Rhodococcus navarretei sp. nov. and Pseudarthrobacter quantipunctorum sp. nov., two novel species with the ability to biosynthesize fluorescent nanoparticles, isolated from soil samples at Union Glacier, Antarctica.

Two Gram-stain-positive bacterial strains, EXRC-4A-4T and RC-2-3T, were isolated from soil samples collected at Union Glacier, Antarctica. Based on 16S rRNA gene sequence similarity, strain EXRC-4A-4T was identified as belonging to the genus Rhodococcus, and strain RC-2-3T to the genus Pseudarthrobacter. Further genomic analyses, including average nucleotide identity and digital DNA-DNA hybridization, suggested that these strains represent new species. Strain EXRC-4A-4T exhibited growth at temperatures ranging from 4 to 28 °C (optimum between 20 and 28 °C), at pH 5.0-9.0 (optimum, pH 6.0), and in the presence of 0-5.0% NaCl (optimum between 0 and 1% NaCl). Strain RC-2-3T grew at 4-28 °C (optimum growth at 28 °C), pH 6.0-10 (optimum, pH 7.0) and in the presence of 0-5.0% NaCl (optimum, 1% NaCl). The fatty acid profile of EXRC-4A-4T was dominated by C17:1 ω-7, while that of RC-2-3T was dominated by anteiso-C15 : 0. The draft genome sequences revealed a DNA G+C content of 64.6 mol% for EXRC-4A-4T and 65.8 mol% for RC-2-3T. Based on this polyphasic study, EXRC-4A-4T and RC-2-3T represent two novel species within the genera Rhodococcus and Pseudarthrobacter, respectively. We propose the names Rhodococcus navarretei sp. nov. and Pseudarthrobacter quantipunctorum sp. nov. The type strains are Rhodococcus navarretei EXRC-4A-4T and Pseudarthrobacter quantipunctorum RC-2-3T. These strains have been deposited deposited in the CChRGM and BCCM/LMG culture collections with entry numbers RGM 3539/LMG 33621 and RGM 3538/LMG 33620, respectively.

Nocardioides bizhenqiangii sp. nov. and Nocardioides renjunii sp. nov., isolated from soil and faeces of Tibetan antelope (Pantholops hodgsonii) on the Qinghai-Tibet Plateau.

Two novel strain pairs (HM61T/HM23 and S-34T/S-58) were isolated from soil and the faeces of Tibetan antelope (Pantholops hodgsonii) collected at the Qinghai-Tibet Plateau of PR China. All four new isolates were aerobic, non-motile, Gram-stain-positive, catalase-positive, oxidase-negative, and short rod-shaped bacteria. The results of phylogenetic analysis based on the full-length 16S rRNA genes and 283 core genomic genes indicated that the four strains were separated into two independent branches belonging to the genus Nocardioides. Strains HM61T and HM23 were most closely related to Nocardioides pelophilus THG T63T (98.58 and 98.65 % 16S rRNA gene sequence similarity). Strains S-34T and S-58 were most closely related to Nocardioides okcheonensis MMS20-HV4-12T (98.89 and 98.89 % 16S rRNA gene sequence similarity). The G+C contents of the genomic DNA of strains HM61T and S-34T were 70.6 and 72.5 mol%, respectively. Strains HM61T, S-34T and the type strains of closely related species in the analysis had average nucleotide identity values of 75.4-90.5 % as well as digital DNA-DNA hybridization values between 20.1 and 40.8 %, which clearly indicated that the four isolates represent two novel species within the genus Nocardioides. The chemotaxonomic characteristics of strains HM61T and S-34T were consistent with the genus Nocardioides. The major fatty acids of all four strains were iso-C16 : 0, C17 : 1 ω8c or C18 : 1 ω9c. For strains HM61T and S-34T, MK-8(H4) was the predominant respiratory quinone, ll-2,6-diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan, and the polar lipids profiles were composed of diphosphatidylglycerol and phosphatidylglycerol. Based on phylogenetic, phenotypic, and chemotaxonomic data, we propose that strains HM61T and S-34T represent two novel species of the genus Nocardioides, respectively, with the names Nocardioides bizhenqiangii sp. nov. and Nocardioides renjunii sp. nov. The type strains are HM61T (=GDMCC 4.343T=JCM 36399T) and S-34T (=CGMCC 4.7664T=JCM 33792T).

Agromyces seonyuensis sp. nov., isolated from island soil.

A Gram-positive, non-motile, pale yellow coloured actinobacterial strain designated MMS17-SY077T was isolated from island soil, and its taxonomic position was investigated using a polyphasic approach. Strain MMS17-SY077T grew optimally at 30 °C, at pH 7 and in the absence of NaCl on Reasoner's 2A agar. Based on the 16S rRNA gene sequence analysis, the strain was assigned to the genus Agromyces of the family Microbacteriaceae, and the most related species were Agromyces italicus DSM 16388T (98.8 % sequence similarity), Agromyces allii UMS-62T (98.1 %) and Agromyces terreus DS-10T (97.8 %). Strain MMS17-SY077T formed a distinct cluster within the Agromyces clade in the phylogenetic tree. Genome-based comparative analyses confirmed a clear distinction between the strain and neighbouring species, as the highest orthologous average nucleotide identity and digital DNA-DNA hybridization values with other related species were 77.2 and 21.4% respectively, which were far below the cutoffs for species distinction. The diagnostic polar lipids of MMS17-SY077T were diphosphatidylglycerol and phosphatidylglycerol, and unidentified glycolipids and an unidentified aminolipid were also present. The main isoprenoid quinones were menaquinones with 11 and 12 isoprene units (MK-11 and MK-12), and main fatty acids were anteiso-C15 : 0 (34.4 %) and iso-C16 : 0 (33.2 %). The whole-cell hydrolysates contained rhamnose, ribose and galactose as diagnostic sugars, and l-2,4-diaminobutyric acid as the major diamino acid. The DNA G+C content was 72.1 mol %. Based on phenotypic, chemotaxnomic and phylogenetic characterization, strain MMS17-SY077T should be classified as representing a new species of the genus Agromyces, for which the name Agromyces seonyunensis sp. nov. is proposed (type strain MMS17-SY077T=KCTC 49423T=LMG 31762T).

Actinotalea soli sp. nov., isolated from Kubuqi Desert soil.

A Gram-stain positive, facultatively anaerobic, motile rod-shaped strain, BY-33T, was isolated from a soil sample obtained from the Kubuqi Desert, PR China. Phylogenetic analysis based on 16S rRNA gene sequence similarity revealed that strain BY-33T was most closely related to the genus Actinotalea, including Actinotalea ferrariae CF5-4T (98.2 % similarity), 'Actinotalea subterranea' HO-Ch2T (98.0 %), Actinotalea solisilvae THG-T121T (97.6 %), 'Actinotalea bogoriensis' 69B4T (97.5 %), Actinotalea fermentans MT (97.3 %) and 'Actinotalea carbonis' T26T (97.0 %). The strain grew at 0‒37 °C (optimum, 28-30 °C) and pH 6.0-11.0 (optimum, pH 9.0-10.0) and with 0‒8.0 % (w/v) NaCl (optimum, 3.0%) on tryptic soy agar. It had catalase activity, but no oxidase activity. The polar lipids of strain BY-33T contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, and phosphatidylinositol mannosides. The major respiratory quinone of strain BY-33T was MK-10 (H4). Its major fatty acids were anteiso-C15 : 0, anteiso-C15 : 1 A and C16 : 0. The genomic DNA G+C content of strain BY-33T was 73.0 mol% based on total genome calculations. The average nucleotide identity scores between the genomic sequences of strain BY-33T and the other species of the genus Actinotalea were found to be low (ANIm <85.0 %, ANIb <77.0 % and OrthoANIu <78.0 %). Furthermore, the digital DNA-DNA hybridization and average amino acid identity values between strain BY-33T and the closely related species ranged from 20.5 to 21.0% and from 62.2 to 72.2 %, respectively. Based on the results of phylogenetic, phenotypic, genotypic and chemotaxonomic analyses, it is concluded that strain BY-33T represents a novel species within the genus Actinotalea, for which the name Actinotalea soli sp. nov. is proposed. The type strain is BY-33T (=CGMCC 1.17460T=KCTC 49362T).

Agromyces laixinhei sp. nov. isolated from bat feces in China.

Three rod-shaped, Gram-stain-positive, and catalase-positive, phenotypically closely related isolates (HY052T, HY050, and HY045) were obtained from fecal samples collected from bats in Guangxi province and Chongqing city of China. Circular, smooth, light-yellow colonies appeared on brain heart infusion plate after 24-48 h incubation at 28°C. The optimal pH for growth was between 6.0 and 7.5. Based on 16S rRNA, the three isolates were phylogenetically related to Agromyces terreus DS-10T, Agromyces aureus AR33T, Agromyces salentinus 20-5T, Agromyces allii UMS-62T, Agromyces lapidis CD55T, and Agromyces italicus CD1T. Moreover, based on 296 core genes, the phylogenomic tree indicated that the three isolates clustered together, closest to Agromyces cerinus VKM Ac-1340T and Agromyces fucosus VKM Ac-1345T but separated distantly from other Agromyces species. The average nucleotide identity values between strain HY052T and other Agromyces species ranged from 79.3% to 87.9%, lower than the 95-96% threshold. Furthermore, the genome of strain HY052T contains a circular chromosome of 3,437,203 bp with G + C content of 69.0 mol%. Main fatty acids were anteiso-C15:0 and anteiso-C17:0. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, and unidentified glycolipids. Rhamnose, ribose, and glucose were the primary cell wall sugars. The major peptidoglycan amino acids included alanine, glutamic acid, glycine, and 2,4-diaminobutyric acid. An additional remarkable difference from other Agromyces species is that MK-12 was the sole menaquinone in strain HY052T. Based on results from the polyphasic characterizations performed in this study, our isolates are proposed to be members of a novel species in genus Agromyces, named Agromyces laixinhei. The type strain is HY052T (= CGMCC 1.17175T = JCM 33695T).

Puerhibacterium puerhi gen. nov., sp. nov., a novel member of the family Promicromonosporaceae, isolated from Pu-erh tea pile-fermentation.

A Gram-staining positive aerobic bacterium, designated TLY-12T, was isolated from the Pu-erh tea pile-fermentation process in Pu'er city, Yunnan, China. Strain TLY-12T grew at 15-37 °C (optimum, 30 °C), pH 6.0-11.0 (optimum, pH 9.0) and 0-9.0% (w/v) NaCl (optimum, 3.0%). The major cellular fatty acids were anteiso-C15:0, C16:0 and iso-C16:0. The respiratory quinone were menaquinones MK-9 (H2) and MK-9 (H4). The polar lipids were phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), phosphatidylinositol (PI), phosphoglycolipid (PGL), glycolipid (GL) and an unidentified phospholipid (PL). The peptidoglycan contained glutamic acid, aspartic acid, alanine and lysine, with the last named being the diagnostic diamino acid. Whole-cell sugars of the isolate were ribose, galactose and glucose. Phylogenetic analyses of 16S rRNA gene showed that this strain belonged to the family Promicromonosporaceae, and was most closely related to Isoptericola cucumis DSM 101603 T, which gave sequence similarity of 97.9%. Genome sequencing revealed a genome size of 3.91 Mbp and a G + C content of 75.0%. Average nucleotide identity and digital DNA-DNA hybridization values were all below the species threshold of described Promicromonosporaceae species. Genome phylogenetic analysis showed that strain TLY-12T formed a separate evolutionary branch, and was parallel to other related genera of Promicromonosporaceae. Based on the phylogenetic, phenotypic, chemotaxonomic and genome pairwise data, strain TLY-12T is considered to represent a novel species in a new genus in the family Promicromonosporaceae, for which the name Puerhibacterium puerhi gen. nov, sp. nov. is proposed. The type strain is TLY-12T (= CGMCC 1.17157T = KCTC 49467T).

Haloechinothrix aidingensis sp. nov., an actinomycete isolated from salt lake in Xinjiang province, north-west China.

An actinomycete strain, designated YIM 98757T, was isolated from the hypersaline sediment of Aiding Lake in Xinjiang province, north-west China. The strain grew well on most media tested and no diffusible pigment was produced. The substrate mycelium was well developed and fragmented. No spores were formed. The whole-cell hydrolysates contained meso-diaminopimelic acid as the cell-wall diamino acid. Xylose, galactose, ribose were the major whole-cell sugars. The phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannosides and an unknown phospholipid. The predominant menaquinone was MK-8(H4). The major fatty acid was iso-C16:0. The DNA G + C content was 69.1 mol%. Phylogenetic analysis indicated that the isolate belongs to the genus Haloechinothrix. However, it differed from its closest relative, H. alba YIM 98757 T in many phenotypic and chemotaxonomic characteristics. Moreover, the DNA-DNA and ANI relatedness values between the novel isolate and H. alba YIM 93221 T were 53.3% and 92.5%, respectively. Based on comparative analysis of polyphasic taxonomic data, strain YIM 98757 T represents a novel species of the genus Haloechinothrix, for which the name Haloechinothrix aidingensis sp. nov. is proposed. The type strain is YIM 98757T (= CGMCC 4.7627T = CCTCC AA 2020012).

Nonomuraea terrae sp. nov., isolated from arid soil.

During the course of isolating rare actinobacteria from unexplored habitats, strain CH32T was obtained from an arid soil sample in eastern Anatolia, Turkey. Polyphasic characterization and comprehensive genome analyses showed that the strain is a member of the genus Nonomuraea and it is closely related to Nonomuraea gerenzanensis ATCC 39727T, Nonomuraea polychroma DSM 43925T and Nonomuraea maritima FXJ7.203T with gene identity level of 98.7%, 98.2% and 98.1%, respectively. The whole-cell hydrolysates contain meso-diaminopimelic acid as diagnostic diaminoacid and glucose, ribose, galactose, mannose and madurose as whole cell sugars. The predominant menaquinones are MK-9(H4), MK-9(H6) and MK-9(H2) while MK-9 exists as minor component. The polar lipid profile consists of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, glycolipid, glycophospholipids, phospholipids and unidentified lipids. The major cellular fatty acids are iso-C16:0 and C17:0 10-methyl. The total genome size is about 9.6 Mb and the G + C content is 71.0%. The genome contains biosynthetic gene clusters encoding for terpenes, siderophores, a type III polyketide synthase, a non-ribosomal polypeptide synthetase and a bacteriocin. The genome-based comparisons of the strain with its phylogenetic neighbours, as indicated by digital DNA-DNA hybridization and average nucleotide identity analyses, reveal that strain CH32T (= JCM 33876T = KCTC 49368T) is a novel member of the genus Nonomuraea, for which Nonomuraea terrae sp. nov. is proposed.

Serinicoccus hydrothermalis sp. nov., isolated from shallow-sea hydrothermal systems off Kueishantao Island.

A Gram-stain-positive, non-flagellated, non-gliding, coccoid bacterial strain, designated JLT9T, was isolated from the shallow-sea hydrothermal system off Kueishantao Island, Taiwan, ROC. Strain JLT9T was aerobic, chemoheterotrophic and grew optimally at 35 °C, at pH 6.0 and in the presence of 2.5 % (w/v) NaCl. Strain JLT9T exhibited highest 16S rRNA gene sequence similarity to Serinicoccus marinus DSM 15273T (98.83 %). Phylogenetic trees based on 16S rRNA gene sequences revealed that strain JLT9T belonged to the genus Serinicoccus, clustering with Serinicoccus marinus JC1078T, Serinicoccus profundi MCCC 1A05965T, Serinicoccus sediminis GP-T3-3T and Serinicoccus chungangensis CAU9536T. The digital DNA-DNA genome hybridization values between strain JLT9T and the closest related strain S. marinus DSM 15273T was 34.30 %. The DNA G+C content was 72.43 mol%. The dominant fatty acids were identified as iso-C15 : 0 (41.4 %) and iso-C16 : 0 (24.7 %). The polar lipids of strain JLT9T comprised diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, three unidentified glycolipid and an unidentified phospholipid. The predominant isoprenoid quinone was MK-8 (H4). The cell wall contained ornithine and serine, and no diaminopimelic acid. On the basis of phylogenetic data and several distinct phenotypic characteristics, strain JLT9T represents a novel species of the genus Serinicoccus, for which the name Serinicoccus hydrothermalis sp. nov. is proposed. The type strain is JLT9T (=CGMCC 1.15779T=JCM 31502T).

Glycomyces albidus sp. nov., a novel actinobacterium isolated from rhizosphere soil of wheat (Triticum aestivum L.).

A novel actinobacterium, designated strain NEAU-7082T, was isolated from rhizosphere soil of wheat (Triticum aestivum L.) and characterized by using a polyphasic approach. Morphological and chemotaxonomic characteristics confirmed the affiliation of strain NEAU-7082T to the genus Glycomyces. 16S rRNA gene sequence analysis indicated that strain NEAU-7082T belonged to the genus Glycomyces and was closely related to Glycomyces mayteni JCM 16217T (99.0 % 16S rRNA gene sequence similarity), Glycomyces sambucus DSM 45047T (98.4 %), Glycomyces scopariae DSM 44968T (98.3 %), Glycomyces paridis DSM 102295T (98.1 %), Glycomyces artemisiae NBRC 109773T (98.0 %) and Glycomyces dulcitolivorans DSM 105121T (97.9 %). Phylogenetic analysis using the 16S rRNA gene sequence showed that the strain formed a stable clade with G. mayteni JCM 16217T and clustered with G. sambucus DSM 45047T, G. scopariae DSM 44968T, G. artemisiae NBRC 109773T and G. dulcitolivorans DSM 105121T in the genus Glycomyces. The cell wall contained meso-diaminopimelic acid and the whole-cell hydrolysates were glucose and xylose. The polar lipid profile consisted of diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), glycolipid (GL), phosphatidylinositol mannoside (PIM) and an unidentified lipid (UL). The menaquinones were MK-11(H4), MK-11 and MK-10. Major fatty acids were anteiso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0. These chemotaxonomic data substantiated the affiliation of strain NEAU-7082T to the genus Glycomyces. The DNA G+C content was 71.3 mol%. A combination of DNA-DNA hybridization results and some phenotypic characteristics demonstrated that strain NEAU-7082T could be distinguished from its closest relatives. Therefore, strain NEAU-7082T is considered to represent a novel species of the genus Glycomyces, for which the name Glycomyces albidus sp. nov. is proposed. The type strain is NEAU-7082T (=CCTCC AA 2019045T=JCM 33458T).