. The average nucleotide identity (≤ 83.5%) and digital DNA-DNA hybridization (≤ 27.3%) values between strain SYSU BS000021 T and other members of the genus Methylobacterium were all lower than the threshold values recommended for distinguishing novel prokaryotic species. Based on the results of phenotypic, chemotaxonomic and phylogenetic analyses, strain SYSU BS000021 T represents a novel species of the genus Methylobacterium, for which the name Methylobacterium nigriterrae sp. nov. is proposed. The type strain of the proposed novel species is SYSU BS000021 T (= GDMCC 1.3814  T  = KCTC 8051  T )., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Terrestrial geothermal springs are physicochemically diverse and host abundant populations of Archaea. However, the diversity, functionality, and geological influences of these Archaea are not well understood. Here we explore the genomic diversity of Archaea in 152 metagenomes from 48 geothermal springs in Tengchong, China, collected from 2016 to 2021. Our dataset is comprised of 2949 archaeal metagenome-assembled genomes spanning 12 phyla and 392 newly identified species, which increases the known species diversity of Archaea by ~48.6%. The structures and potential functions of the archaeal communities are strongly influenced by temperature and pH, with high-temperature acidic and alkaline springs favoring archaeal abundance over Bacteria. Genome-resolved metagenomics and metatranscriptomics provide insights into the potential ecological niches of these Archaea and their potential roles in carbon, sulfur, nitrogen, and hydrogen metabolism. Furthermore, our findings illustrate the interplay of competition and cooperation among Archaea in biogeochemical cycles, possibly arising from overlapping functional niches and metabolic handoffs. Taken together, our study expands the genomic diversity of Archaea inhabiting geothermal springs and provides a foundation for more incisive study of biogeochemical processes mediated by Archaea in geothermal ecosystems., (© 2024. The Author(s).)

Two novel actinobacteria, designated as SYSU M7M538 T and SYSU M7M531, were isolated from oral of Eumetopias jubatus in Zhuhai Chimelong Ocean Kingdom, China. The cells of these microorganisms stained Gram-positive and were rod shaped. These strains were facultative anaerobic, and catalase-positive. Optimal growth occurred at 37 °C and pH 7.0 over 7 days of cultivation. Both strains possessed diphosphatidylglycerol, phosphatidylglycerol and phosphocholine as the major polar lipids. The main menaquinone was MK-9(H 4 ). The major fatty acids were C 16:0 , C 17:1 w 8 c , C 17:0 , C 18:1 w 9 c and C 18:0 . Analyses of genome sequences revealed that the genome size of SYSU M7M538 T was 2.1 Mbp with G + C content of 52.5 %, while the genome size of SYSU M7M531 was 2.3 Mbp with G + C content of 52.7 %. The ANI and 16S rRNA gene analysis results showed that the pairwise similarities between the two strains and other recognized Nitriliruptoria species were less than 64.9 % and 89.0 %, respectively. Phylogenetic analysis of the 16S rRNA gene sequences indicated that strains SYSU M7M538 T and SYSU M7M531 formed a well-separated phylogenetic branch distinct from other orders of Nitriliruptoria. Based on the data presented here, these two strains are considered to represent a novel species of a novel genus, for which the name Stomatohabitans albus gen. nov., sp. nov., with the type strain SYSU M7M538 T (=KCTC 59113 T  = GDMCC 1.4286 T ), are proposed. We also propose that these organisms represent a novel family named Stomatohabitantaceae fam. nov. of a novel order Stomatohabitantales ord. nov., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

Two Gram-stain-negative strains, designed SYSU M86414 T and SYSU M84420, were isolated from marine sediment samples of the South China Sea (Sansha City, Hainan Province, PR China). These strains were aerobic and could grow at pH 6.0-8.0 (optimum, pH 7.0), 4-37 °C (optimum, 28 °C), and in the presence of 0-10 % NaCl (w/v; optimum 3 %). The predominant respiratory menaquinone of strains SYSU M86414 T and SYSU M84420 was MK-6. The primary cellular polar lipid was phosphatidylethanolamine. The major cellular fatty acids (>10 %) in both strains were iso-C 15 : 0 , iso-C 15 : 1 G, and iso-C 17 : 0 3-OH. The DNA G+C content of strains SYSU M86414 T and SYSU M84420 were both 42.10 mol%. Phylogenetic analyses based on 16S rRNA gene sequences and core genes indicated that these novel strains belonged to the genus Flagellimonas and strain SYSU M86414 T showed the highest 16S rRNA gene sequence similarity to Flagellimonas marinaquae JCM 11811 T (98.83 %), followed by Flagellimonas aurea BC31-1-A7 T (98.62 %), while strain SYSU M84420 had highest 16S rRNA gene sequence similarity to F. marinaquae JCM 11811 T (98.76 %) and F. aurea BC31-1-A7 T (98.55 %). Based on the results of polyphasic analyses, strains SYSU M86414 T and SYSU M84420 should be considered to represent a novel species of the genus Flagellimonas , for which the name Flagellimonas halotolerans sp. nov. is proposed. The type strain of the proposed novel isolate is SYSU M86414 T (=GDMCC 1.3806 T =KCTC 102040 T ).

Two novel bacterial strains, designated as SYSU D00823 T and SYSU D00873 T , were isolated from sandy soil of the Gurbantunggut Desert in Xinjiang, north-west China. SYSU D00823 T and SYSU D00873 T shared 99.0 % 16S rRNA gene sequence identity, and were both most closely related to Pedobacter xinjiangensis 12157 T with 96.1 % and 96.0 % similarities, respectively. Phylogenetic and phylogenomic analyses revealed that the two isolates and P. xinjiangensis 12157 T formed a separate distinct cluster in a stable subclade with the nearby species Pedobacter mongoliensis 1-32 T , as well as the genera Pararcticibacter and Arcticibacter . Furthermore, P. mongoliensis 1-32 T formed a separate deep-branching lineage and did not form a cluster with members of the genus Pedobacter . The average nucleotide identity and digital DNA-DNA hybridization values between SYSU D00823 T and SYSU D00873 T and related species were well below the thresholds for species delineation (<81.0 % and <24.0 %, respectively). The genomes of SYSU D00823 T and SYSU D00873 T were 6.19 and 6.43 Mbp in size with 40.4 % and 40.5 % DNA G+C contents, respectively. The predominant fatty acids (>10 %) of SYSU D00823 T and SYSU D00873 T were iso-C 15 : 0 , iso-C 17 : 0 3-OH and summed feature 3 (C 16 : 1 ω 7 c and/or C 16 : 1 ω 6 c ). Menaquinone-7 was the only respiratory quinone. The major polar lipids were phosphatidylethanolamine, glycosphingolipid, aminoglycolipid/glycolipid, aminophospholipid and three or four unidentified polar lipids. These data indicated that strains SYSU D00823 T and SYSU D00873 T should be assigned to two novel species of a new genus within the family Sphingobacteriaceae , for which the names Desertivirga arenae gen. nov., sp. nov. and Desertivirga brevis sp. nov. are proposed. The type strains are SYSU D00823 T (=CGMCC 1.18630 T =MCCC 1K04973 T =KCTC 82278 T ) and SYSU D00873 T (=CGMCC 1.18629 T =MCCC 1K04974 T =KCTC 82281 T ), respectively. Accordingly, the reclassification of P. xinjiangensis as Desertivirga xinjiangensis comb. nov., and P. mongoliensis as Paradesertivirga mongoliensis gen. nov., comb. nov. are also proposed.

In the ongoing debates about eukaryogenesis-the series of evolutionary events leading to the emergence of the eukaryotic cell from prokaryotic ancestors-members of the Asgard archaea play a key part as the closest archaeal relatives of eukaryotes 1 . However, the nature and phylogenetic identity of the last common ancestor of Asgard archaea and eukaryotes remain unresolved 2-4 . Here we analyse distinct phylogenetic marker datasets of an expanded genomic sampling of Asgard archaea and evaluate competing evolutionary scenarios using state-of-the-art phylogenomic approaches. We find that eukaryotes are placed, with high confidence, as a well-nested clade within Asgard archaea and as a sister lineage to Hodarchaeales, a newly proposed order within Heimdallarchaeia. Using sophisticated gene tree and species tree reconciliation approaches, we show that analogous to the evolution of eukaryotic genomes, genome evolution in Asgard archaea involved significantly more gene duplication and fewer gene loss events compared with other archaea. Finally, we infer that the last common ancestor of Asgard archaea was probably a thermophilic chemolithotroph and that the lineage from which eukaryotes evolved adapted to mesophilic conditions and acquired the genetic potential to support a heterotrophic lifestyle. Our work provides key insights into the prokaryote-to-eukaryote transition and a platform for better understanding the emergence of cellular complexity in eukaryotic cells., (© 2023. The Author(s).)

Strain NCCP-691 T was isolated from a soil sample collected from an arid soil in Karak, Khyber Pakhtunkhwa, Pakistan. Phenotypically, the cells were Gram-stain-negative, aerobic and motile rods. The organism was able to grow between 20-40 °C (optimum at 30-37 °C), at pH 5.5-8.0 (optimum at pH 7.0-7.2) and tolerated 0-1.5% NaCl (w/v) (optimum at 0-0.5). Based on 16S rRNA gene sequences, strain NCCP-691 T formed a distinct phylogenetic clade with Noviherbaspirillum arenae , N . agri , N . denitrificans and N . autotrophicum (having sequence similarities of 99.0; 98.1; 98.0 and 97.7% respectively). Phylogenetic analyses based on the whole genome sequences confirmed that strain NCCP-691 T should be affiliated to the genus Noviherbaspirillum . The average nucleotide identity values compared to other species of Noviherbaspirillum were below 95-96 % and digital DNA-DNA hybridization values were less than 70 %. Chemotaxonomic analyses showed that the strain had ubiquinone-8, as the only respiratory quinine. The major cellular fatty acids were summed feature 3 (C 16 : 1  ω 7  c /C 16 : 1  ω 6 c, 35.9 %), summed feature 8 (C 18 : 1  ω 7  c /C 18 : 1  ω 6 c, 26.9 %) and C 16 : 0 (22.9 %) and the polar lipid profile was composed of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine. The genomic DNA G+C content was 65.5 mol% (from draft genome). Genome analyses showed that strain NCCP-691 T had terpene and arylpolyene biosynthetic genes clusters and genes related to resistance against heavy metals. Based on phylogenetic analyses, phenotypic features and genomic comparison, it is proposed that strain NCCP-691 T is a novel species of the genus Noviherbaspirillum and the name Noviherbaspirillum aridicola sp. nov. is proposed. Type strain is NCCP-691 T (=KCTC 52721 T =CGMCC 1.13600 T ).

Three closely related, facultative anaerobic, Gram-stain-negative, twitching motile, short rod-shaped, non-endospore-forming, moderately thermophilic bacteria, designated strains SYSU G05001 T , SYSU G05003 and SYSU G05004, were isolated from a hot spring microbial mat, collected from Rehai National Park, Tengchong, Yunnan Province, south-western China. The results of phylogenetic analysis based on the 16S rRNA gene sequences indicated that these three strains were closely related to Thermus scotoductus SE-1 T (97.97, 98.18, 97.90 % sequence similarity). Whole genome sequencing and polyphasic taxonomic approach were used to determine the genomic profile and taxonomic status of the novel strain SYSU G05001 T . Cell growth occurred at 37-80 °C (optimum, 55 °C), pH 6.0-8.0 (optimum, pH 7.0) and with 0-3.0 % (w/v) NaCl (optimum, 1%). Thiosulfate enhanced cell growth. MK-8 was the predominant menaquinone. The major cellular fatty acids included iso-C 15 : 0 , iso-C 17 : 0 and anteiso-C 15 : 0 . The major polar lipids were consisted of aminophospholipid, glycolipid and phospholipids. The whole genome of strain SYSU G05001 T consisted of 2.55 Mbp and the DNA G+C content was 64.94 mol%. The average nucleotide identity (≤94.95 %) and digital DNA-DNA hybridization (≤62.3 %) values between strain SYSU G05001 T and other members of the genus Thermus were all lower than the threshold values recommended for distinguishing novel prokaryotic species. On the basis of the presented polyphasic evidence and genotypic data, it is proposed that strain SYSU G05001 T (=KCTC 82627 T =MCCC 1K06118 T ) represents a novel species of the genus Thermus , for which the name Thermus brevis sp. nov. is proposed.

A novel Gram-stain-negative, aerobic, oxidase-positive, catalase-positive, non-motile, short rod-shaped, red-pigmented strain, designated as SYSU D00434 T , was isolated from a dry sandy soil sample collected from the Gurbantunggut desert in Xinjiang, north-west PR China. Strain SYSU D00434 T was found to grow at 4-37 °C (optimum, 28-30 °C), pH 6.0-8.0 (optimum, pH 7.0) and with 0-1.5 % (w/v) NaCl (optimum, 0-0.5 %). The predominant respiratory quinone was MK-7 and the major fatty acids (>10 %) were C 16 : 1  ω 5 c , iso-C 15 : 0 , summed feature 3 (C 16 : 1  ω 6 c and/or C 16 : 1  ω 7 c ) and summed feature 4 (anteiso-C 17 : 1 B and/or iso-C 17 : 1 I). The polar lipids consisted of phosphatidylethanolamine, two unidentified polar lipids, two unidentified aminolipids, two unidentified phospholipids and two unidentified glycolipids. The genomic DNA G+C content of strain SYSU D00434 T was 50.6 mol%. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain SYSU D00434 T belonged to the family Hymenobacteraceae , and shared a sequence similarity of less than 94.6 % to all validly named taxa. Based on the phenotypic, phylogenetic and chemotaxonomic properties, strain D00434 T is proposed to represent a new species of a new genus, named Sabulibacter ruber gen. nov., sp. nov., within the family Hymenobacteraceae . The type strain is SYSU D00434 T (=CGMCC 1.18624 T =KCTC 82276 T =MCCC 1K04975 T ).

Two bacterial strains, designated as SYSU D00720 T and SYSU D00722, were isolated from a desert sandy soil sample collected from Gurbantunggut Desert in Xinjiang, north-west China. Cells were Gram-stain-negative, aerobic, non-motile, rod-shaped, oxidase-positive and catalase-negative. Colonies were circular, opaque, convex, smooth, orange on Reasoner's 2A (R2A) agar. The isolates were found to grow at 4-45 °C (optimum, 28-30 °C), at pH 6.0-7.0 (optimum, 7.0) and with 0-1.5 % (w/v) NaCl (optimum, 0%). Growth was observed on R2A agar, Luria-Bertani agar and nutrient agar, but not on trypticase soy agar. The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, sphingoglycolipid, two unidentified aminolipids, one unidentified glycolipid, one unidentified aminoglycolipid, one unidentified aminophospholipid, one unidentified phospholipid and two unidentified lipids. The main fatty acids (>10%) were C 17 : 1  ω 6 c , summed feature 8 (C 18 : 1  ω 7 c and/or C 18 : 1  ω 6 c ) and C 16 : 0 . The major respiratory quinone was ubiquinone-10 and the major polyamine was sym -homospermidine. The genomic DNA G+C content was 66.0 mol%. Strains SYSU D00720 T and SYSU D00722 were nearly identical with a 16S rRNA gene sequence similarity of 99.6 %, and 100.0 % average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH) values. Phylogenetic analyses clearly demonstrated that these two strains belonged to the same species of the genus Sphingomonas , and had highest sequence similarity to Sphingomonas lutea KCTC 23642 T (97.3 %). The ANI, AAI and dDDH values of strains SYSU D00720 T and SYSU D00722 to S. lutea KCTC 23642 T were both 73.2, 69.9 and 19.2 %, respectively. Based on phylogenetic, phenotypic and chemotaxonomic distinctiveness, strains SYSU D00720 T and SYSU D00722 represent a novel species of the genus Sphingomonas , for which the name Sphingomonas arenae sp. nov. is proposed. The type strain is SYSU D00720 T (=MCCC 1K05154 T =NBRC 115061 T ).

A novel bacterium, designated TRT317 T , was isolated from saline-alkaline soil collected from the Pamir plateau in northwest China. Cells of this strain were Gram-stain-negative, aerobic rods and red-pink-coloured. Phylogenetic analysis using 16S rRNA gene sequences indicated that strain TRT317 T showed the highest sequence similarity to the type strains of Pontibacter diazotrophicus (96.3 %) and Pontibacter yuliensis (96.2 %). Growth was observed at 4-40 °C, pH 6.0-10.0 and in the presence of up to 7 % (w/v) NaCl. The major fatty acids were iso-C 15 : 0 and summed feature 4 (iso-C 17 : 1 I/anteiso-C 17 : 1 B). The polar lipids included phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified phospholipid, four unidentified glycolipids and five unidentified lipids. The whole-cell sugars of strain TRT317 T were mannose, rhamnose, glucose, galactose, xylose, arabinose and four unidentified sugars. The sole respiratory quinone was MK-7. The genomic DNA G+C content of strain TRT317 T was 47.7 mol%. The average nucleotide identity (ANI) value of strain TRT317 T with P. diazotrophicus was 88.3 %, which is below the standard ANI threshold for species identification (95-96 %). Combined results of physiological, genotypic, phylogenetic and chemotaxonomic analyses demonstrated that strain TRT317 T represents a novel species within the genus Pontibacter , for which the name Pontibacter pamirensis sp. nov. is proposed. The type strain is TRT317 T (=CGMCC1.18690 T =KCTC 82818 T ).

A Gram-stain-positive, non-motile and coccus-shaped bacterium, designated strain LNNU 331112 T , was isolated from the composite rhizosphere soil of the halophyte Suaeda aralocaspica (Bunge) Freitag and Schütze, which was collected in Xinjiang, north-west China. Growth occurred at 10-45 °C, pH 6.0-11.0 and in the presence of 0-10 % NaCl (w/v). Phylogenetic analysis based on the 16S rRNA gene sequence suggested that strain LNNU 331112 T belonged to the genus Hoyosella and showed 95.6, 95.5 and 95.4 % sequence similarities to Hoyosella altamirensis DSM 45258 T , Hoyosella subflava CGMCC 4.3532 T and Hoyosella rhizosphaerae CGMCC 1.15478 T , respectively. The estimated digital DNA-DNA hybridization relatedness values between strain LNNU 331112 T and the type strains of H. altamirensis DSM 45258 T , H. subflava CGMCC 4.3532 T and H. rhizosphaerae CGMCC 1.15478 T were 18.9, 19.3 and 18.3 %, respectively. The average nucleotide identity values between strain LNNU 331112 T and H. altamirensis DSM 45258 T , H. subflava CGMCC 4.3532 T and H. rhizosphaerae CGMCC 1.15478 T were 72.6, 72.7 and 72.3 %, respectively. The genome sequence of strain LNNU 331112 T showed 69.0-72.3 % average amino acid identity values in comparison with the related genome sequences of three validly published Hoyosella species. The genome of strain LNNU 331112 T was 3.47 Mb, with a DNA G+C content of 68.4 mol%. A total of 3182 genes were identified as protein-coding in strain LNNU 331112 T . Genomic analysis revealed that a number of genes involved in osmotic pressure regulation, intracellular pH homeostasis and potassium (K + ) uptake protein were found in strain LNNU 331112 T . The predominant menaquinones were MK-8 (44.6 %) and MK-7 (55.4 %), which differentiated strain LNNU 331112 T from other three recognized Hoyosella species. Major fatty acids (>10 %) were C 17 : 1  ω8 c (33.8 %), C 16 : 0 (23.3 %), C 17 : 0 (12.8 %) and summed feature 3 (12.9 %), which also clearly separated strain LNNU 331112 T from three recognized Hoyosella species. The polar lipid profile of strain LNNU 331112 T included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, one unidentified glycolipid, one unidentified phospholipid and two unidentified lipids. According to the results of phenotypic, chemotaxonomic and phylogenetic analyses, strain LNNU 331112 T is considered to represent a novel species of the genus Hoyosella , for which the name Hoyosella suaedae sp. nov. is proposed. The type strain is LNNU 331112 T (=KCTC 39808 T =CGMCC 1.17107 T =DSM 103463 T ).

A bacterial strain, designated YZGR15 T , was isolated from the root of an annual halophyte Suaeda aralocaspica , collected from the southern edge of the Gurbantunggut desert, north-west PR China. Cells of the isolate were Gram-stain-positive, facultatively anaerobic, irregular rods. Growth occurred at 4-42 °C (optimum, 30-37 °C), at pH 6.0-9.0 (optimum, pH 7.0-7.5) and in the presence of 0-9 % (w/v) NaCl (optimum, 2-5 %). Phylogenetic analysis using 16S rRNA gene sequences indicated that strain YZGR15 T showed the highest sequence similarity to Sanguibacter keddieii (98.27 %) , Sanguibacter antarcticus (98.20 %) and Sanguibacter inulinus (98.06 %). Results of genome analyses of strain YZGR15 T indicated that the genome size was 3.16 Mb, with a genomic DNA G+C content of 71.9 mol%. Average nucleotide identity and digital DNA-DNA hybridization values between strain YZGR15 T and three type strains were in the range of 76.5-77.8 % and 20.0-22.2 %, respectively. Analysis of the cellular component of strain YZGR15 T revealed that the primary fatty acids were anteiso-C 15 : 0 , C 16 : 0 , C 14 : 0 and iso-C 16 : 0 and the polar lipids included diphosphatidylglycerol, phosphatidylglycerol, three unidentified phospholipids and two unidentified glycolipids. The cell-wall characteristic amino acids were glutamic acid, alanine and an unknown amino acid. The whole-cell sugars for the strain were mannose, ribose, rhamnose, glucose and an unidentified sugar. The predominant respiratory quinone was MK-9(H 4 ). Based on the results of genomic, phylogenetic, phenotypic and chemotaxonomic analyses, strain YZGR15 T represents a novel species of the genus Sanguibacter , for which the name Sanguibacter suaedae sp. nov. is proposed. The type strain is YZGR15 T (=CGMCC 1.18691 T =KCTC 49659 T ).

A novel actinobacterium, designated strain SYSU M44304 T , was isolated from freshwater samples in the Pearl River Estuary. The isolate was Gram-stain-positive, aerobic, coccus-shaped, oxidase-positive and motile. The cell wall contained meso -diaminopimelic acid as its diagnostic diamino acid. The predominant menaquinone was MK-8. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine and seven unidentified phospholipids. The major fatty acids were C 16 : 0 and C 16 : 1 . The G+C content based on genomic DNA was 73.2 mol %. The nearest phylogenetic neighbours to the novel strain were Mobilicoccus pelagius NBRC 104925 T and Mobilicoccus caccae YIM 101593 T . On the basis of chemotaxonomic and physiological characteristics and phylogenetic analysis, strain SYSU M44304 T should be considered to represent a novel species of a new genus in the family Dermatophilaceae , for which we propose the name Agilicoccus flavus gen. nov., sp. nov. The type strain of Agilicoccus flavus is SYSU M44304 T (=NBRC 114808 T =CGMCC 1.18608 T ).

The taxonomic positions of members within the family Pseudonocardiaceae were assessed based on phylogenomic trees reconstructed using core-proteome and genome blast distance phylogeny approaches. The closely clustered genome sequences from the type strains of validly published names within the family Pseudonocardiaceae were analysed using overall genome-related indices based on average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values. The family Pseudonocardiaceae consists of the type genus Pseudonocardia , as well as the genera Actinoalloteichus , Actinocrispum , Actinokineospora , Actinomycetospora , Actinophytocola , Actinopolyspora , Actinorectispora , Actinosynnema , Allokutzneria , Allosaccharopolyspora gen. nov., Amycolatopsis , Bounagaea , Crossiella , Gandjariella , Goodfellowiella , Haloactinomyces , Haloechinothrix , Halopolyspora , Halosaccharopolyspora gen. nov., Herbihabitans , Kibdelosporangium , Kutzneria , Labedaea , Lentzea , Longimycelium , Prauserella , Saccharomonospora , Saccharopolyspora , Saccharothrix , Salinifilum , Sciscionella , Streptoalloteichus , Tamaricihabitans , Thermocrispum , Thermotunica and Umezawaea . The G+C contents of the Pseudonocardiaceae genomes ranged from 66.2 to 74.6 mol% and genome sizes ranged from 3.69 to 12.28 Mbp. Based on the results of phylogenomic analysis, the names Allosaccharopolyspora coralli comb. nov., Halosaccharopolyspora lacisalsi comb. nov. and Actinoalloteichus caeruleus comb. nov. are proposed. This study revealed that Actinokineospora mzabensis is a heterotypic synonym of Actinokineospora spheciospongiae , Lentzea deserti is a heterotypic synonym of Lentzea atacamensis , Prauserella endophytica is a heterotypic synonym of Prauserella coralliicola , and Prauserella flava and Prauserella sediminis are heterotypic synonyms of Prauserella salsuginis . This study addresses the nomenclature conundrums of Actinoalloteichus cyanogriseus and Streptomyces caeruleus as well as Micropolyspora internatus and Saccharomonospora viridis .

A novel species of the genus Roseomonas , designated SYSU M41301 T , was isolated from water sample of the Pearl River estuary in Guangdong, China. Polyphasic, taxonomic and phylogenomic analyses were used to determine the taxonomy position of the strain. Phylogenetic analysis using 16S rRNA gene sequence indicated that strain SYSU M41301 T showed the highest sequence similarity to Roseomonas stagni KCTC 22213 T (97.9 %) and Roseomonas riguiloci KCTC 23339 T (96.4 %). The novel species could be differentiated from other species of the genus Roseomonas by its distinct phenotypic and genotypic characteristics. The isolate was Gram-staining-negative, aerobic, short rod-shape, oxidase-positive and non-motile. The predominant respiratory quinone was ubiquinone 8 (Q-8). The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, and one unidentified polar lipid. The major fatty acids (>10 % of total) were 11-methyl C 18 : 1  ω 7 c , summed feature 3 (C 16 : 1  ω7 c and / or C 16 : 1  ω6 c) and summed feature 8 (C 18:  :1  ω 7 c and/or C 18 : 1  ω 6 c ). The G+C content of the novel isolate based on genomic DNA was 72.0 mol%. On the basis of phenotypic, genotypic and phylogenetic data, strain SYSU M41301 T should be considered to represent a novel species in the genus Roseomonas, for which the name Roseomonas ponticola sp. nov. is proposed with the type strain SYSU M41301 T (=KCTC 72726 T =CGMCC 1.18613 T ).

Two Gram-stain-negative, motile, facultatively anaerobic, rod-shaped strains, FJAT-53720 T and FJAT-53726, were isolated from rhizosphere sediment of plant Cyperus malaccensis . Phylogenetic analysis based on their 16S rRNA gene sequences revealed that strains FJAT-53720 T and FJAT-53726 were affiliated to the genus Shewanella (forming an independent cluster) with the highest sequence similarity to the type strain of Shewanella algae . Optimum growth of both strains was observed at 30 °C and pH 7. The respiratory quinones were Q-7, Q-8 and MK-7. The polar lipid profile included phosphatidylmethyl ethanolamine, phosphatidylethanolamine, diphosphatidylglycerol, one unidentified aminophospholipid and four unknown phospholipids. The major fatty acids of strains FJAT-53720 T and FJAT-53726 were iso-C 15:0, C 17 : 1 ω 8 c and summed feature 3. The genomic DNA G+C content of strain FJAT-53720 T was 55.6 mol%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between FJAT-53720 T and FJAT-53726 were 97.4 and 77.9 %, confirming that they were similar species and hence FJAT-53720 T was selected for further analysis. The ANI and dDDH values between FJAT-53720 T and other members of the genus Shewanella were below the cut-off level (95-96 %; 70 %) for species delineation. Based on the above results, FJAT-53720 T represents a novel species of the genus Shewanella , for which the name Shewanella cyperi sp. nov. is proposed. The type strain is FJAT-53720 T (=KCTC 82444 T =GDMCC 1.2207 T ).

The present study was carried out to re-clarify the taxonomic relationship of Caldicellulosiruptor acetigenus , Caldicellulosiruptor lactoaceticus and Caldicellulosiruptor kristjanssonii . The 16S rRNA sequence similarities between these species of the genus Caldicellulosiruptor were above the threshold values (98.65%) for bacterial species delineation. Similarly, the digital DNA-DNA hybridization and average nucleotide and amino acid identity values were greater than the thresholds for bacterial species delineation. In phylogenetic (based on 16S rRNA gene sequences) and phylogenomic trees Caldicellulosiruptor acetigenus , Caldicellulosiruptor lactoaceticus and Caldicellulosiruptor kristjanssonii clade together. The results of our analysis indicated that these three taxa are conspecific. Therefore, Caldicellulosiruptor lactoaceticus Mladenovska et al . 1997 and Caldicellulosiruptor kristjanssonii Bredholt et al . 1999 should be reclassified as later heterotypic synonyms of Caldicellulosiruptor acetigenus (Nielsen et al . 1994) Onyenwoke et al . 2006.

A novel Gram-stain-positive, catalase-positive, oxidase-negative, aerobic, non-motile, rod-shaped bacterium, designated strain YIM M12148 T , was isolated from a marine sediment sample collected from the Indian Ocean. The strain grew optimally at 28 °C, pH 8.0 and in the presence of 1-3 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM M12148 T belongs to the genus Gulosibacter , with the highest sequence similarity to Gulosibacter faecalis NBRC 15706 T (96.12 %). The cell-wall sugars of strain YIM M12148 T were rhamnose, ribose, glucose and mannose. The predominant isoprenoid quinones were MK-8 and MK-9. The polar lipids consisted of major amounts of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unknown phospholipid and one unknown lipid. Major fatty acids (>5 % of the total) of the novel isolate were anteiso-C 15 : 0 , iso-C 15 : 0 , iso-C 13 : 0 and anteiso-C 13 : 0 . The genomic DNA G+C content of strain YIM M12148 T was 67.15 mol%. On the basis of genotypic and phenotypic data, it is apparent that strain YIM M12148 T represents a novel species of the genus Gulosibacter , for which the name Gulosibacter sediminis sp. nov. is proposed. The type strain is YIM M12148 T (=KCTC 29660 T =DSM 29154 T ).

A novel pale orange-coloured bacterium, designated strain SYSU D00532 T , was isolated from sandy soil collected from the Gurbantunggut desert in Xinjiang, PR China. Cells of strain SYSU D00532 T were found to be aerobic, Gram-stain-negative, oxidase-positive, catalase-positive, motile and rod-shaped with a single polar or subpolar flagellum. Growth occurred at 15-45 °C (optimum, 28-37 °C, pH 5.0-8.0 (optimum, pH 6.0-7.0) and with 0-1.5% NaCl (w/v; optimum, 0.5 %). The major polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and phosphatidylglycerol. Unidentified aminolipids, unidentified polar lipids, an unidentified aminophospholipid and an unidentified phospholipid were also detected. The major respiratory quinone was ubiquinone-10 and the major fatty acids were summed feature 8 (C 18:1 ω 7 c and/or C 18:1 ω 6 c ), C 16:0 and C 19:0 cyclo ω 8 c . The genomic DNA G+C content was 69.8 mol%. Results of phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SYSU D00532 T belonged to the family Azospirillaceae and showed 93.4% ( Desertibacter roseus 2622 T ), 93.2% ( Skermanella xinjiangensis 10-1-101 T ), 93.2% (' Skermanella rubra ' YIM 93097 T ) and 92.4% ( Desertibacter xinjiangensis M71 T ) similarities. Based on the phylogenetic, phenotypic and chemotaxonomic data, strain SYSU D00532 T is proposed to represent a new species of a new genus, named Arenibaculum pallidiluteum gen. nov., sp. nov., within the family Azospirillaceae . The type strain is SYSU D00532 T (=KCTC 82269 T =CGMCC 1.18631 T =MCCC 1K04984 T ). We also propose the reclassification of Skermanella xinjiangensis to a new genus Deserticella as Deserticella xinjiangensis comb. nov., and the transfer of the genera Indioceanicola and Oleisolibacter from the family Rhodospirillaceae to the family Azospirillaceaewe based on the phylogenetic results.

Geothermal environments, such as hot springs and hydrothermal vents, are hotspots for carbon cycling and contain many poorly described microbial taxa. Here, we reconstructed 15 archaeal metagenome-assembled genomes (MAGs) from terrestrial hot spring sediments in China and deep-sea hydrothermal vent sediments in Guaymas Basin, Gulf of California. Phylogenetic analyses of these MAGs indicate that they form a distinct group within the TACK superphylum, and thus we propose their classification as a new phylum, 'Brockarchaeota', named after Thomas Brock for his seminal research in hot springs. Based on the MAG sequence information, we infer that some Brockarchaeota are uniquely capable of mediating non-methanogenic anaerobic methylotrophy, via the tetrahydrofolate methyl branch of the Wood-Ljungdahl pathway and reductive glycine pathway. The hydrothermal vent genotypes appear to be obligate fermenters of plant-derived polysaccharides that rely mostly on substrate-level phosphorylation, as they seem to lack most respiratory complexes. In contrast, hot spring lineages have alternate pathways to increase their ATP yield, including anaerobic methylotrophy of methanol and trimethylamine, and potentially use geothermally derived mercury, arsenic, or hydrogen. Their broad distribution and their apparent anaerobic metabolic versatility indicate that Brockarchaeota may occupy previously overlooked roles in anaerobic carbon cycling.

An alkaliphilic actinobacterial strain, designated Hz 6-5 T , was isolated from saline-alkaline soil from Songnen Plain in north-eastern China. The isolate formed light yellow-colored colonies and its cells were Gram-staining positive, non-motile, and non-spore-forming short rods. The strain was aerobic with optimal growth at 33 °C, pH 9.0, and in the presence of 0.5% (w/v) NaCl or 3% (w/v) KCl. It was catalase-positive and oxidase-negative. The isolate had highest 16S rRNA gene sequence similarities to the type strains of the species Nesternkonia natronophila M8 T (98.2%), N. salmonea GY074 T (98.1%), and N. sphaerica GY239 T (97.4%), and the isolate formed a subclade with the type strains of these species in the neighbor-joining tree based on the 16S rRNA gene sequences. The phylogenetic tree based on the phylogenomic analysis also showed the same results. The DNA‒DNA relatedness (DDH) values of isolate Hz 6-5 T with N. natronophila M8 T , N. halophila DSM 16378 T , and N. halobia CGMCC 1.2323 T were 21.2%, 36.5%, and 32.0%, respectively. The characteristic diamino acid of strain Hz 6-5 T was found to be lysine. The respiratory quinones were MK-9, MK-8, MK-7(H 4 ), MK-7(H 2 ) and MK-7 and the major cellular fatty acids (> 10%) were anteiso-C 15:0 , anteiso-C 17:0 and iso-C 16:0 . The polar lipids detected for strain Hz 6-5 T were diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol, an unidentified glycolipid, and two unidentified phospholipids. The DNA G + C content of isolate Hz 6-5 T was 60.8%. Based on the results of phylogenetic analysis supported by morphological, physiological, chemotaxonomic, and other differentiating phenotypic evidence, strain Hz 6-5 T is considered to represent a novel species of the genus Nesterenkonia, for which the name Nesterenkonia haasae sp. nov. is proposed. The type strain is Hz 6-5 T (=CPCC 205100 T =NBRC 113521 T ).

A non-motile, Gram-staining negative, catalase- and oxidase-positive, crescent-rod shaped bacterium, designated strain CUG 91308 T , was isolated from a sediment sample of Qinghai Lake, Qinghai Province, China. Colonies on OSM agar were round, smooth, flat and pinkish-orange in colour. Strain CUG 91308 T could grow at 15-37 °C, pH 6-12 and in the presence of up to 7.0 % NaCl (w/v). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CUG 91308 T belonged to the family Cyclobacteriaceae and formed a clade with the genus Lunatimonas in the phylogenetic tree, but separated from any species of the known genera within the family. The genomic DNA G+C content is about 42.1 %. The predominant fatty acids (>10 %) were iso-C 15 : 0 (21.1 %), summed feature 3 (C 16 : 1   ω 7c / C 16 : 1   ω 6c / iso-C 15 : 0 2OH) (14.3 %), iso-C 17 : 0 3OH (12.3 %) and summed feature 9 (iso-C 17 : 1   ω 9c / C 16 : 0 10-methyl) (10.6 %). The polar lipids of strain CUG 91308 T were phosphatidylethanolamine (PE) and four unidentified polar lipids. Strain CUG 91308 T contained MK-7 as the major respiratory quinone. On the basis of phenotypic, genotypic and phylogenetic data, strain CUG 91308 T represents a novel species of a novel genus in the family Cyclobacteriaceae , for which the name Lunatibacter salilacus gen. nov., sp. nov. is proposed. The type strain of the proposed new isolate is CUG 91308 T (=KCTC 62636 T =CGMCC 1.13593 T ).

Two anaerobic bacteria, designated strains SYSU GA16112 T and SYSU GA16107, were isolated from a hot spring in Tengchong County, Yunnan Province, south-west PR China. Phylogenetic analyses based on 16S rRNA gene sequences showed that strains SYSU GA16112 T and SYSU GA16107 belong to the family Dysgonamonadaceae . Cells of strains SYSU GA16112 T and SYSU GA16107 were Gram-stain-negative, rod-shaped and non-motile. The major fatty acids (>10 %) of strains SYSU GA16112 T and SYSU GA16107 were identified as anteiso-C 15 : 0 and anteiso-C 17 : 0 3OH. The polar lipid profile of strain SYSU GA16112 T was found to consist of phosphatidylethanolamine, two unidentified aminophospholipids, two unidentified phosphoglycolipids, two unidentified aminolipids and one unidentified polar lipid, while that of strain SYSU GA16107 consisted of phosphatidylethanolamine, two unidentified polar lipids, three unidentified aminophospholipids, two unidentified phosphoglycolipids and one unidentified aminolipid. The genomic DNA G+C contents of strains SYSU GA16112 T and SYSU GA16107 were determined to be 41.90 and 41.89 %, respectively, and the average nucleotide identity value between them was 99.99 %. Based on their morphological and physiological properties, and results of phylogenetic analyses, strains SYSU GA16112 T and SYSU GA16107 are considered to represent a novel species of a novel genus, for which the name Seramator thermalis gen. nov., sp. nov. (type strain SYSU GA16112 T =CGMCC 1.5281 T =KCTC 15753 T ) is proposed.

One motile strain designated, YIM DR1026 T was isolated from the roots of Psammosilene tunicoides collected from Gejiu, Yunnan province, China. The cells of strain YIM DR1026 T were Gram-negative and short-rod shaped. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain YIM DR1026 T was a member of the genus Aureimonas and closely related to Aureimonas rubiginis (96.7%). DNA-DNA relatedness values between strain YIM 1026 T and Aureimonas rubiginis BCRC 80440 T was 38.2 ± 1.5%. The ANI value between YIM DR1026 T and other Aureimonas members were below the cut-off level (95-96%) recommended as the average nucleotide identity (ANI) criterion for interspecies identity. Strain YIM DR1026 T grew at 4-30 °C (optimum 28 °C), pH 4.0-9.0 (optimum pH 6.0-7.0) and tolerated NaCl (w/v) up to 1% (optimum 0%). Q-10 was sole the respiratory ubiquinone present in YIM DR1026 T . Polar lipids of strain YIM DR1026 T were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine, sulfoquinovosyldiacylglycerol, unidentified aminolipid and unidentified polar lipid. The genomic G + C content was 64.6 mol%. The major fatty acids were C 18:1 ω7c, C 16:0 and summed feature 3 (C 16:1ω 7c/C 16:1ω 6c). Based on phenotypic, phylogenetic, chemotaxonomic and genome comparison, strain YIM DR1026 T represents a novel species of the genus Aureimonas, for which the name Aureimonas psammosilene sp. nov. is proposed. The type strain is YIM DR1026 T (= KCTC 42691 T  = NBRC 112412 T ).

Two novel Gram-stain negative, moderately thermophilic, aerobic, rod-shaped strains, designated 3D203 T and 3D207, were isolated from hot spring sediment samples collected from Tibet, western China. Phylogenetic analyses based on 16S rRNA gene sequence similarities showed that two isolates belonged to the genus Microvirga and were most closely related to Microvirga makkahensis SV1470 T (98.5% and 98.4%, respectively) and two strains had 99.8% similarity to each other. The average nucleotide identity (ANI) based on whole genome sequences of two strains and M. makkahensis SV1470 T was 80.8% and 80.78%, respectively. Optimum growth was observed at 45 °C, pH 7.0 and 0.5% NaCl. They both could tolerate to high concentration arsenic. Ubiquinone 10 (Q10) was their predominant quinone. The differences of strains 3D203 T and 3D207 were phosphatidyl dimethyl ethanolamine, phosphatidyl-N-methylethanolamine, phosphatidylglycerol, unidentified glycolipids and unidentified lipids. The major fatty acids (> 5%) were identified C 18:1 ω7c and/or C 18:1 ω6c, C 18:0 and C 16:0 . The genomic DNA G + C contents of strain 3D203 T and 3D207 based on whole genome sequences were 64.8% and 64.7%, respectively. Phenotypic, chemotaxonomic, phylogenetic and genomic analyses suggested that two strains represent a novel species of the genus Microvirga, for which the name Microvirga arsenatis sp. nov. is proposed. The type strain is 3D203 T (= CGMCC 1.17691 T  = KCTC 72653 T ).

A Gram-stain-negative, rod-shaped bacterium, designated XJ4 T , was isolated from oil-contaminated water, collected from Xinjiang Province, north-west PR China (45° 1' 27″ N, 85° 6' 14″ E). Growth occurred at 20-45 °C (optimum, 30 °C) and pH 6.0-10.0 (optimum, pH 6.0-7.0). Strain XJ4 T could tolerate up to 7 % (w/v) NaCl and grow optimally in the absence of NaCl. Phylogenetic analysis based on comparative sequence analysis of 16S rRNA gene sequences indicated that strain XJ4 T belonged to the genus Frigidibacter , and that was closely related to Frigidibacter mobilis cai42 T (97.2 %), Frigidibacter albus SP32 T (97.0 %) and Rhodobacter aestuarii JA296 T (97.0 %). The average nucleotide identity values between XJ4 T and three type strains were 77.9, 77.6 and 71.9 %, respectively. The DNA G+C content of strain XJ4 T was 69.5 mol%. The sole respiratory quinone was Q-10. The major cellular fatty acid was summed feature 8 (C 18 : 1   ω7 c and/or C 18 : 1   ω6 c ), C 18 : 0 and 11-methyl C 18 : 1   ω7 c . The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, unidentified phospholipids, an unidentified aminolipid and unidentified lipids. On the basis of phenotypic, chemotaxonomic and phylogenetic analyses, strain XJ4 T represents a novel species of the genus Frigidibacter , for which the name Frigidibacter oleivorans sp. nov. is proposed. The type strain is XJ4 T (=CGMCC 1.13778 T =LMG 30952 T ).

Two novel strains, designated SYSU L10167 T and SYSU L10180 T , were isolated from sediment sampled at Dabancheng saline lake in Xinjiang, PR China. A polyphasic approach was used to clarify the taxonomic positions of the two strains. Cells of the isolates were curved ring-like, horseshoe-shaped or rod-shaped, non-motile and non-spore-forming. Cells were Gram-stain-negative, aerobic, heterotrophic and rose-pigmented. The phylogenetic trees based on 16S rRNA gene sequences showed that strains SYSU L10167 T and SYSU L10180 T formed a distinct lineage within the genus Cyclobacterium . Strains SYSU L10167 T and SYSU L10180 T showed highest similarities to Cyclobacterium jeungdonense KCTC 23150 T (98.0 and 97.4%, respectively). Results of genomic analyses (including average nucleotide identity, digital DNA-DNA hybridization and the marker gene tree) and pan-genome analysis further confirmed that strains SYSU L10167 T and SYSU L10180 T were separate from each other and other species of the genus Cyclobacterium . The draft genomes of the isolates had sizes of 5.5-5.7 Mb and reflected their major physiological capabilities. Based on phenotypic, physiological, chemotaxonomic and genotypic characterization, we propose that the isolates represent two novel species, for which the names Cyclobacterium salsum sp. nov. and Cyclobacterium roseum sp. nov. are proposed. The type strains of the species are SYSU L10167 T (=KCTC 72390 T =CGMCC 1.17521 T ) and SYSU L10180 T (=KCTC 72391 T =CGMCC 1.17278 T ).

A Gram-stain-positive, facultatively anaerobic and non-motile strain, designated SYSUP0004 T , was isolated from the tubers of Gastrodia elata Blume collected from Yunnan Province, PR China. The 16S rRNA gene sequence result showed that the strain SYSUP0004 T shared low similarity (97.7 %) with the type strain of Cellulomonas marina . SYSUP0004 T grew at pH 6.0-9.0 (optimum, pH 8.0), temperature 4-30 °C (optimum, 28 °C) and could tolerate NaCl up to 4 % w/v (optimum in the absence of NaCl). The cell-wall peptidoglycan type was A4 β with an interpeptide bridge l-ornithine-d-glutamic acid. Cell-wall sugars were mannose, ribose, glucose, galactose and fucose. The menaquinone was MK-9(H 4 ). The major fatty acids were anteiso-C 15:0, anteiso-C 15 : 1 A, C 16 : 0 and anteiso-C 17 : 0 . The polar lipids of SYSUP0004 T were diphosphatidylglycerol, unidentified phosphoglycolipid, phosphatidylinositol mannosides and unidentified glycolipid. The genomic DNA G+C content was 76.5 %. The average nucleotide identity values between SYSUP0004 T and members of the genus Cellulomonas were below the cut-off level (95-96 %) recommended as the ANI criterion for interspecies identity. Thus, based on the above results strain SYSUP0004 T represents a novel species of the genus Cellulomonas , for which the name Cellulomonas endophytica sp. nov. is proposed. The type strain, SYSUP0004 T (=KCTC 49025 T =CGMCC 1.16405 T ).

A novel endophytic actinobacterium, designated strain EGI 650086 T , was isolated from the roots of Anabasis elatior (C.A.Mey.) Schischk. collected in Xinjiang, north-west China. The taxonomic position of the strain was investigated using a polyphasic taxonomic approach. Growth occurred at 15-40 °C, pH 6.0-8.0 and in the presence of 0-6 % NaCl (w/v). Phylogenetic analysis based on 16S rRNA gene sequence and concatenation of 22 protein marker genes revealed that strain EGI 650086 T formed a monophyletic clade within the genus Amycolatopsis and shared the highest sequence similarities with Amycolatopsis nigrescens JCM 14717 T (97.1 %) and Amycolatopsis sacchari DSM 44468 T (97.0 %). Sequence similarities with type strains of other species of the genus Amycolatopsis were less than 97.0 %. The average nucleotide identity and DNA-DNA hybridization values between strain EGI 650086 T and the reference strains were 78.1-79.8 % and 22.1-23.0 %, respectively. The genome of strain EGI 650086 T was 10.9 Mb, with a DNA G+C content of 70.1 mol%. The diagnostic diamino acid in the peptidoglycan was meso -diaminopimelic acid. The major whole-cell sugars contained arabinose, galactose, glucose and ribose. The predominant menaquinones were MK-9 (H 4 ) and MK-9 (H 2 ). Major fatty acids were iso -C 16 : 0 and summed feature 4 ( iso -C 17 : 1 I and/or anteiso -C 17 : 1 B). The polar lipid profile of strain EGI 650086 T included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannosides, two unknown phospholipids, an unknown glycolipid and an unknown lipid. Polyphasic taxonomic characteristics indicated that strain EGI 650086 T represents a novel species of the genus Amycolatopsis , for which the name Amycolatopsis anabasis sp. nov. is proposed. The type strain is EGI 650086 T (=KCTC 49044 T =CGMCC 4.7188 T ).

A novel Gram-staining-negative, spiral-shaped bacterium, designated strain 64-1 T , was isolated from oil reservoir water collected from Liaohe oilfield, north-eastern China. Growth occurred at 15-55 °C and pH 6.0-10.0. The sole respiratory quinone was Q-10. The predominant cellular fatty acids were summed feature 8 (C 18 : 1  ω 7 c /C 18 : 1  ω 6 c ), C 16 : 0 and C 19 : 0 cyclo ω 8 c . The polar lipids consisted of phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylcholine (PC), an unidentified aminophospholipid (UAPL), an unidentified aminolipid (UAL) and two unidentified polar lipids (UPL). The genomic DNA G+C content of strain 64-1 T was 64.5 mol%. Strain 64-1 T shared the highest 16S rRNA gene sequence similarities with Phaeospirillum chandramohanii JA145 T (92.0 %) and Telmatospirillum siberiense 26-4b1 T (91.8 %). In the phylogenetic trees, the strain constituted a sub-cluster within the family Rhodospirillaceae . Based on the results of morphological, physiological, biochemical and phylogenetic analysis, strain 64-1 T represents a new species of a novel genus within the family Rhodospirillaceae , for which the name Oleiliquidispirillum nitrogeniifigens gen. nov., sp. nov. is proposed. The type strain is 64-1 T (=CGMCC 1.16798 T =LMG 31399 T ).

Four strains (SYSU SYW-1 T , SYW-2, SYW-3 and XLW-1) were isolated from seawater near the shore in Guangdong Province, China. Cells were Gram-stain-negative, aerobic, non-motile and non-spore-forming. Growth was observed at a temperature range of 16-40 °C (optimum, 32 °C), a pH range of 4-8 (optimum, pH 7) and in the presence of up to 10 % (w/v) NaCl. The major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine and an unidentified phospholipid. The respiratory quinone was ubiquinone 8 (UQ-8), and the predominant fatty acids were C 18 : 0 3-OH, C 10 : 0 , C 14 : 0 and C 18 : 1 ω9 c . Comparison of 16S rRNA gene and genome sequences confirmed that these strains represented a novel member of the genus Francisella , with less than 98.8 % 16S rRNA gene sequence similarity and less than 95 % genomic average nucleotide identity to recognized Francisella species. The phylogenetic tree based on 16S rRNA gene sequences and the protein-concatamer tree based on a concatenation of 28 protein marker sequences both indicated that the strains clustered with ' Francisella salina ' TX07-7308 and ' Francisella marina ' E95-16, but formed a distinct lineage group among the other members of the genus Francisella . The DNA G+C contents of the four strains were determined to be 32.9, 32.7, 32.9 and 32.9 %, respectively (genome). On the basis of phenotypic and genotypic features, the strains are considered to represent a novel species of the genus Francisella , for which the name Francisella salimarina sp. nov. is proposed. The type strain is SYSU SYW-1 T (=CGMCC 1.17031 T =NBRC 113781 T ).

A Gram-stain-positive, motile, rod-shaped and endospore-forming strain, SYSU K30002 T , was isolated from a soil sample collected from a karst cave in Xingyi county, Guizhou province, south-west China. SYSU K30002 T grew at 28-40 °C (optimum, 37 °C), at pH 5.0-8.0 (optimum, pH 7.0) and in the presence of 0-4 % (w/v) NaCl (optimum in the absence of NaCl). The cell-wall peptidoglycan type was A4 α (Lys-Asp). The cell-wall sugars of SYSU K30002 T were ribose, galactose and mannose, and MK-7 was the menaquinone. The major fatty acids were iso-C 15 : 0 , C 16 : 1 ω 7 c alcohol and iso-C 16 : 0 . The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and two unidentified phospholipids. The G+C content of the genomic DNA was 36.1 mol%. The average nucleotide identity values between SYSU K30002 T and its closest relatives were below the cut-off level (95-96 %) for species delineation. Based on phenotypic, chemotaxonomic and genome comparisons, strain SYSU K30002 T represents a novel species of the genus Lysinibacillus , for which the name Lysinibacillusantri sp. nov. is proposed. The type strain is SYSU K30002 T (=KCTC 33955 T =CGMCC 1.13504 T ).

A novel thermotolerant bacterial strain was isolated from a hot spring in a Tibetan geothermal field. Phylogenetic analysis of the 16S rRNA gene sequence of the novel strain showed that it belongs to a distinct lineage far from any known taxa. The new isolate shared the highest pairwise sequence identity with Phreatobacter cathodiphilus S-12 T (92.8 % similarity) according to the 16S rRNA gene sequences. Cells were Gram-stain-negative, aerobic, rod-shaped and formed white round colonies. The strain grew at the ranges of 28-45 °C (optimum, 37 °C), pH 5.0-7.0 (optimum, pH 6.0) and 0-2 % NaCl. The strain was positive for catalase and oxidase. The major respiratory quinone was ubiquinone Q-10. Polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine. The major fatty acids were summed feature 8 (C 18 : 1   ω7 c and/or C 18 : 1   ω6 c ). The DNA G+C content was 68.3 mol%. Based on these distinguishing properties, this strain is proposed to represent a new species of a new genus Rhabdaerophilum calidifontis gen. nov., sp. nov., within a new family Rhabdaerophilaceae fam. nov. The type strain of the type species of Rhabdaerophilum calidifontis is SYSU G02060 T (=KCTC 72351 T =CGMCC 1.17070 T ).

A coccobacilli-shaped proteobacterium, designated strain SYSU XM001 T , was isolated from an activated sludge sample collected from JiMei sewage treatment plant, Xiamen, PR China. Cells were Gram-stain-negative, catalase-positive and oxidase-negative. The 16S rRNA gene sequence of strain SYSU XM001 T shared less than 92 % sequence identities with members of the class Alphaproteobacteria , with highest sequence similarity to Aquidulcibacter paucihalophilus TH1-2 T (91.6 %; family Hyphomonadaceae , order Rhodobacterales ). The strain exhibited growth at 25-37 °C, pH 7.0-9.0 and in the presence of up to 1 % (w/v) NaCl. Its chemotaxonomic features included ubiquinone-10 as the respiratory isoprenologue, iso-C 16 : 0 , 10-methyl C 16 : 0 TSBA and anteiso-C 17 : 0 as major cellular fatty acids and monoglycosyldiglyceride, glucuronopyranosyldiglyceride and two unidentified glycolipids as the main polar lipids. The DNA G+C content was determined to be 62.9 % (draft genome). Analyses of the phylogenetic data and differences in the chemotaxonomic and biochemical features from related genera in the family Hyphomonadaceae indicated that strain SYSU XM001 T merits representation of a novel species of a novel genus, for which the name Vitreimonas flagellata gen. nov., sp. nov. is proposed. The type strain of Vitreimonas flagellata is SYSU XM001 T (=CGMCC 1.16661 T =KCTC 62915 T ).

A novel bacterium, designated strain SYSU M00256-3 T , was isolated from a water sample collected from Pearl River Estuary at Guangzhou, PR China. Its taxonomic position was determined by using a polyphasic approach. Cells of the strain were Gram-staining-negative, motile, aerobic and rod-shaped with peritrichous flagella. It could grow at 15-45 °C, pH 4.0-10.0 and in the presence of 0-7.5 % (w/v) NaCl. The chemotaxonomic features of strain SYSU M00256-3 T included ubiquinone-10 (Q-10) as the sole respiratory quinone; phosphatidylcholine, phosphatidylmethylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid as major polar lipids; summed feature 8 (C 18 : 1   ω 7c and C 18 : 1  ω 6 c ) as the predominant fatty acids (>70 %). On the basis of 16S rRNA gene sequence analysis, strain SYSU M00256-3 T was most closely related to the type strains of Roseibium hamelinense CGMCC 1.12584 T (97.7 %) and R. aquae CGMCC 1.12426 T (97.2 %), R. sediminis KCTC 52373 T (96.7 %), R. denhamense CGMCC 1.12583 T (96.4 %). The average nucleotide identity (ANI) values between R. aestuarii SYSU M00256-3 T and R. hamelinense CGMCC 1.12584 T , R. aquae CGMCC 1.12426 T , R. denhamense CGMCC 1.12583 T and R. sediminis KCTC 52373 T were 78.0, 78.2, 77.7 and 78.8, and the dDDH value is 20.0, 20.8, 20.1 and 20.6 correspondingly. Based on the analyses of the phenotypic, genotypic and phylogenetic characteristics, strain SYSU M00256-3 T is characterized to represent a novel species of the genus Roseibium , for which the name Roseibium aestuarii sp. nov. is proposed. The type strain is SYSU M00256-3 T (=NBRC 112946 T =CGMCC 1.16156 T ).