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Strain WL0113 T was isolated from surface seawater of the coast of Lianyungang, Jiangsu province, PR China. Strain WL0113 T shared highest 16S rRNA gene sequence similarity with Roseobacter insulae YSTF-M11 T (98.8%), followed by R. cerasinus AI77 T (98.8%), R. ponti MM-7  T (98.0%). Strain WL0113 T was Gram-stain-negative, cream, aerobic, non-motile and coccoid- to oval-shaped, and able to grow at pH 6.5-9.0 (optimum, pH 7.0-8.0), at 10-37  °C (optimum, 28 °C) and in the presence of 1-5% (w/v; optimum, 2.5%) NaCl. Ubiquinone-10 was detected as dominant. The main fatty acids (> 5%) of the strain WL0113 T were C 16:0 , iso-C 17:0 3OH, C 20:4 ω6,9,12,15c (arachidonic acid), and summed feature 8 (C 18:1 ω7c and/or C 18:1 ω6c). The major polar lipids include phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine, glycophospholipid, unknown aminolipid, unknown phospholipid, and two unknown polar lipids. The ANI and dDDH values between strain WL0113 T and Roseobacter cerasinus were 80.4% and 23.0%, respectively. The genomic DNA G + C content of strain WL0113 T was 63.1%. Based on these data, it is proposed that strain WL0113 T represent novel species of the genus Roseobacter, for which the name Roseobacter sinensis sp. nov. is proposed. The type strain is WL0113 T (= GDMCC 1.3082 T  = JCM 35567 T )., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

An aerobic, Gram-stain negative bacterium was isolated from sediment samples of Barkol salt lake in Hami City, Xinjiang Uygur Autonomous Region, China, with the number EGI_FJ10229 T . The strain is ellipse-shaped, oxidase-negative, catalase-positive, and has white, round, smooth, opaque colonies on marine 2216 E agar plate. Growth occurs at 4.0-37.0 ℃ (optimal:30.0 ℃), pH 7.0-9.0 (optimal: pH 8.0) and NaCl concentration of 0-8.0% (optimal: 3.0%). Phylogenetic analysis based on 16S rRNA gene and genome sequences indicated that the isolated strain should be assigned to the genus Aquibaculum and was most closely related to Aquibaculum arenosum CAU 1616  T . Average nucleotide identity (ANI) and Average amino-acid identity (AAI) values between the type species of the genus Aquibaculum and other related type species were lower than the threshold values recommended for bacterial species. The genomic DNA G + C content of EGI_FJ10229 T was 65.41%. The major polar lipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylcholine, phosphatidylethanolamine and unidentified phospholipid. The major fatty acids (> 5%) were C 19:0 cyclo ω8c (42.0%) and C 18:1 ω7c (33.78%). The respiratory quinone identified was Q-10. Differential phenotypic and genotypic characteristics of this strain and species of genus Aquibaculum showed that the strain should be classified as representing a new species belonging to this genus, for which the name Aquibaculum sediminis sp. nov. is proposed. The type strain of the proposed novel species is EGI_FJ10229 T (= KCTC 8570  T  = GDMCC 1.4598  T )., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

A Gram-stain-negative, aerobic, motile and rod-shaped bacterium, the color of the bacterial colony ranges from light yellow to yellow, designated YC-2023-2T, was isolated from sediment sample of Yuncheng salt lake. Growth occurred at 15-45℃ (optimum 37℃), pH 6.0-9.0 (optimum pH 7.0-8.0) and with 0-8.0% NaCl (w/v, optimum 2.0%). The phylogenetic analysis based on 16S rRNA gene sequences showed that strain YC-2023-2T belonged to the family Kordiimonadaceae. The closely related members were Gimibacter soli 6D33T (92.38%), Kordiimonas lipolytica M41T (91.88%), Eilatimonas milleporae DSM 25217T (91.88%) and Kordiimonas gwangyangensis JCM 12864T (91.84%). The genome of strain YC-2023-2T was 2957513 bp, and the genomic DNA G+C content was 63.91%. The main respiratory quinone was Q-10 and the major fatty acids (>10%) were iso-C15:0, C16:0, C19:0 cyclo ω8c, Summed Feature 8 (C18:1 ω6c or C18:1 ω7c) and Summed Feature 9 (iso-C17:1 ω9c or C16:0 10-methyl). The major polar lipids consisted of phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, unidentified glycolipid, unidentified lipid, and two unidentified aminolipids. Based on the phylogenetic, phenotypic and chemotaxonomic characteristics, strain YC-2023-2T is proposed to represent a novel species of a novel genus named Yunchengibacter salinarum gen. nov., sp. nov., within the family Kordiimonadaceae. The type strain is YC-2023-2T (= GDMCC 1.4502T = KCTC 8546T)., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

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.)

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.)

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.)

A Gram-stain-negative, motile (by single polar flagellum) and rod-shaped bacterium, designated W1-6 T , was isolated from a sediment of drainage ditch in winery in Guiyang, south-western China. Strain W1-6 T showed the highest 16S rRNA gene sequence similarities with the type strain of Acidovorax wautersii (98.1%) and Simplicispira lacusdiani (97.9%). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain W1-6 T was placed adjacent to the members of the genus Simplicispira and formed a separat subclade. Cells showed oxidase and catalase negative reactions. The only respiratory quinone detected was ubiquinone-8 (Q-8). Summed feature 3 (C 16:1 ω7c and/or C 16:1 ω6c), C 16:0 and summed feature 8 (C 18:1 ω7c and/or C 18:1 ω6c) were predominant cellular fatty acids (> 10%) of strain W1-6 T . Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and five unidentified phospholipids were found in the polar lipid extraction. The genomic DNA G + C content was 65.6%. Strain W1-6 T shared the highest digital DNA-DNA hybridization [dDDH, (27.6%)] and average nucleotide identity [ANI (84.3%)] values with the type strain of S. lacusdiani. The dDDH and ANI values were below the cutoff level (dDDH 70%; ANI 95-96%) for species delineation. The polyphasic characteristics indicated that the strain W1-6 T represents a novel species of the genus Simplicispira, for which the name Simplicispira sedimenti sp. nov. is proposed. The type strain is W1-6 T (= CGMCC 1.16274 T  = NBRC 115624 T )., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

A Gram-positive, facultatively anaerobic, oval beaded-shape, oxidase-negative, and non-motile bacterium designated DM20194951 T was isolated from a spoiled eye mask obtained from Guangdong, China. Based on the 16S rRNA gene sequence, phylogenetic analysis indicated that strain DM20194951 T showed the highest sequence similarity (95.8%) to Fundicoccus ignavus WS4937 T . Meanwhile, strain DM20194951 T could be distinguished from the type strains in the genus Fundicoccus by distinct phenotypic and genotypic traits. Strain DM20194951 T grew variably with 1-2% (w/v) NaCl and tolerated pH 6.0-10.0. Growth was observed from 28 to 37 °C. The diagnostic diamino acids in the cell-wall peptidoglycan consisted of aspartic and glutamic acids as well as alanine. The predominant fatty acids were C 18:1 ω9c, C 16:0 , and C 16:1 ω9c. In the polar lipid profile, two glycolipids, three phospholipids, one phosphatidylglycerol, and one diphosphatidylglycerol were found. No respiratory quinones were detected. The DM20194951 T genome is 3.2 Mb in size and contains a G + C content of 38.1%. A gene cluster for lactococcin 972 family bacteriocin production was found in the DM20194951 T genome. Based on morphological, genotypic, and phylogenetic data, strain DM20194951 T should be considered to represent a novel species in the genus Fundicoccus, for which the name Fundicoccus culcitae sp. nov. is proposed with the type strain DM20194951 T (= KCTC 43472 T  = GDMCC 1.3614 T )., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

A Gram-staining negative, aerobic, motile, and short rods strain, designated SYSU M60028 T , was isolated from a Pearl River sediment sample in Guangzhou, Guangdong, China. The isolate could be able to grow at pH 6.0-8.0 (optimum, pH 7.0), 25-37 °C (optimum, 28 °C) and in the presence of 0-2% (w/v) NaCl (optimum, 0% NaCl). The cellular polar lipids of this strain were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, one unidentified aminolipid and three unidentified lipids. The respiratory quinone of SYSU M60028 T was found to be Q-10. The major fatty acids (> 5% of total) were summed feature 8, C 16:0 , and C 18:1 ω7c 11-methy1. The genomic DNA G + C content was 69.9%. Phylogenetic analyses based on 16S rRNA gene sequences and core genes indicated that strain SYSU M60028 T belonged to the genus Alsobacter and had the highest sequences similarities to Alsobacter metallidurans SK200a-9 T (96.87%) and Alsobacter soli SH9 T (96.87%). Based on the phenotypic, genotypic, and phylogenetic data, strain SYSU M0028 T should be considered to represent a novel species of the genus Alsobacter, for which the name Alsobacter ponti sp. nov. is proposed. The type strain is SYSU M60028 T (= CGMCC 1.19341 T  = KCTC 92046 T )., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

A novel actinomycete, designated strain q2 T , was isolated from the saline-alkaline soil, collected from Daqing, Heilongjiang province, China. The results of phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain q2 T belongs to the genus Isoptericola, and showed the highest sequence similarity to Isoptericola halotolerans KCTC 19046 T (98.48%) and Isoptericola chiayiensis KCTC 19740 T (98.13%), respectively. The average nucleotide identity values between strain q2 T and other members of the genus Isoptericola were lower than 95% recommended for distinguishing novel prokaryotic species. Cells of strain q2 T were Gram-staining-positive, aerobic, non-motile, rod-shaped and non-spore-forming. Colonies of strain q2 T were golden-yellow pigmented, tidy edged and smooth surfaced. Growth occurred at 15-37 °C (optimum, 29 °C), pH 7.0-10.0 (optimum, pH 8.0). The predominant respiratory quinones were MK-9(H 4 ) and MK-9(H 2 ). The main detected polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, and phosphatidylinositol mannoside. The peptidoglycan compositions were L-alanine, D-aspartic, L-glutamic acid and L-lysine (type A4α). The major cellular fatty acids (> 10%) were anteiso-C 15:0 , iso-C 15:0 , and anteiso-C 17:0 . The G+C content of the genomic DNA was determined to be 69.7%. Based on the phenotypic, physiological, genotypic, and phylogenetic data, strain q2 T represents a novel species of the genus Isoptericola, for which the name Isoptericola croceus sp. nov. is proposed. The type strain is q2 T (= GDMCC 1.2923 T  = KCTC 49759 T )., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Extremophiles possess unique cellular and molecular mechanisms to assist, tolerate, and sustain their lives in extreme habitats. These habitats are dominated by one or more extreme physical or chemical parameters that shape existing microbial communities and their cellular and genomic features. The diversity of extremophiles reflects a long list of adaptations over millions of years. Growing research on extremophiles has considerably uncovered and increased our understanding of life and its limits on our planet. Many extremophiles have been greatly explored for their application in various industrial processes. In this review, we focused on the characteristics that microorganisms have acquired to optimally thrive in extreme environments. We have discussed cellular and molecular mechanisms involved in stability at respective extreme conditions like thermophiles, psychrophiles, acidophiles, barophiles, etc., which highlight evolutionary aspects and the significance of extremophiles for the benefit of mankind., Competing Interests: Conflict of interestThe authors declare that they had no conflict of interest., (© King Abdulaziz City for Science and Technology 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)

A Gram-staining-negative, aerobic and pear-shaped bacterial strain, designated WL0036 T , was isolated from coastal sediment sample collected in Nantong city, Jiangsu province of China (120° 51' 13″ E, 32° 6' 26″ N) in October 2020. Strain WL0036 T was found to grow at 20-37 °C (optimum, 28 °C) with 0-9.0% NaCl (optimum, 2.5-4.0%) and displayed alkaliphilic growth with the pH range of pH 6.0-10.0 (optimum, pH 7.0-8.0). The polar lipids profile of strain WL0036 T included phosphatidylcholine, phosphatidylethanolamine, glycolipid and an unidentified lipid. The major isoprenoid quinone was determined to be Q-11 and the major fatty acids were C 16:0 , 11-methyl-C 18:1 ω7c, and summed features 8 (C 18:1 ω6c and/or C 18:1 ω7c). The G + C content of genomic DNA was 61.8%. Phylogenetic trees constructed based on 16S rRNA gene sequence and bac120 gene set (a collection of 120 single-copy protein sequences prevalent in bacteria) indicted that strain WL0036 T clustered with strains Hyphomonas neptunium ATCC 15444 T and H. polymorpha PS728 T . The average nucleotide identities between strain WL0036 T and strains H. neptunium ATCC 15444 T and H. polymorpha PS728 T were 80.7% and 81.2%, respectively. Strain WL0036 T showed 22.8% and 23.2% of digital DNA-DNA hybridization identities with H. neptunium ATCC 15444 T and H. polymorpha PS728 T , respectively. As inferred from the phenotypic and genotypic characteristics and the phylogenetic trees, strain WL0036 T ought to be recognized as a novel species in genus Hyphomonas, for which the name Hyphomonas sediminis sp. nov. is proposed. The type strain is WL0036 T (= MCCC 1K05843 T  = JCM 34658 T  = GDMCC 1.2413 T )., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

A few members of the bacterial genus Thermus have been shown to be incomplete denitrifiers, terminating with nitrite (NO 2 - ) or nitrous oxide (N 2 O). However, the denitrification abilities of the genus as a whole remain poorly characterized. Here, we describe diverse denitrification phenotypes and genotypes of a collection of 24 strains representing ten species, all isolated from a variety of geothermal systems in China. Confirmed terminal products of nitrate reduction were nitrite or N 2 O, while nitric oxide (NO) was inferred as the terminal product in some strains. Most strains produced N 2 O; complete denitrification was not observed. Denitrification phenotypes were largely consistent with the presence of denitrification genes, and strains of the same species often had the same denitrification phenotypes and largely syntenous denitrification gene clusters. Genes for nirS and nirK coexisted in three Thermus brockianus and three Thermus oshimai genomes, which is a unique hallmark of some denitrifying Thermus strains and may be ecologically important. These results show that incomplete denitrification phenotypes are prominent, but variable, within and between Thermus species. The incomplete denitrification phenotypes described here suggest Thermus species may play important roles in consortial denitrification in high-temperature terrestrial biotopes where sufficient supply of oxidized inorganic nitrogen exists., (© 2022. The Author(s).)

A thermophilic bacterium, designated strain SYSU G04325 T , was isolated from a hot spring sediment in Yunnan, China. Polyphasic taxonomic analyses and whole-genome sequencing were used to determine the taxonomic position of the strain. Phylogenetic analysis using 16S rRNA gene sequences indicated that strain SYSU G04325 T shows high sequence similarity to Thermoflexibacter ruber NBRC 16677 T (86.2%). The strain can be differentiated from other species of the family Thermoflexibacteraceae by its distinct phenotypic and genotypic characteristics. Cells of the strain SYSU G04325 T were observed to be aerobic, Gram-stain negative and filamentous. Growth was found to occur optimally at 45 ºC and pH 7.0. In addition, the respiratory quinone was identified as menaquinone-7, while the major fatty acids (> 10%) were identified as iso-C 15:0 , iso-C 17:0 and Summed Feature 9 (iso-C 17:1 ω9c). The polar lipids detected included phosphatidylethanolamine, three unidentified phospholipids, one unidentified glycolipid, five unidentified aminolipids and four unidentified polar lipids. The G + C content of the genomic DNA was determined to be 47.6% based on the draft genome sequence. On the basis of phenotypic, genotypic and phylogenetic data, strain SYSU G04325 T is concluded to represent a novel species of a novel genus in the family Thermoflexibacteraceae, for which the name Rhodoflexus caldus gen. nov., sp. nov. is proposed. The type strain of Rhodoflexus caldus is SYSU G04325 T (= MCCC 1K06127 T  = KCTC 82848 T )., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

An alkali and salt-tolerating strain FJAT-44876 T was isolated from the bauxite residue sample. The 16S rRNA gene sequence and phylogenetic analysis suggest that strain FJAT-44876 T was a member of the genus Evansella. It grew at 15-45 ℃ (optimum 20-25 ℃) and pH 6.5-11.0 (optimum pH 8.0-9.0) with 0-20% (w/v) NaCl (optimum 6-8%). The major fatty acids were anteiso-C 15:0 , iso-C 15:0 , anteiso-C 17:0 , iso-C 17:0 , and C 16:0 . The cell wall peptidoglycan contained meso-diaminopimelic acid and MK-7 as the menaquinone. The major polar lipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, and phosphatidylglycerol. The genomic DNA G+C content was 38.2%. The average nucleotide identity values between strain FJAT-44876 T and closely related members were below the cutoff level for species delineation. Thus, based on the above results, strain FJAT-44876 T represents a novel species of the genus Evansella, for which the name Evansella halocellulosilytica sp. nov., is proposed. The type strain is FJAT-44876 T (=CCTCC AB 2016264 T  = DSM 104633 T )., (© 2022. The Author(s), under exclusive licence to Springer Japan KK, part of Springer Nature.)

Phylogenomic analyses were performed on the nine species of the genus Meiothermus and four species of the genus Calidithermus. Phylogenetic analysis, low values of genomic relatedness indices and functional diversity analysis indicated that Meiothermus silvanus should not be classified within the clades for Meiothermus and Calidithermus but instead be reclassified as a new genus, for which we propose the name Allomeiothermus gen. nov., with Allomeiothermus silvanus comb. nov. as type species. In addition, the species Meiothermus cateniformans Zhang et al. (Int J Syst Evol Microbial 60:840-844, 2010) should also be reclassified as a later heterotypic synonym of Meiothermus taiwanensis Chen et al. (Int J Syst Evol Microbiol 52:1647-1654, 2002) emend. Raposo et al. (2019). This reclassification is based on the high genomic relatedness indices (98.8% ANI; 90.2% dDDH; 99% AAI) that are above the threshold values necessary for defining a new species, as well as on the observation of overlapping functions on Principal Coordinate Analysis plot generated from Clusters of Orthologous Genes., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Misplaced or excessive hypochlorous acid in lysosomes has a close association with lots of diseases, so monitoring hypochlorous acid in lysosomes is particularly necessary. In the present work, a novel lysosome-targetable fluorescent probe (Lyso-R-HClO) for hypochlorous acid based on a HClO-mediated cyclization reaction was developed. In the fluorescent probe, the morpholine unit and the site of a HClO-mediated cyclization reaction were, respectively, used as the lysosome-targetable group and the response group. The probe has high selectivity and high sensitivity to hypochlorous acid, with a linear range from 5.0 × 10 -8 to 3.0 × 10 -6  M and a detection limit of 15 nM; it was successfully used to image endogenous and exogenous lysosomal HClO. Finally, Lyso-R-HClO was further applied to image lysosomal HClO produced in bacteria-infected macrophage with satisfactory results, which indicate that it is an useful tool for studies of lysosomal HClO and the role of lysosome., (© 2022. The Author(s), under exclusive licence to The Japan Society for Analytical Chemistry.)

Two novel species of the genus Deinococcus, designated SYSU M49105 T and SYSU M42101 T , were isolated from freshwater samples of the Pearl River estuary in Guangdong, China. Phylogenetic analysis using 16S rRNA gene sequence indicated that strains SYSU M49105 T and SYSU M42101 T showed the highest sequence similarities to Deinococcus aetherius JCM 11751  T (93.6%) and Deinococcus multiflagellatus NBRC 112888  T (97.3%), respectively. Cells of both strains were Gram-staining positive, aerobic, coccus-shaped, oxidase-negative and non-motile. The cell wall contained meso-diaminopimelic acid as their diagnostic diamino acid. MK-8 was the predominant respiratory quinone for both strains. The polar lipid profile of SYSU M49105 T contained two unidentified phosphoglycolipids, nine unidentified glycolipids, and five unidentified polar lipids. SYSU M42101 T had one unidentified phosphoglycolipid, nine unidentified glycolipids, one unidentified aminophospholipid and four unidentified polar lipids. The major fatty acids of strains SYSU M49105 T and SYSU M42101 T were summed feature 3 (C 16:1 ω7c and/ or C 16:1 ω6c) and C 16:0. The G + C contents of the novel isolates based on genomic DNAs were 69.6% and 67.4%, respectively. On the basis of phenotypic, genotypic and phylogenetic data, strains SYSU M49105 T and SYSU M42101 T should be considered to represent two novel species in the genus Deinococcus, for which the names Deinococcus aestuarii sp. nov. and Deinococcus aquaedulcis sp. nov. were proposed with the type strains SYSU M49105 T (= KCTC 43258  T  = CGMCC 1.18609  T ) and SYSU M42101 T (= KCTC 43257  T  = CGMCC 1.18614  T ), respectively., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Three Gram-staining negative, facultatively anaerobic, rod-shaped and motile strains, FJAT-51800 T , FJAT-52962 T and FJAT-54481 T were isolated from the sediment samples of Zhangjiang Estuary Mangrove National Nature Reserve in Fujian Province, China. The 16S rRNA gene sequencing results indicated they could be novel members of the genus Shewanella. The optimum temperature for growth was 30 °C. The respiratory quinones of the strains were ubiquinone Q-7 or Q-8, and menaquinone MK-7. Polar lipids of the strains FJAT-52962 T and FJAT-51800 T were phosphatidyl glycerol, phosphatidyl ethanolamine, and unidentified aminophospholipids while strain FJAT-54481 consist of phosphatidylglycerol, phosphatidylethanolamine, unidentified aminophospholipids, two unidentified aminolipids and four unidentified lipids. The major fatty acid of the three strains was iso-C 15:0 . The genomic DNA G + C contents of strains FJAT-51800 T , FJAT-52962 T and FJAT-54481 T were 48.2, 55.3 and 48.1%, respectively. The average nucleotide identity and digital DNA-DNA hybridization values between strains FJAT-51800 T , FJAT-52962 T and FJAT-54481 T and other closely related Shewanella members were below the cut-off level (95-96%) for species identification. Genome analysis showed that these strains encode genes for osmo-regulation. Based on the results of phenotypic, chemotaxonomic and genome analyses, strains FJAT-51800 T , FJAT-52962 T and FJAT-54481 T represent three novel species of the genus Shewanella, for which the names Shewanella avicenniae sp. nov., Shewanella sedimentimangrovi sp. nov., and Shewanella yunxiaonensis sp. nov., are proposed. The type strains are FJAT-51800 T (= GDMCC 1.2204 T  = KCTC 82448 T ), FJAT-52962 T (= MCCC 1K05496 T  = KCTC 82445 T ) and FJAT-54481 T (= GDMCC 1.2348 T  = KCTC 82646 T )., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The haloalkalitolerant bacterium Egicoccus halophilus EGI 80432 T exhibits high adaptability to saline-alkaline environment. The salinity adaptation mechanism of E. halophilus EGI 80432 T was fully understood based on transcriptome analyses and physiological responses; however, the alkaline response mechanism has not yet been investigated. Here, we investigated the alkaline response mechanism of E. halophilus EGI 80432 T by a transcriptomic comparison. In this study, the genes involved in the glycolysis, TCA cycle, starch, and trehalose metabolism for energy production and storage, were up-regulated under highly alkaline condition. Furthermore, genes responsible for the production of acidic and neutral metabolites, i.e., acetate, pyruvate, formate, glutamate, threonine, and ectoine, showed increased expression under highly alkaline condition, compared with the control pH condition. In contrast, the opposite results were observed in proton capture or retention gene expression profiles, i.e., cation/proton antiporters and ATP synthases. The above results revealed that E. halophilus EGI 80432 T likely tended to adopt an "acidic metabolites production" strategy in response to a highly alkaline condition. These findings would pave the way for further studies in the saline-alkaline adaptation mechanisms of E. halophilus EGI 80432 T , and hopefully provide a new insight into the foundational theory and application in ecological restoration with saline-alkaline strains., (© 2021. The Author(s), under exclusive licence to Springer Japan KK, part of Springer Nature.)

Two extremely halophilic archaea, isolates SYSU A00711 T and SYSU A00630, were isolated from a sediment soil sample collected from the Aiding lake, China. Cells of these isolates were cocci, non-motile and stained Gram-negative. They grew optimally at 37 °C, with 20-22% NaCl (w/v) and at pH 7.5-8.0. Cells lysed in distilled water. Major polar lipids were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, mannosyl glucosyl diether, sulfated mannosyl glucosyl diether, and two unidentified glycolipids. Pairwise sequence comparison revealed that isolates SYSU A00711 T and SYSU A00630 were closely related to Halegenticoccus soli SYSU A9-0 T (94.1 and 94.0% 16S rRNA gene sequence similarities; 94.0 and 94.2% rpoB' gene similarities, respectively). The overall genomic relatedness indices values between the two isolates and Halegenticocus soli SYSU A9-0  T were: AAI, both 79.6%; ANI, 84.6 and 84.5%; dDDH, 32.5 and 26.3%, respectively. Phylogenetic trees based on the 16S rRNA gene, rpoB' gene, and genome sequences demonstrated a robust clade of these two isolates with Halegenticoccus soli SYSU A9-0 T . The DNA G + C contents of these two isolates are both 64.7% (genome method). Based on the differences in phenotypic, chemotaxonomic, and phylogenetic properties, isolates SYSU A00711 T and SYSU A00630 are characterized to represent a novel species in the genus Halegenticoccus, for which the name Halegenticoccus tardaugens sp. nov. is proposed. The type strain of the species Halegenticoccus tardaugens is SYSU A00711 T (= KCTC 4245 T  = CGMCC 1.15768 T )., (© 2021. The Author(s), under exclusive licence to Springer Japan KK, part of Springer Nature.)

Six aerobic Gram-negative bacteria were isolated from seawater in Guangdong Province, P.R. China. Cells were observed to be Gram-negative, aerobic, non-motile and non-spore forming. Growth of the designated type strain 19X3-30 T occurred at a temperature range of 14-37 °C (optimum, 28 °C), a pH range of 6.0-8.0 (optimum, pH 7) and up to 7.5% NaCl (optimum, 1.5%; w/v), and was enhanced by CO 2 and L-cysteine supplementation. The major polar lipids identified in strain 19X3-30 T were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The principal cellular fatty acids profile showed the presence of anteiso-C 15:0 , anteiso-C 17:0 and C 18:0 (> 8% of total fatty acids), and the respiratory quinone was ubiquinone 8 (UQ-8). According to the analysis of 16S rRNA gene sequences, these strains represented a novel species within the family Fastidiosibacteraceae, sharing maximum similarities with Cysteiniphilum litorale DSM 101832 T (96.6%) and Cysteiniphilum halobium DSM 103992 T (95.3%). Phylogenetic dendrograms based on 16S rRNA gene and protein marker genes from the genomic sequences both indicated that the strains formed a monophyletic lineage closely linked to the genus Cysteiniphilum, which was also supported by the UPGMA dendrogram based on the MALDI-TOF MS profile. The genomic DNA G + C contents of six strains ranged from 38.0% to 38.1%. Based on different taxonomic genomic metrics, phylogeny and phenotypic features, we propose that the strains warrant the assignment to a novel species, for which the name Cysteiniphilum marinum sp. nov. is proposed. The type strain is 19X3-30 T (= KCTC 82154 T  = CGMCC 1.18585 T ).

Two bacterial strains SYSU G02173 T and SYSU G03142 were isolated from hot springs in Tibet, China. Based on the results of nearly full-length 16S rRNA gene sequences and phylogenetic analyses, strains SYSU G02173 T and SYSU G03142 were assigned to the family Sphingosinicellaceae, and were closest to Sandaracinobacter sibiricus RB16-17  T (96.04% and 96.12% similarity, respectively). Cells of the both new strains were observed to be motile rod-shape, Gram-staining negative. Growth occurred at pH 6-8 (optimal: pH 7.0) and 37-55 °C (optimal: 45 °C) with 0-1.0% (w/v) NaCl in T4 broth. The cells were found to be positive for oxidase and catalase activities. The major respiratory ubiquinone was Q-8. The major fatty acids were identified as summed feature 8 (C 18:1 ω7c and/or C 18:1 ω6c), C 16:0 , C 14:0 2-OH. The major polar lipids were found to consist of sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified phospholipid, one unidentified glycolipid, three unidentified aminolipids and two unidentified polar lipids. The DNA G + C contents of strains SYSU G02173 T and SYSU G03142 were 71.8%. The average nucleotide identity (ANI) value between strain SYSU G02173 T and SYSU G03142 was 99.98%. The amino acid identity (AAI) values between them and their closely related species were below 66.14%. The isolates are characterized by aerobic growth, a yellow endocellular pigment and a higher optimum growth temperature. The results showed that strains SYSU G02173 T and SYSU G03142 represent a novel species of a novel genus in the family Sphingomonadaceae, and thus the name Thermaurantiacus tibetensis (type strain SYSU G02173 T  = KCTC 72052  T  = CGMCC 1.16680  T ) is proposed.

A Gram-staining-negative, non-motile, aerobic bacterium, designated 1-3 T , was isolated from oil reservoir water collected from Liaohe oilfield, north-east of China. Growth was observed at 15-40 °C (optimum 37 °C) and pH 6-10 (optimum 7). The strain can grow under nitrogen-limiting condition. Phylogenetic analysis based on 16S rRNA gene sequences showed that the novel isolate was most closely related to Siccirubricoccus deserti SYSU D8009 T (96.7%), followed by Paracraurococcus ruber NS89 T (95.7%) and Belnapia rosea CPCC 100156 T (94.9%). Genome sequencing revealed a genome size of 6.43 Mbp and a G+C content of 71.3 mol%. The average nucleotide identity values and digital DNA-DNA hybridization between 1-3 T and the reference strains were all below the cut-off level (95-96% and 70%, respectively) for species delineation. The strain possessed the cytochrome P450 enzyme, which has the potential to degrade oil. The respiratory quinone was Q-10 and the major fatty acids were summed feature 8 (C 18:1 ω7c/C 18:1 ω6c, 38.8%), C 16:0 (25.6%) and C 19:0 cyclo ω8c (22.5%). The polar lipids of strain 1-3 T comprised diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and three unidentified aminolipids. Based on the genotypic and phenotypic characteristics, strain 1-3 T represents a novel species of genus Siccirubricoccus, for which the name Siccirubricoccus phaeus sp. nov. is proposed. The type strain of Siccirubricoccus phaeus is 1-3 T (= CGMCC 1.16799 T  = LMG 31398 T ).

Cordyceps militaris is a traditional Chinese medicinal food that is challenging to quality maintaining while mass cultivation. Many studies have found that abundant microbes inhabit Ophiocordyceps sinensis and perform important functions for their host. In this study, our objective was to reveal the microbial communities that inhabit C. militaris and analyze their potential functions. High-throughput sequencing of 16S rRNA and ITS genes was used to compare the diversity and composition of the bacterial and fungal communities associated with naturally occurring C. militaris collected from Yunnan Province, southwestern China. The diversity and richness of the microbial communities and the number of function genes of the bacteria were significantly higher in the habitat soil than in the fruiting body. The sclerotia and stromata samples shared the same microbiota and functions. The main bacterial phyla were Proteobacteria, Acidobacteria, Bacteroidetes and Actinobacteria, and Ascomycota was the main fungal phylum. The growth-promoting bacteria Herbaspirillum and the plant probiotic Phyllobacterium, which may enhance C. militaris quality and facilitate its cultivation, were detected in the fruiting body samples. Genes related to metabolism were more abundant in the soil bacteria, while membrane transport genes were more abundant in the endophytic bacteria of C. militaris. Our study is the first to reveal the unexpectedly high diversity of the microbial communities and the bacterial functions inhabiting the natural C. militaris using high-throughput sequencing, and our results provide insights into mining the functions of microorganisms in the development and quality of C. militaris.

A Gram-staining-negative bacterium, strain HHU 13199 T , was isolated from a marine sediment sample collected from South China Sea (119°19.896'E, 19°41.569'N) at a depth of 2918 m. The 16S rRNA gene sequence analysis indicated that strain HHU 13199 T represents a member of the genus Salinimonas with the highest sequence similarity (99.8%) to the type strain S. iocasae KX18D6 T . However, the average nucleotide identity values and digital DNA-DNA hybridization between strain HHU 13199 T and closely related members of the genus Salinimonas were all below the cut-off level (95-96 % and 70%, respectively) for species delineation. This strain grew with sea salt of 0.5-18% (w/v) (optimum, 2-5%), but no growth observed when using NaCl instead. The major fatty acids are C 16:0 , summed feature 3 (C 16:1 ω7c and/or C 16:1 ω6c), and summed feature 8 (C 18:1 ω7c and/or C 18:1 ω6c). The predominant isoprenoid quinone is ubiquinone-8. The polar lipids mainly consist of phosphatidylethanolamine, and phosphatidylglycerol. Genomic characterization revealed that strain HHU 13199 T harbors a distinct type I-F CRISPR-Cas system and plenty of genes associated with heavy metal resistance, including a transposon (Tn6333) conferring mercury resistance. In addition, a phylogenetic tree based on the bac120 core genes suggested that the genus Salinimonas should be a subclade within Alteromonas. On the basis of the phenotypic, phylogenetic and chemotaxonomic characterizations, strain HHU 13199 T represents a novel species of the genus Salinimonas, for which the name Salinimonas profundi sp. nov. is proposed. The type strain is HHU 13199 T (= KCTC 72837 T = MCCC 1K04127 T ).

A Gram-stain-negative, aerobic, motile strain, HHU CXW T , was isolated from hair of a healthy 21-year-old female student of Hohai University, Nanjing, China. The 16S rRNA gene sequence analysis indicated that HHU CXW T represents a member of the genus Sphingomonas with the highest sequence similarity (97.6%) to the type strain S. aquatilis JSS7 T . HHU CXW T grew at 4-35 °C and pH 6-8, with optimum growth at 28 °C and pH 7. Tolerance to NaCl was up to 2% (w/v) with optimum growth in 0.5-1.0% NaCl. The major fatty acids were C 16:0 , C 17:1 ω6c, C 18:1 ω7c11-methyl, summed feature 3 (C 16:1 ω7c and/or C 16:1 ω6c), and summed feature 8 (C 18:1 ω7c and/or C 18:1 ω6c). The predominant isoprenoid quinone was ubiquinone-10. The polar lipids were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), sphingoglycolipid (SGL), phosphatidylinositol mannosides (PIM), and an unidentified glycolipid (GL). The DNA G + C content was 67.1%. The average nucleotide identity (ANI) values and digital DNA-DNA hybridization (dDDH) between HHU CXW T and closely related members of the genus Sphingomonas were all below the cut-off level (95-96% and 70%, respectively) for species delineation. On the basis of the phenotypic, phylogenetic and chemotaxonomic characterizations, HHU CXW T represents a novel species of the genus Sphingomonas, for which the name Sphingomonas hominis sp. nov. is proposed. The type strain is HHU CXW T (= KCTC 72946 T  = CGMCC 1.17504 T  = MCCC 1K04223 T ).

A β-glucosidase gene (bsbgl1a) from Bacillus sp. CGMCC 1.16541 was expressed in Escherichia coli BL21 and subsequently characterized. The amino acid sequence shared 83.64% identity with β-glucosidase (WP_066390903.1) from Fictibacillus phosphorivorans. The recombinant β-glucosidase (BsBgl1A) had a molecular weight of 52.2 kDa and could hydrolyze cellobiose, cellotriose, cellotetrose, p-nitrophenyl-β-D-glucopyranoside (pNPG), and p-nitrophenyl-β-D-xylopyranoside (pNPX). Optimal activity for BsBgl1A was recorded at 45 °C with a pH between 5.6 and 7.6, and 100% of its activity was maintained after a 24 h incubation between pH 4 and 9. Kinetic characterization revealed an enzymatic turnover (Kcat) of 616 ± 2 s -1 (with cellobiose) and 3.5 ± 0.1 s -1 (with p-nitrophenyl-β-D-glucopyranoside). Interestingly, the recombinant enzyme showed cupric ion (Cu 2+ ), sodium dodecyl sulfate (SDS) and alcohol tolerance at 10 mM for Cu 2+ and 10% for both SDS and alcohol. Additionally, BsBgl1A had high tolerance for glucose (Ki = 2095 mM), which is an extremely desirable feature for industrial applications. Following the addition of BsBgl1A (0.05 mg/ml) to a commercial cellulase reaction system, glucose yields from sugarcane bagasse increased 100% after 1 day at 45 °C. This work identifies a Cu 2+ , SDS, alcohol, and glucose tolerant GH1 β-glucosidase with potential applications in the hydrolysis of cellulose for the bioenergy industry.

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 novel proteobacterial strain designated SYSU H10001 T was isolated from a soil sample collected from plateau meadow in Hongyuan county, Sichuan province, south-western China. The taxonomic position of the strain was investigated using a polyphasic approach. On the basis of 16S rRNA gene sequence similarities and phylogenetic analysis, strain SYSU H10001 T was most closely related to Lysobacter soli KCTC 22011 T (98.6%, sequence similarity) and Lysobacter panacisoli JCM 19212 T (98.2%). The prediction result of secondary metabolites based on genome shown that the strain SYSU H10001 T contained 3 clusters of bacteriocins, 1 cluster of non-ribosomal peptide synthetase, 1 cluster of type 1 polyketide synthase and 1 cluster of arylpolyene. In addition, the major isoprenoid quinone was Q-8 and the major fatty acids were identified as iso-C 15:0 , iso-C 17:0 and Summed feature 9. The polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and three unidentified phospholipids. The genomic DNA G + C content of strain SYSU H10001 T was 66.5% (genome). On the basis of phenotypic, genotypic and phylogenetic data, strain SYSU H10001 T represents a novel species of the genus Lysobacter, for which the name Lysobacter prati sp. nov. is proposed. The type strain is SYSU H10001 T (= KCTC 72062 T  = CGMCC 1.16662 T ).

The present study was conducted to analyze bacterial diversity profile of Cholistan desert located in Pakistan. The study investigates the influence of physicochemical parameters of soil on distribution of different bacteria at all taxonomic levels and also study the distribution pattern between different desert environments, particularly rhizospheric and bulk desert sands. Species richness showed phyla Proteobacteria and Chloroflexi as the dominant OTUs in all the samples. Besides the two phyla, the rhizospheric soils with root remnants were dominated by Firmicutes, Deinococcus-Thermus, Actinobacteria and Acidobacteri , while phylum Thermotogae was present in significant quantity in rhizosheaths devoid of roots. In non-rhizospheric desert soils, a considerable number of OTUs belonged to phyla Proteobacteria, Chloroflexi, Bacteroidetes and Acidobacteria . An important finding from this study is that a bulk portion of the OTUs were assigned to unclassified taxa, indicating a large repertoire of unexplored taxa in the desert ecology of Pakistan. Distribution of taxonomic groups among various regions of the desert was collaborating well with the physicochemical parameters of the sites. The findings of this study establish the fundamental relationships between desert ecosystem, specific native plant and the total bacterial flora. This is the first study of microbial community analysis of any desert in Pakistan and thus, will serve as a future platform to explore further on desert ecosystem functioning by employing the ever-changing biotechnological tools., Competing Interests: Conflicts of interestThe authors declare no conflict of interest.Ethical statementIt is to state that all the authors agreed to the contents of the manuscript and also agreed that we (Dr. Iftikhar Ahmed from Pakistan and Professor Dr. Wen-Jun Li from China) would act as corresponding authors for the publication. It is also declared that there is no conflict of interest with anyone and we do not have choice for any Editor and /or Reviewer to be included or excluded for reviewing this manuscript., (© King Abdulaziz City for Science and Technology 2020.)

The group Nitriliruptoria, recently classified as a separate class of phylum Actinobacteria, has five members at present, which belong to halophilic or halotolerant Actinobacteria. Here, we sequenced the genomes of Egicoccus halophilus EGI 80432 T and Egibacter rhizosphaerae EGI 80759 T , and performed a comparative genomics approach to analyze the genomic differences and salt adaptation mechanisms in Nitriliruptoria. Phylogenetic analysis suggested that Euzebya tangerina F10 T has a closer phylogenetic relationship to Euzebya rosea DSW09 T , while genomic analysis revealed highest genomic similarity with Nitriliruptor alkaliphilus ANL-iso2 T and E. halophilus EGI 80432 T . Genomic differences of Nitriliruptoria were mainly observed in genome size, gene contents, and the amounts of gene in per functional categories. Furthermore, our analysis also revealed that Nitriliruptoria possess similar synthesis systems of solutes, such as trehalose, glutamine, glutamate, and proline. On the other hand, each member of Nitriliruptoria species possesses specific mechanisms, K + influx and efflux, betaine and ectoine synthesis, and compatible solutes transport to survive in various high-salt environments.

Thermus species are thermophilic heterotrophs, with most capable of using a variety of organic and inorganic electron donors for respiration. Here, a combined cultivation-independent and -dependent approach was used to explore the diversity of Thermus in Great Boiling Spring (GBS) and Little Hot Creek (LHC) in the US Great Basin. A cultivation-independent 16S rRNA gene survey of ten LHC sites showed that Thermus made up 0-3.5% of sequences and were predominately Thermus thermophilus. 189 Thermus isolates from GBS and LHC were affiliated with T. aquaticus (73.0%), T. oshimai (25.4%), T. sediminis (1.1%), and T. thermophilus (0.5%), with T. aquaticus and T. oshimai forming biogeographic clusters. 22 strains were selected for characterization, including chemolithotrophic oxidation of thiosulfate and arsenite, and reduction of ferric iron, polysulfide, and nitrate, revealing phenotypic diversity and broad respiratory capability within each species. PCR demonstrated the wide distribution of aerobic arsenite oxidase genes. A GBS sediment metaproteome contained sulfite oxidase and Fe 3+ ABC transporter permease peptides, suggesting sulfur and iron transformations in situ. This study expands our knowledge of the physiological diversity of Thermus, suggesting widespread chemolithotrophic and anaerobic respiration phenotypes, and providing a foundation for better understanding the ecology of this genus in thermal ecosystems.

A novel actinobacterial strain, designated SYSU K12189 T , was isolated from a soil sample collected from a Karst cave in Xingyi county, Guizhou province, south-western China. The taxonomic position of the strain was investigated using a polyphasic approach. Cells of the strain were observed to be aerobic and Gram-stain positive. On the basis of 16S rRNA gene sequence similarities and phylogenetic analysis, strain SYSU K12189 T is closely related to the type strains of the genus Microlunatus, Microlunatus parietis 12-Be-011 T (98.5% sequence similarity), Microlunatus nigridraconis CPCC 203993 T (98.4%) and Microlunatus cavernae YIM C01117 T (96.6%), and is therefore considered to represent a member of the genus Microlunatus. DNA-DNA hybridization values between strain SYSU K12189 T and related type strains of the genus Microlunatus were < 70%. In addition, LL-diaminopimelic acid was found to be the diagnostic diamino acid in the cell wall peptidoglycan. The major isoprenoid quinone was identified as MK-9(H 4 ), while the major fatty acids (> 10%) were found to be anteiso-C 15:0 , iso-C 15:0 , iso-C 16:0 and iso-C 14:0 . The polar lipids were found to contain diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, three glycolipids and two unidentified lipids. The genomic DNA G+C content of strain SYSU K12189 T was determined to be 69.4 mol%. On the basis of phenotypic, genotypic and phylogenetic data, strain SYSU K12189 T is concluded to represent a novel species of the genus Microlunatus, for which the name Microlunatus speluncae sp. nov. is proposed. The type strain is SYSU K12189 T (= KCTC 39847 T  = DSM 103947 T ).

In the present study, phylogenetic and genome-based comparison was carried out to clarify the taxonomic positions of alkaliphilic Bacillus species, Bacillus plakortidis, Bacillus lehensis, Bacillus oshimensis, Bacillus rhizosphaerae and Bacillus clausii. Phylogenetic trees based on 16S rRNA gene sequences and concatenated protein marker genes were constructed. Average nucleotide identity (ANI) values were calculated to compare genetic relatedness. In phylogenetic trees, B. plakortidis DSM 19153 T , B. lehensis DSM 19099 T , and B. oshimensis DSM 18940 T ; B. rhizosphaerae DSM 21911 T and B. clausii DSM 8716 T clade together. The average nucleotide identity (ANI) values between B. oshimensis DSM 18940 T , B. plakortidis DSM 19153 T and B. lehensis DSM 19099 T ranged from 98.7-98.8%, while the ANI values between B. rhizosphaerae DSM 21911 T and B. clausii DSM 8716 T were 95.2-95.5%. The ANI values were higher than the recognized threshold value for bacterial species delineation. Based on phylogenetic and genome comparison we propose reclassification of B. plakortidis and B. lehensis as a later heterotypic synonym of B. oshimensis; B. rhizosphaerae as a later heterotypic synonym of B. clausii.

A Gram-stain negative, aerobic bacterium, designated strain YIM 78456 T , was isolated from a hot spring sediment, Ngamring county, Tibet, south-west China. The taxonomic position of the isolate was investigated by a polyphasic approach. The novel isolate was found to be aerobic and rod-shaped. Colonies were observed to be pale yellow and circular. The strain was found to grow at pH 7.0-8.0 (optimum, pH 7.0), 45-65 °C (optimum, 55 °C) and in the presence of up to 1.5% NaCl. Comparison of the 16S rRNA gene sequence of strain YIM 78456 T and other members of the genus Thermus showed sequence similarities ranging from 90.3 to 97.3%, with strain YIM 78456 T showing close sequence similarity to Thermus caliditerrae YIM 77925 T (97.3%). The phylogenetic trees based on 16S rRNA gene sequences showed that strain YIM 78456 T forms a distinct clade with T. caliditerrae YIM 77925 T . The predominant menaquinone was identified as MK-8 and the DNA G+C content was determined to be 65.1 mol%. The major cellular fatty acids (> 10%) were identified as iso-C 15:0 , anteiso-C 15:0 and iso-C 17:0 . The polar lipids were found to consist of an aminophospholipid, a phospholipid and glycolipids. On the basis of the morphological and chemotaxonomic characteristics, as well as genotypic data, it is proposed that strain YIM 78456 T represents a novel species of the genus Thermus, for which the name Thermus caldilimi sp. nov. is proposed. The type strain is YIM 78456 T (= KCTC 52948 T  = NBRC 113036 T ).

Two alkaliphilic strains, designated FJAT-45086 T and FJAT-45122 T , were isolated from alkali soli in Nima County, Tibet, China. Both strains were Gram-positive, rod-shaped and shared low 16S rRNA gene sequence similarity with the members of the genus Bacillus. They contained meso-diaminopimelic acid as the cell-wall diamino acid and MK-7 as the menaquinone. The major fatty acids (>5%) of strain FJAT-45086 T were anteiso-C 15:0 , C 16:0 , iso-C 15:0 , C 16:1 ω11c and anteiso-C 17:0, whereas strain FJAT-45122 T consisted of iso-C 15:0 , anteiso-C 15:0 , iso-C 17:1 ω10c, iso-C 17:0 , anteiso-C 17:0 , C 16:0 and C16:1ω11c. The genome G + C content of strains FJAT-45086 T and FJAT-45122 T was 37.8 and 38.2 mol%, respectively. The polar lipids of strain FJAT-45086 T were diphosphatidyl glycerol (DPG), phosphatidyl glycerol (PG), phosphatidyl ethanolamine (PE), and phosphatidyl choline (PC), whereas strain FJAT-45122 T consisted of DPG, PG, phosphatidyl methyl ethanolamine (PME) and an unidentified aminophospholipids (UAPL). The average nucleotide identity values of strains FJAT-45086 T and FJAT-45122 T were below the cut-off level (95-96%) for species delineation. Based on the results, strains FJAT-45086 T and FJAT-45122 T represent two novel species of the genus Bacillus, for which the names Bacillus alkalisoli sp. nov., and Bacillus solitudinis sp. nov., are proposed. The type strain, FJAT-45122 T (=DSM 104631 T  = CCTCC AB 2016254 T ), FJAT-45086 T (=DSM 104056 T  = CCTCC AB 2016232 T ).

A Gram-stain negative, facultatively anaerobic, rod-shaped, non-motile and non-spore forming bacterium, designated ZS-11 T , was isolated from an artificial freshwater lake in Guangzhou city, Guangdong province, China. Growth of strain ZS-11 T was observed at the temperature 18-42 °C (optimum 32-37 °C), pH 6.0-8.0 (optimum 7.0) and 0.5-3.0% (w/v) NaCl (optimum 0.5%, w/v), and also found to be enhanced in the presence of CO 2 . Pairwise comparison of 16S rRNA gene sequences showed that the strain shared high similarities with Serratia entomophila DSM 12358 T (96.1%), Serratia ficaria DSM 4569 T (96.0%), Serratia plymuthica DSM 4540 T (96.0%), Rahnella victoriana FRB 225 T (95.9%) and Rouxiella badensis DSM 100043 T (95.8%). The phylogenomic dendrograms showed that strain ZS-11 T formed a distinct cluster within the clade of the genus Serratia. The major fatty acids (> 20%) present in the cells were C 16:0 , C 16:1 ω7c/C 16:1 ω6c and C 18:1 ω7c/C 18:1 ω6c, which were consistent with those of S. entomophila CCUG 55496 T and Serratia liquefaciens CCUG 9285 T . The DNA G + C content for the genome was 49.3%. Based on these phenotypic and genotypic data, strain ZS-11 T is considered to represent a new species of the genus Serratia, for which the name Serratia microhaemolytica sp. nov. is proposed. The type strain is ZS-11 T (= CCTCC AB 2018040 T  = KCTC 62413 T ).

Two extreme halophilic archaeal strains, SYSUA9-0 T and SYSUA9-1, were isolated from Ebi lake of Xinjiang, China. The colonies were Gram-negative, coccoid, and non-motile. Strains were aerobic and grew at 25-50 °C (optimum at 37 °C), in the presence of 10-35% (w/v) NaCl (optimum at 20-22%), and pH 6.0-8.0 (optimum at 7.0). The 16S rRNA gene sequence result revealed that the two strains were closely related to Haloprofundus marisrubri SB9 T (92.7% similarity). The DNA-DNA hybridization value (97% ± 1%) suggested that SYSUA9-0 T and SYSUA9-1 were similar; however, their sequence similarities with other archaeal members suggested that they were novel candidates. The genomic G + C content of SYSUA9-0 T was 66.9%. The average nucleotide identity value between SYSU A9-0 T and Haloprofundus marisrubri SB9 T was 69.1%, which was far below the cutoff value (95-96%) proposed to define the species boundary. The polar lipids were phosphatidylglycerol (PG), phosphatidylglycerolphosphate methylester (PGP-Me), sulfated mannosyl glucosyl diether, mannosyl glucosyldiether, and four unidentified glycolipids. Phenotypic, chemotaxonomic and comparative genome analysis suggested that SYSU A9-0 T and SYSU A9-1 represent a novel species of a new genus within the family Haloferacaceae, for which the name Halegenticoccus soli gen. nov., sp. nov., is proposed. The type strain is SYAUA9-0 T (= KCTC4241 T  = CGMCC 1.15765 T ).

Strain SYSU M10002 T was isolated from a water sample collected from the coastal region of Pearl River estuary, Guangdong Province, southern China. The taxonomic position of the isolate was investigated by polyphasic taxonomic approaches. The isolate was found to be Gram-negative, non-motile, short rods and aerobic. The strain was able to grow at 14-37 °C, pH 6.0-10.0 and in the presence of up to 0.5% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SYSU M10002 T is a member of the family Sphingomonadaceae, with high sequence similarity to Sphingorhabdus buctiana T5 T (95.1%). Overall genomic related indices between the genome of strain SYSU M10002 T and those of related strains were low to moderate (AAI values < 64.3%; POCP values < 58%), indicating that strain SYSU M10002 T represents a novel lineage within the family Sphinogomonadaceae. Strain SYSU M10002 T contained homospermidine as its polyamine. The major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, sphingoglycolipid, two unidentified phospholipids and an unidentified aminolipid. Ubiquinone Q-9 (44.9%) and Q-10 (43.2%) were the dominant respiratory quinones, along with a minor amount of Q-8 (11.9%). The predominant cellular fatty acids (> 10%) identified were summed feature 3 (C 16:1 ω7c and/or C 16:1 ω6c), summed feature 8 (C 18:1 ω7c) and C 14:0 2-OH. The genomic DNA G+C content was 64.0%. Based on the analyses of the phenotypic, genotypic and phylogenetic characteristics, strain SYSU M10002 T is determined to represent a novel species of a novel genus, for which the name Aestuariisphingobium litorale gen. nov., sp. nov. is proposed. The type strain of the species is SYSU M10002 T (= KCTC 52944 T  = NBRC 112961 T ).

A Gram-negative, aerobic, non-motile and non-spore forming bacterium, designated strain SYSU WZ-2 T , was isolated from an estuarine seawater sample. Growth of strain SYSU WZ-2 T was observed at temperature range of 10-40° C (optimum, 32 °C), pH range of 6-10 (optimum, pH 7-8) and in the presence of up to 5.0% NaCl (w/v). The DNA G+C content of the novel strain was determined to be 30.1% (genome). The major polar lipids were found to be diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, an unidentified aminolipid, two unidentified aminophospholipids and two unidentified phospholipids. The major fatty acids were C 18:0 3-OH (27.5%), C 18:1 ω9c (19.3%), C 16:0 (17.0%) and C 14:0 (12.9%). The respiratory quinone was found to be ubiquinone Q8. Pairwise comparison of the 16S rRNA gene sequence showed that strain SYSU WZ-2 T shares high identities with members of the genera Francisella (94.8-95.9%) and Allofrancisella (93.8-94.2%). The phylogenetic dendrograms based on 16S rRNA gene sequences with the members of the family Francisellaceae showed that the strain SYSU WZ-2 T formed a distinct phylogenetic lineage well separated from the members of the genera Francisella and Allofrancisella. MALDI-TOF mass spectrometric analysis also depicted a different profile for strain SYSU WZ-2 T compared with those of members of the genera Francisella and Allofrancisella. Based on the above results and differences in phenotypic and chemotaxonomic features, strain SYSU WZ-2 T is characterized to represent a new species of a novel genus, for which the name Pseudofrancisella aestuarii gen. nov., sp. nov. is proposed (type strain SYSU WZ-2 T  = KCTC 52557 T  = CGMCC 1.13718 T ).

A motile, rod-shaped and yellow coloured proteobacterium, designated strain SYSU D60017 T , was isolated from a desert soil sample. The bacterium was found to be an obligately aerobic, mesophilic and neutrophilic chemo-heterotroph. Cells were observed to be Gram-stain negative, catalase positive and oxidase positive. The major cellular fatty acids were identified as C 19:0 ω8c cyclo and Summed Feature 8 (C 18:1 ω7c and/or C 18:1 ω6c). The main respiratory quinone identified was ubiquinone-10. The DNA G + C content was determined to be 63.8% based on draft genome sequence data. The polar lipids detected were identified as diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and five unidentified polar lipids. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SYSU D60017 T is a member of the order Rhizobiales, but forms a distinct phylogenetic lineage. The differences in the phenotypic characteristics from members of related genera and its distinct phylogenetic position suggested that the isolate SYSU D60017 T represents a novel species of a novel genus within the order Rhizobiales, for which the name Flaviflagellibacter deserti gen. nov., sp. nov. is proposed. The type strain of the new taxon is SYSU D60017 T (= CGMCC 1.16444 T  = NBRC 112958 T ).

An ovoid to rod-shaped, phototrophic, purple non-sulfur bacterium was isolated from a sediment sample of a hot spring in Tibet, China. Cells of strain YIM 73036 T were Gram-stain negative, non-motile and multiplied by binary fission. Strain YIM 73036 T grew optimally at pH 7.0-7.5 at 37-45 °C. Growth occurred in 0.5-3.5% (w/v) NaCl. Vitamins were not required for growth. The presence of photosynthesis genes pufL and pufM were shown and photosynthesis pigments were formed. Bacteriochlorophyll α, the bacteriopheophytin and carotenoids were present as photosynthetic pigments. Internal cytoplasmic membranes were of the lamellar type. The organism YIM 73036 T was able to grow chemo-organoheterophically, chemo-lithoautotrophically and photo-organoheterotrophically but photo-lithoautotrophic and fermentative growth were not demonstrated. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain YIM 73036 T is closely related to Rhodobacter blasticus ATCC 33485 T (96.65% sequence similarity) and clustered with species of the genus Rhodobacter of the family Rhodobacteraceae. Whole-genome sequence analyses based on the average nucleotide BLAST identity (ANI < 82%) indicated that this isolate belongs to a novel species. The genomic DNA G+C content of organism YIM 73036 T was determined to be 66.0 mol%. Strain YIM 73036 T contained Q-10 as the predominant ubiquinone and C 18:1 ω7c, C 18:1 ω7c 11-methyl and C 18:0 as the major fatty acids. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and unidentified phospholipid. Differential phenotypic and chemotaxonomic properties, together with the phylogenetic distinctiveness, demonstrated that strain YIM 73036 T is distinguishable from other species of the genus Rhodobacter. On the basis of the data presented, strain YIM 73036 T is considered to represent a novel species of the genus Rhodobacter, for which the name Rhodobacter thermarum sp. nov. [type strain YIM 73036 T (= KCTC 52712 T  = CCTCC AB 2016298 T )] is proposed.

A novel actinobacterial strain, designated YIM ART13 T , was isolated from a soil sample collected from a karst cave in Xingyi county, Guizhou province, South western China. The taxonomic position of the strain was investigated using a polyphasic approach. Cells of the strain were found to aerobic and Gram-stain positive. On the basis of 16S rRNA gene sequence analysis, strain YIM ART13 T was found to be closely related to Nocardioides pakistanensis NCCP 1340 T (96.1% sequence similarity) and is therefore considered to represent a member of the genus Nocardioides. In addition, LL-diaminopimelic acid was identified as the diagnostic diamino acid in the cell wall peptidoglycan. The whole cell sugars were found to be mannose, galactose, glucose and ribose. The major isoprenoid quinone was identified as MK-8(H 4 ), while the major fatty acids (> 10%) were identified as iso-C 16:0 , C 18:1 ω9c and C 18:0 10-methyl. The polar lipids were found to contain diphosphatidylglycerol, phosphatidylglycerol phosphatidylinositol and phosphatidylinositol mannoside, an unidentified phospholipid. The genomic DNA G+C content of strain YIM ART13 T was determined from the draft genome sequence to be 70.1 mol%. On the basis of phenotypic, genotypic and phylogenetic data, strain YIM ART13 T represents a novel species of the genus Nocardioides, for which the name Nocardioides speluncae sp. nov. is proposed. The type strain is YIM ART13 T (= KCTC 39593 T  = DSM 100493 T ).