INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY logo - Volume 70, Issue 11, 2020

A novel actinobacterium, designated strain K10HN5T, was isolated from a peat soil sample collected from Kantulee peat swamp forest, Surat Thani Province, Thailand and its taxonomic position was determined using a polyphasic approach. Strain K10HN5T contained meso-diaminopimelic acid, arabinose, galactose, glucose and ribose in its whole-cell hydrolysates. The predominant menaquinone was MK-8(H4). The major fatty acids were iso-C16 : 0, iso-C15 : 0 and iso-C16 : 1H. Mycolic acids were not present. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylmethylethanolamine, hydroxyphosphatidylethanolamine, hydroxyphosphatidylmethylethanolamine and phosphatidylinositol. The 16S rRNA gene sequence analysis indicated that it was closely related to Pseudonocardia bannensis DSM 45300T (97.9 %) and Pseudonocardia xinjiangensis JCM 11839T (97.9 %). Strain K10HN5T exhibited low average nucleotide identity and digital DNA–DNA hybridization values with P. bannensis DSM 45300T (82.6, 28.7 %) and P. xinjiangensis JCM11839T (76.3, 22.2 %). The DNA G+C content of strain K10HN5T was 72.4 mol%. Based on polyphasic data, strain K10HN5T represents a novel species of the genus Pseudonocardia , for which the name Pseudonocardia acidicola sp. nov. is proposed. The type strain is K10HN5T (=TBRC 10048T=NBRC 113897T).

A Gram-stain-positive, aerobic, motile, coccus-shaped bacterium, designated strain SCSIO 13315T, was isolated from mucus of the coral Galaxea sp. collected from Luhuitou fringing reef (Sanya, Hainan, PR China). Analysis of the 16S rRNA gene sequence showed that strain SCSIO 13315T exhibits 95.5 % 16S rRNA gene sequence similarity to Pseudokineococcus basanitobsidens SKC1-2T, 95.8 % to Pseudokineococcus lusitanus T2A-S27T and 96.4 % to Pseudokineococcus marinus KST3-3T. Results of phylogenetic analysis suggested that strain SCSIO 13315T was a member of the genus Pseudokineococcus . The DNA G+C content of strain SCSIO 13315T was 73.5 %. Chemotaxonomic assessment of strain SCSIO 13315T showed that the menaquinones were MK-8(H4) and MK-9(H2). The main cellular fatty acids were anteiso-C15 : 0, C16 : 0 and summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c). The polar lipids present were diphosphatidylglycerol, phosphatidylglycerol, two unknown phospholipids, four unidentified aminolipids and one unidentified lipid. Based on the phylogenetic and phenotypic analysis, it was evident that strain SCSIO 13315T represents a novel species of the genus Pseudokineococcus , for which the name Pseudokineococcus galaxeicola sp. nov. is proposed. The type strain is SCSIO 13315T (=NBRC 109944T=DSM 27812T).

Nine Gram-stain-positive cocci, coccobacilli or short, rod-shaped strains recovered from clinical sources from patients located in two Canadian provinces and one environmental source were extensively studied. Clinical sources included blood cultures, cerebral spinal fluid, lymph node, lung biopsy and peritoneal fluid. Through 16S rRNA gene and whole genome sequencing analyses, the strains were found to cluster into three groups, closest to but distinguished from other genera in the family Propionibacteriaceae . The genomes from these bacteria had high G+C content, ranging from 67.8–69.56 mol%, and genome sizes of 3.02–4.52 Mb. Biochemical and chemotaxonomic properties including branched-chain cellular fatty acids, l-lysine diaminopimelic acid (ll-DAP) and cell-wall type A3γ (ll-DAP-gly) containing ll-DAP, alanine, glycine and glutamic acid were found and so the strains were therefore deemed to be consistent with other new genera in this family. Based on this investigation, we propose Enemella gen. nov., Enemella evansiae sp. nov., Enemella dayhoffiae sp. nov. and Parenemella sanctibonifatiensis gen. nov., sp. nov. for these taxa. Misidentified taxon ‘Ponticoccus gilvus’ was found to be assignable to Enemella evansiae based on this study.

A Gram-stain-positive, non-motile, aerobic, rod-shaped, golden yellow-pigmented actinobacterium, designated strain YIM 123512T, was isolated from soil sampled at Gaoligong Mountain, Yunnan Province, PR China. The strain grew at 10–40 °C (optimum, 28 °C), with 0–3.0 % (w/v) NaCl (optimum, 0–1.0 %) and at pH 5.0–11.0 (optimum, pH 7.0). The major menaquinone was MK-8(H4) and the major cellular fatty acids (>10 %) were identified as iso-C16 : 0 and C17 : 1 ω8c. Strain YIM 123512T had ll-2, 6-diaminopimelic acid as the diagnostic cell-wall diamino acid. The major polar lipids were found to be diphosphatidylglycerol, phosphatidylglycerol, two unknown phospholipids and one unknown lipid. The genomic DNA G+C content of strain YIM 123512T was 72.7 mol% based on its draft genome sequence. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain YIM 123512T appeared to be most closely related to Nocardioides halotolerans KCTC 19274T (97.7 % sequence similarity) and to belong to the genus Nocardioides . The sequence similarity values of strain YIM 123512T to other currently described type strains of the genus Nocardioides were less than 97.0 %. Based on the draft genome sequence, the novel strain showed an average nucleotide identity value of 80.2 % and a digital DNA–DNA hybridization value of 23.1 % with the reference strain N. halotolerans KCTC 19274T. The results of the polyphasic taxonomic study including phenotypic, chemotaxonomic and phylogenetic analyses show that strain YIM 123512T represents a novel species of the genus Nocardioides , for which the name Nocardioides flavescens sp. nov. is proposed. The type strain is YIM 123512T (=KCTC 49303T=CGMCC 4.7628T).

The taxonomic position of a novel aerobic, Gram-positive actinobacteria, designated strain RB5T, was determined using a polyphasic approach. The strain, isolated from the gut of the fungus-farming termite Macrotermes natalensis, showed morphological, physiological and chemotaxonomic properties typical of the genus Streptomyces . Based on 16S rRNA gene sequence analysis, the closest phylogenetic neighbour of RB5T was Streptomyces polyrhachis DSM 42102T (98.87 %). DNA–DNA hybridization experiments between strain RB5T and S. polyrhachis DSM 42102T resulted in a value of 27.4 % (26.8 %). The cell wall of strain RB5T contained ll-diaminopimelic acid as the diagnostic amino acid. Mycolic acids and diagnostic sugars in whole-cell hydrolysates were not detected. The strain produced the following major phospholipids: diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol-mannoside and phosphatidylserine. The menaquinone profile showed hexa- and octahydrogenated menaquinones containing nine isoprene units [MK-9(H6) and MK-9(H8)]. The strain exhibited a fatty acid profile containing the following major fatty acids: 12-methyltridecanoic acid (iso-C14 : 0) 12-methyltetradecanoic acid (anteiso-C15 : 0), 13-methyltetradecanoic acid (iso-C15 : 0) and 14-methylpentadecanoic acid (iso-C16 : 0). Here, we propose a novel species of the genus Streptomyces – Streptomyces smaragdinus with the type strain RB5T (=VKM Ac-2839T=NRRL B65539T).

A new Gram-stain-positive, aerobic, non-motile and rod-shaped actinobacterium, designated O1T, was isolated from a deep-sea sediment of the Western Pacific Ocean. Strain O1T showed optimal growth at 30 °C, between pH 6.0 and 8.0, and in the presence of 1–5 % (w/v) NaCl. The predominant menaquinone was MK-8 (H2), and anteiso-C15 : 0 and anteiso-C17 : 0 were the major fatty acids. The diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and one unknown glycolipid. The DNA G+C content of strain O1T was 64.9 mol% and the genome size was 4.17 Mb. Based on a similarity search and phylogenetic analysis of the 16S rRNA gene sequence, strain O1T belonged to the genus Brevibacterium . The values of average nucleotide identity and in silico DNA–DNA hybridization between strain O1T and its close relatives were well below the thresholds used for the delineation of a new species. On the basis of the morphological and chemotaxonomic characteristics, as well as the genotypic data, it is proposed that strain O1T represents a novel species of the genus Brevibacterium , for which the name Brevibacterium profundi sp. nov. is proposed. The type strain is O1T (=JCM 33845T=MCCC 1A16744T).

A novel, Gram-stain-positive, aerobic, non-spore-forming, non-motile and irregular rod-shaped bacterium designated Q22T was isolated from the rhizosphere soil of mangrove plant, Kandelia candel collected in Zhangzhou, Fujian province, China. Strain Q22T was able to grow at 10–40 °C (optimum 30 °C), pH 5.5–9.0 (optimum 7.0–8.0) and with 0–5.0% (w/v) NaCl (optimum 1.0 %). The genomic DNA G+C content was 71.9%. The average nucleotide identity, and in silico DNA–DNA hybridization values between strain Q22T and the reference strains were 79.7–88.9% and 22.6–37.4%, respectively. The predominant isoprenoid quinone was MK-12 and the major fatty acids were anteiso-C15:0, iso-C16:0 and anteiso-C17:0. The major polar lipids of strain Q22T were diphosphatidylglycerol, phosphatidylglycerol, one glycolipid and three unidentified lipids. The strain Q22T contained 2,4-diaminobutyric acid, alanine acid, glutamic acid and glycine in the peptidoglycans. The phylogenetic analysis and genotypic features, along with the phenotypic and chemotaxonomic characteristics, indicate that strain Q22T represents a novel species of the genus Agromyces , for which the name Agromyces kandeliae sp. nov. is proposed. The type strain is Q22T (=MCCC 1K03340T= KCTC 39961T).

Two halophilic archaeal strains, C90T and YPL13T, were isolated from a salt lake and a salt mine in PR China. The two strains were found to form two clusters (97.5 and 89.5 % similarity between them, respectively) separating them from the three current members of the genus Natronomonas (95.4–97.0 % and 86.6–89.3 % similarity, respectively) on the basis of the 16S rRNA and rpoB′ gene sequence similarities and phylogenetic analysis. Diverse phenotypic characteristics differentiate strains C90T and YPL13T from current Natronomonas members. The polar lipids of strain C90T were phosphatidic acid, phosphatidylglycerol (PG), phosphatidylglycerol phosphate methyl ester (PGP-Me), phosphatidylglycerol sulphate, two unidentified glycolipids, a major glycolipid and a minor glycolipid, while those of strain YPL13T were PG, PGP-Me, two unidentified phospholipids and a glycolipid. The average nucleotide identity (ANI) and in silico DNA–DNA hybridization (isDDH) values between the two strains were 79.8 and 27.1 %, respectively, which were much lower than the threshold values proposed as a species boundaries (ANI 95–96 % and isDDH 70 %), which revealed that the two strains represent two novel species; these values (ANI 76.6–80.0 % and isDDH 21.6–27.0 %) of the strains examined in this study and the current members of Natronomonas are much lower than the recommended threshold values, suggesting that strains C90T and YPL13T represent two genomically different species of Natronomonas . These results showed that strains C90T (=CGMCC 1.13738T=JCM 32961T) and YPL13T (=CGMCC 1.13884T=JCM 31111T) represent two novel species of Natronomonas , for which the names Natronomonas halophila sp. nov. and Natronomonas salina sp. nov. are proposed.

A novel Gram-stain-negative, non-endospore-forming, non-motile, aerobic bacterium (strain R33T) was isolated from coral Porites lutea and subjected to a polyphasic taxonomic study. The G+C content was 44.5 mol%. The only detected respiratory quinone was menaquinone 6 (MK-6). The major cellular fatty acids were iso-C15 : 0 and iso-C15 : 1 ω6c. The major polar lipids were phosphatidylethanolamine and two unidentified lipids. Global alignment based on 16S rRNA gene sequences indicated that strain R33T shares the highest sequence identity of 93.2 % with Muriicola marianensis A6B8T in the family Flavobacteriaceae . Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain R33T forms a distinct branch in a stable clade comprising strain R33T and members of the genera Muriicola , Robiginitalea , Eudoraea and Zeaxanthinibacter . The phylogenomic analysis also supported this 16S rRNA gene-based phylogenetic result. Comparative genomic analysis indicated that strain R33T is rich in AraC-type DNA-binding domain-containing protein-coding genes, which means the regulation of carbon utilization is very complex. Low 16S rRNA gene identity, different polar lipids and/or cellular fatty acid profiles could readily distinguish strain R33T from any validly published type strains. Therefore, strain R33T is suggested to represent a new species in a new genus, for which the name Poritiphilus flavus gen. nov., sp. nov. is proposed. The type strain is R33T (=MCCC 1K03853T=KCTC 72443T).

Two anaerobic bacteria, designated strains SYSU GA16112T and SYSU GA16107, were isolated from a hot spring in Tengchong County, Yunnan Province, south-west PR China. Phylogenetic analyses based on 16S rRNA gene sequences showed that strains SYSU GA16112T and SYSU GA16107 belong to the family Dysgonamonadaceae. Cells of strains SYSU GA16112T and SYSU GA16107 were Gram-stain-negative, rod-shaped and non-motile. The major fatty acids (>10 %) of strains SYSU GA16112T and SYSU GA16107 were identified as anteiso-C15 : 0 and anteiso-C17 : 0 3OH. The polar lipid profile of strain SYSU GA16112T was found to consist of phosphatidylethanolamine, two unidentified aminophospholipids, two unidentified phosphoglycolipids, two unidentified aminolipids and one unidentified polar lipid, while that of strain SYSU GA16107 consisted of phosphatidylethanolamine, two unidentified polar lipids, three unidentified aminophospholipids, two unidentified phosphoglycolipids and one unidentified aminolipid. The genomic DNA G+C contents of strains SYSU GA16112T and SYSU GA16107 were determined to be 41.90 and 41.89 %, respectively, and the average nucleotide identity value between them was 99.99 %. Based on their morphological and physiological properties, and results of phylogenetic analyses, strains SYSU GA16112T and SYSU GA16107 are considered to represent a novel species of a novel genus, for which the name Seramator thermalis gen. nov., sp. nov. (type strain SYSU GA16112T=CGMCC 1.5281T=KCTC 15753T) is proposed.

A novel bacterial strain of the family ‘Vicingaceae’ was isolated from mangrove of Tielu Harbour, Hainan, PR China. Strain S-15T was a Gram-stain-negative, short-rod-shaped, yellow-pigmented that could grow at 10–42 °C (optimum, 26–35 °C), at pH 5.0–9.0 (optimum, pH 5.5) and in 0.5–10.0 % w/v sea salt (optimum, 3.5–4.0 %). Cells of strain S-15T were 0.9–1.4 μm long, 0.8–0.9 μm wide, catalase-positive and oxidase-positive. Colonies on modified marine agar 2216 were 0.5–2.0 mm in diameter after incubation for 72 h at 28 °C. Analysis of 16S rRNA gene sequences revealed that strain S-15T was most closely related to Vicingus serpentipes ANORD5T (89.8 %). The major respiratory quinone of strain S-15T was menaquinone MK-7, and the dominant fatty acids were C15:0 iso, C15:1 iso G and C17:0 iso 3-OH. The major polar lipids were two unidentified aminolipids, phosphatidylethanolamine and six unidentified lipids. Analyses showed that the genome size was 3.52 Mb and the DNA G+C content was 35.6 mol%, which were higher than V. serpentipes ANORD5T with 2.92 Mb genome size and 31.0 mol% G+C content, respectively. Based on morphological, physiological and phylogenetic data, strain S-15T is considered a type strain of a new species and a new genus of the family ‘Vicingaceae’ for which the name Acidiluteibacter ferrifornacis gen. nov., sp. nov. is proposed. The type strain of Acidiluteibacter ferrifornacis is S-15T (=MCCC 1K03817T=JCM 33804T).

A Gram-staining-negative non endospore-forming strain, PXU-55T, was isolated from the rhizosphere of the switchgrass Panicum virgatum and studied in detail to determine its taxonomic position. The results of 16S rRNA gene sequence analysis indicated that the isolate represented a member of the genus Flavobacterium . The isolate shared highest 16S rRNA gene sequence similarities with the type strains of Flavobacterium chungangense (98.78 %) and Flavobacterium chilense (98.64 %). The average nucleotide identity (ANI) and in silico DNA–DNA hybridization (isDDH) values between the PXU-55T genome assembly and the ones of the most closely related type strains of species of the genus Flavobacterium were 87.3 and 31.9% ( Flavobacterium defluvii ), and 86.1 and 29.9% ( Flavobacterium johnsoniae ). Menaquinone MK-6 was the major respiratory quinone. As major polar lipids, phosphatidylethanolamine, an ornithine lipid and the unidentified polar lipids L2, L3 and L4 lacking a functional group were found. Moderate to minor amounts of another ornithine lipid, the unidentified lipid L1 and a glycolipid were present, as well. The major polyamine is sym-homospermidine. The fatty acid profiles contained major amounts of iso-C15:0, iso-C15:0 3-OH, iso-C17:0 3-OH, C15:0, summed feature 3 (C16:1ω7c and/or iso-C15:0 2-OH) and various hydroxylated fatty acids in smaller amounts, among them iso C16:0 3-OH, C16:0 3-OH and C15:0 3-OH, which supported the classification of the isolate as a member of the genus Flavobacterium . Physiological and biochemical characterisation and ANI calculations with the type strains of the most closely related species allowed a clear phenotypic and genotypic differentiation of the strain. For this reason, we propose that strain PXU-55T (=CIP 111646T=CCM 8914T) represents a novel species with the name Flavobacterium panici sp. nov.

A Gram-stain-negative, strictly aerobic, motile by gliding, rod-shaped and non-flagellated marine bacterium strain, designated BOM4T, was isolated from a mussel inhabiting the Tangyin hydrothermal field of the Okinawa Trough. The growth temperature was in the range of 16–40 °C, and the optimum temperature was 37 °C. Optimal growth occurred at pH 7.0 and in the presence of 1 % (w/v) NaCl. The predominant isoprenoid quinone of strain BOM4T was identified as menaquinone-6 (MK-6). The predominant fatty acids (>10 %) were iso-C15 : 0(43.8 %) and iso-C17 : 0 3-OH (17.5 %). The major polar lipids comprised one phosphatidylethanolamine, three unidentified aminolipids and two unidentified lipids. Based on 16S rRNA gene sequence analyses, strain BOM4T was found to be most closely related to Gramella aestuarii JCM 17790T (96.7 %), followed by Gramella flava JLT2011T (96.1 %), Gramella sediminilitoris GHTF-27T (95.6 %) and Gramella gaetbulicola RA5-111T (95.5 %) and with lower sequence similarities (93.7- 95.4 %) to other species of the genus Gramella . Genome relatedness between strain BOM4T and G. aestuarii JCM 17790T was computed using both average nucleotide identity and DNA–DNA hybridization with values of 75.6 and 19.3±2.4 %, respectively. The DNA G+C content of strain BOM4T was 41.4 mol%. On the basis of polyphasic analysis, strain BOM4T was considered to represent a novel species of the genus Gramella , for which the name Gramella bathymodioli sp. nov. is proposed. The type strain is BOM4T (=MCCC 1K03735T=JCM 33424T).

A novel Gram-stain-negative, strictly aerobic, rod-shaped, brick red-pigmented bacterium, designated R-22-1 c-1T, was isolated from water from Baiyang Lake, Hebei Province, PR China. The strain was able to grow at 20–30 °C (optimum, 30 °C) and pH 6–7 (optimum, pH 6) in Reasoner’s 2A medium. 16S rRNA gene sequence and phylogenetic analyses of R-22-1 c-1T revealed closest relationships to Rufibacter immobilis MCC P1T (97.8 %), Rufibacter sediminis H-1T (97.9 %) and Rufibacter glacialis MDT1-10-3T (97.0 %), with other species of the genus Rufibacter showing less than 97.0 % sequence similarity. The predominant polar lipids were phosphatidylethanolamine, two unidentified aminophospholipids and three unidentified lipids. The major cellular fatty acids were iso-C15 : 0, C15 : 1 ω6c, C17 : 1 ω6c, anteiso-C15 : 0, summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1 ω7c and/or C16 : 1 ω6c) and summed feature 4 (iso-C17 : 1I and/or anteiso-C17 : 1B). The respiratory quinone was MK-7. The draft genome of R-22-1 c-1T was 5.6 Mbp in size, with a G+C content of 50.2 mol%. The average nucleotide identity and digital DNA–DNA hybridization relatedness values between strain R-22-1 c-1T and related type strains were R. immobilis MCC P1T (77.2 and 21.8 %), R. sediminis H-1T (81.6 and 21.4 %) and R. tibetensis 1351T (78.5 and 22.9 %). Based on these phylogenetic, chemotaxonomic and genotypic results, strain R-22-1 c-1T represents a novel species in the genus Rufibacter , for which the name Rufibacter latericius sp. nov. is proposed. The type strain is R-22-1 c-1T (=CGMCC 1.13570T=KCTC 62781T).

A taxonomic identification using a polyphasic approach was performed on strain NBS58-1T, which was isolated from the interfacial sediment of Taihu Lake in China. Strain NBS58-1T was Gram-stain-negative, aerobic, non-spore-forming and catalase-positive. Phylogenetic analyses based on 16S rRNA gene and three housekeeping genes (rpoB, gyrB and dnaK) sequences supported the position that strain NBS58-1T should be classified within the genus Rufibacter . The 16S rRNA gene sequence of strain NBS58-1T possessed the highest similarity to Rufibacter sediminis H-1T (96.60 %), followed by Rufibacter glacialis MDT1-10-3T (96.17 %). And the ANI value between strain NBS58-1T and R. glacialis MDT1-10-3T was 79.3 %. The respiratory quinone was menaquinone 7 (MK-7). The major cellular fatty acids comprised iso-C15 : 0 and summed feature 3. Phosphatidylethanolamine, two unidentified phospholipids and four unidentified lipids were the main polar lipids. The genomic DNA G+C content was 51.3 mol%. Based on phenotypic features and phylogenetic position, a novel species with the name Rufibacter hautae sp. nov. is proposed. The type strain is NBS58-1T=(KACC 21309T=MCCC 1K04037T). We also proposed Rufibacter quisquiliarum as a latter heterotypic synonym of Rufibacter ruber .

Strain CFH S0501T, a novel Gram-stain-positive, aerobic, rod-shaped, endospore-forming and motile micro-organism with peritrichous flagella, was isolated from a sediment sample collected from the Yellow River in Henan Province, PR China. Optimum growth was observed at 28 °C, pH 7.0 and without NaCl. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that the strain belonged to the genus Brevibacillus and was closely related to Brevibacillus centrosporus DSM 8445T and Brevibacillus ginsengisoli Gsoil 3088T (with 96.8 and 96.7 % sequence similarity, respectively). The predominant menaquinone was MK-7. Major cellular fatty acids were anteiso-C15 : 0 and iso-C15 : 0. Polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, two unidentified phospholipids and an unidentified polar lipid. The cell-wall peptidoglycan was found to contain meso-diaminopimelic acid. The genome size was 5.26 Mbp with a G+C content of 49.7 mol%. The average nucleotide identity (ANI) and in silico DNA–DNAhybridization (DDH) values between CFH S0501T and the other species of the genus Brevibacillus were found to be low (ANIm <86.11 %, ANIb <70.30 % and DDH <25.00 %). Based on physiological properties, chemotaxonomic characteristics and low ANI and DDH results, strain CFH S0501T is considered to represent a novel species, for which the name Brevibacillus migulae sp. nov. is proposed. The type strain is CFH S0501T (=DSM 29940T=BCRC 80809T).