Ruicaihuangia caeni gen. nov., sp. nov., a novel taxon within the family Microbacteriaceae isolated from sludge.

A Gram-stain-positive bacterium, designated YN-L-19T, was isolated from a sludge sample collected from a pesticide-manufacturing plant. Cells of YN-L-19T were strictly aerobic, non-spore-forming, non-motile and ovoid-shaped. Colonies were small, smooth and yellow. Growth occurred at 10-37 °C (optimum, 30 °C), pH 5.0-9.0 (optimum, 7.0) and 0-3.0 % (w/v) NaCl (optimum 0.5 %). Phylogenetic analysis based on genome and 16S rRNA gene sequences indicated that YN-L-19T was affiliated to the family Microbacteriaceae and most closely related to Diaminobutyricimonas aenilata, Terrimesophilobacter mesophilus, Planctomonas deserti and Curtobacterium luteum. The major cellular fatty acids of YN-L-19T were anteiso-C15 : 0, anteiso-C17 : 0, iso-C16 : 0 and C16 : 0. The predominant menaquinone was MK-7. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, glycolipid and one unidentified lipid. The average amino acid identity values between strain YN-L-19T and the related strains were 57.9-61.9 %, which were below the genus boundary (70 %). On the basis of the evidence presented in this study, strain YN-L-19T represents a novel species of a new genus in the family Microbacteriaceae, for which the name Ruicaihuangia caeni gen. nov., sp. nov. (type strain YN-L-19T=CCTCC AB 2022401T= KCTC 49935T) is proposed.

Sciscionella sediminilitoris sp. nov., a Marine Actinomycete Isolated from Cape Rochado, Malaysia, and the Emendations to the Description of the Genus Sciscionella.

In this study, we employed a polyphasic approach to determine the taxonomic position of a newly isolated actinomycete, designated SE31T, obtained from a sediment sample collected at Cape Rochado, Malaysia. Phylogenetic analysis of the 16S rRNA gene sequence revealed that strain SE31T belonged to the family Pseudonocardiaceae and exhibited the highest sequence similarity (98.9%) to Sciscionella marina. Further genomic analysis demonstrated a 93.4% average nucleotide identity and 54.4% digital DNA-DNA hybridization relatedness between strain SE31T and S. marina. The chemotaxonomic characteristics of strain SE31T were typical of the genus Sciscionella, including cell-wall chemotype IV (with meso-diaminopimelic acid as the diagnostic diamino acid, and arabinose and galactose as whole-cell sugars). The identified polar lipids of strain SE31T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmethylethanolamine, and hydroxyphosphatidymethylethanolamine. The primary menaquinone observed was MK-9(H4), and the major cellular fatty acid was iso-C16:0. The genomic DNA size of strain SE31T was determined to be 7.4 Mbp with a G+C content of 68.7%. Based on these comprehensive findings, strain SE31T represents a novel species within the genus Sciscionella, in which the name Sciscionella sediminilitoris sp. nov. is proposed. The type strain of Sciscionella sediminilitoris is SE31T (= DSM 46824T = TBRC 5134T).

Maribacter halichondriae sp. nov., isolated from the marine sponge Halichondria panicea, displays features of a sponge-associated life style.

A new member of the family Flavobacteriaceae (termed Hal144T) was isolated from the marine breadcrumb sponge Halichondria panicea. Sponge material was collected in 2018 at Schilksee which is located in the Kiel Fjord (Baltic Sea, Germany). Phylogenetic analysis of the full-length Hal144T 16S rRNA gene sequence revealed similarities from 94.3 to 96.6% to the nearest type strains of the genus Maribacter. The phylogenetic tree of the 16S rRNA gene sequences depicted a cluster of strain Hal144T with its closest relatives Maribacter aestuarii GY20T (96.6%) and Maribacter thermophilus HT7-2T (96.3%). Genome phylogeny showed that Maribacter halichondriae Hal144T branched from a cluster consisting of Maribacter arenosus, Maribacter luteus, and Maribacter polysiphoniae. Genome comparisons of strain Maribacter halichondriae Hal144T with Maribacter sp. type strains exhibited average nucleotide identities in the range of 75-76% and digital DNA-DNA hybridisation values in the range of 13.1-13.4%. Compared to the next related type strains, strain Hal144T revealed unique genomic features such as phosphoenolpyruvate-dependent phosphotransferase system pathway, serine-glyoxylate cycle, lipid A 3-O-deacylase, 3-hexulose-6-phosphate synthase, enrichment of pseudogenes and of genes involved in cell wall and envelope biogenesis, indicating an adaptation to the host. Strain Hal144T was determined to be Gram-negative, mesophilic, strictly aerobic, flexirubin positive, resistant to aminoglycoside antibiotics, and able to utilize N-acetyl-ß-D-glucosamine. Optimal growth occurred at 25-30 °C, within a salinity range of 2-6% sea salt, and a pH range between 5 and 8. The major fatty acids identified were C17:0 3-OH, iso-C15:0, and iso-C15:1 G. The DNA G + C content of strain Hal144T was 41.4 mol%. Based on the polyphasic approach, strain Hal144T represents a novel species of the genus Maribacter, and we propose the name Maribacter halichondriae sp. nov. The type strain is Hal144T (= DSM 114563T = LMG 32744T).

Speluncibacter jeojiensis gen. nov. sp. nov., a novel bacterium of the order Mycobacteriales isolated from a cave and a proposal of Speluncibacteraceae fam. nov.

Two Gram-stain-positive, aerobic, non-spore-forming, non-motile, irregular rod-shaped actinobacteria, designated as D2-41T and D3-21, were isolated from soil samples collected in a natural cave in Jeju, Republic of Korea. Both of the isolates were shown to share 100 % 16S rRNA sequence identity. The cell wall contained meso-diaminopimelic acid, arabinose and galactose. The predominant menaquinone was MK-8(H2). The polar lipids contained phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, an unidentified aminolipid, an unidentified aminoglycolipid, an unidentified phospholipid and two unidentified lipids. The predominant fatty acids were C16 : 0 and summed feature 3 (C16 : 1 ω7c and/or iso-C15 : 0 2-OH). Mycolic acids of C30-C38 were present. The 16S rRNA gene trees showed that the organisms occupied a distinct position remotely located from recognized genera within the order Mycobacteriales, albeit with the 16S rRNA gene similarities of 97.0-97.1 % with Rhodococcus olei, Rhodococcus rhodnii and Rhodococcus triatomae. The genome sizes and DNA G+C contents of strains D2-41T and D3-21 were 4.77-4.88 Mbp and 69.8 mol%, respectively. Both of the isolates shared an average nucleotide identity of 99.4 % and digital DNA-DNA hybridization of 95.2 % to each other, revealing that strains D2-41T and D3-21 belonged to the same species. In the core genome-based phylogenomic tree, both of the isolates were found to be closely associated with members of the genus Tomitella. However, strains D2-41T and D3-21 revealed the highest amino acid identity values (mean 66.5 %, range 66.2-67.0 % with the genus Prescottella of the family Nocardiaceae, followed by the genus Tomitella (mean 64.1 %, range 63.6-64.7 %) of the family Tomitellaceae. Based on the combined data obtained here, the novel isolates belong to a new genus of the new family for which the name Speluncibacter jeojiensis gen. nov. sp. nov. is proposed, with Speluncibacteraceae fam. nov. The type strain is strain D2-41T (=KACC 17930T=DSM 101875T).

Analysis of vitamin K1 and major K2 variants in rat/human serum and lipoprotein fractions by a rapid, simple, and sensitive UHPLC-MS/MS method.

Determination of the various forms of vitamin K, which are involved in coagulation and other physiological processes in humans, is challenging and no standardized method is yet available. Therefore, a reliable and practical method was developed to quantify vitamin K levels in serum and additionally in lipoprotein fractions to clarify its distribution. The LC-MS/MS method for the determination of vitamin K1 and the three main isoforms of vitamin K2 (MK-4, MK-7, MK-9) was combined with a gradient ultracentrifugation technique to allow the separation of lipoprotein fractions. The chromatographic separation was carried out on a Kinetex™ C18 column using a mobile phase consisting mainly of methanol. The target analytes were detected by electrospray ionization mass spectrometry. The separation of all four substances was achieved after a simple sample preparation technique based on miniaturized liquid-liquid extraction. Our method of only 8.5 min revealed the levels of the major forms of vitamin K in 59 human and 12 rat sera and confirmed our hypothesis that vitamin K is primarily (about 50 %) found in the high-density lipoprotein fraction. The median concentrations of vitamin K1, MK-4, MK-7, and MK-9 were found to be 1.19, 2.98, 0.43, and < 0.71 nmol/L in human serum and 1.74, 6.75, less than 0.2, and less than 0.5 nmol/L in rat serum, respectively.

Chryseobacterium pyrolae sp. nov., isolated from the rhizosphere soil of Pyrola calliantha H.

A novel Gram-stain-negative, aerobic, non-motile, rod-shaped bacterium, designated pc2-12T, was isolated from the rhizosphere soil of the herb Pyrola calliantha collected from arid areas of Tibet. The strain grew most vigorously with 1 % (w/v) NaCl, at pH 7.0 and at 25 °C. According to the results of 16S rRNA gene sequence analysis, pc2-12T was closely related to the members of the genus Chryseobacterium, with highest levels of sequence similarity to Chryseobacterium viscerum 687B-08T (98.42 %), Chryseobacterium oncorhynchi 701B-08T (98.11 %) and Chryseobacterium ureilyticum DSM 18017T (97.98 %). The average nucleotide identity values between pc2-12T and C. viscerum 687B-08T, C. oncorhynchi 701B-08T and C. ureilyticum DSM 18017T were 79.71, 79.49 and 79.26 %, respectively. The in silico DNA-DNA hybridisation values between pc2-12T and C. viscerum 687B-08T, C. oncorhynchi 701B-08T and C. ureilyticum DSM 18017T were 23.30, 23.00 and 22.90 %, respectively. The draft genome sequence of pc2-12T was 4.64 Mb long, with DNA G+C content of 37.0 mol%. The fatty acids contained in the cells of pc2-12T were mainly composed of iso-C15 : 0, iso-C17 : 0 3-OH and summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c). The main polar lipid was phosphatidylethanolamine. MK-6 was the sole respiratory quinone. On the basis of the results of analysis of all the data described, pc2-12T is considered to represent a novel species of the genus Chryseobacterium, for which the name Chryseobacterium pyrolae sp. nov., is proposed. The type strain is pc2-12T (=GDMCC 1.3256T= JCM 35712T).

Flavobacterium sedimenticola sp. nov., isolated from sediment.

A novel yellow-pigmented bacterial strain, designated YZ-48T, was isolated from the sediment of the Yangtze River, PR China. Cells were Gram-stain-negative, non-motile, rod-shaped, strictly aerobic, catalase-positive and oxidase-positive. The strain grew optimally on R2A medium at 37 °C, pH 7.0 and with 1.0 % (w/v) NaCl. Strain YZ-48T showed the closest 16S rRNA gene sequence similarity to Flavobacterium solisilvae SE-s27T (96.4 %) and F. dankookense DSM 25687T (96.2 %). The phylogenetic trees based on 16S rRNA gene sequences showed that strain YZ-48T belonged to the genus Flavobacterium but formed a distinct phylogenetic lineage. The obtained average nucleotide identity and digital DNA-DNA hybridization values between YZ-48T and the two closest strains were 75.0 and 74.5 % and 19.6 and 19.0 %, respectively. The sole respiratory quinone was MK-6. The major polar lipids were phosphatidylethanolamine, two unidentified aminolipids and three unidentified polar lipids. The major cellular fatty acids were iso-C16 : 0, iso-C15 : 0, iso-C15 : 1 G, iso-C17 : 0 3-OH, iso-C15 : 0 3-OH and iso-C16 : 0 3-OH. The DNA G+C content was 40.2 mol%. Based on the phenotypic, chemotaxonomic, phylogenetic and genomic data, strain YZ-48T represents a novel species of the genus Flavobacterium, for which the name Flavobacterium sedimenticola sp. nov. is proposed, with strain YZ-48T (=KCTC 82329T=CCTC AB 2023061T=MCCC 1K08804T) as the type strain.

Thermobacterium salinum gen. nov., sp. nov., a novel member of the family Flavobacteriaceae isolated from a hydrothermal zone.

A Gram-stain-negative, aerobic, non-motile and rod-shaped bacterial strain, designated as strain TK19130T, was isolated from the Lonqi hydrothermal zone in the Southwest Indian Ridge. Growth occurred with 1-12 % (w/v) NaCl (optimum, 2-4 %), at 10-40 °C (optimum, 30-35 °C) and at pH 6.0-9.0 (optimum, pH 7.0-8.0). The genome of strain TK19130T was 3.15 Mb, with a DNA G+C content of 41.35 %. Based on the results of 16S rRNA gene sequence analysis, strain TK19130T was affiliated with the family Flavobacteriaceae, in which the highest similarity was 90.54 % to Aureisphaera salina A6D-50T, under the genus demarcation boundary (94.50 %). Average nucleotide identity values between strain TK19130T and adjacent strains were 67.17-72.00 %, lower than the recommended threshold of 73.98 % for genus delineation. The predominant respiratory quinone of strain TK19130T was menaquinone 6. Major polar lipids were phosphatidylethanolamine, three aminolipids and one unidentified polar lipid. Major fatty acids were detected as iso-C15 : 1 G, iso-C15 : 0 and iso-C17 : 0 3-OH. Based on the polyphasic taxonomic evidence presented above, strain TK19130T formed an independent branch representing a new species of a novel genus within the family Flavobacteriaceae, for which the name Thermobacterium salinum gen. nov., sp. nov. is proposed. The type strain is TK19130T (=CGMCC 1.18993T=JCM 35842T=MCCC M28200T).

Muricauda myxillae sp. nov., isolated from a marine sponge (Myxilla rosacea), and reclassification of Flagellimonas hymeniacidonis as Muricauda symbiotica nom. nov.

A Gram-stain-negative, aerobic and non-motile rods strain, designated as strain 2012CJ39-3T, was isolated from a marine sponge, Myxilla rosacea, collected on Chuja Island, Republic of Korea. Optimal growth of strain 2012CJ39-3T was observed at 25 °C, pH 7.0 and in the presence of 2.0-3.0 % (w/v) NaCl. Strain 2012CJ39-3T contained menaquinone-6 as the respiratory quinone, iso-C15 : 1 G, iso-C15 : 0, and iso-C17 : 0 3-OH as the predominant fatty acids, and phosphatidylethanolamine, an unidentified phospholipid, an unidentified glycolipid, three unidentified aminolipids and nine unidentified lipids as major polar lipids. The genomic DNA G+C content was 38.4 mol%. Results of phylogenetic analyses based on the 16S rRNA gene and whole-genome sequences revealed that strain 2012CJ39-3T formed a distinct phyletic lineage in the genus Muricauda. Strain 2012CJ39-3T was most closely related to Flagellimonas hymeniacidonis 176CP5-101T, Muricauda spongiicola 2012CJ35-5T, Muricauda algicola AsT0115T, Muricauda flava DSM 22638T and Muricauda parva SW169T with 96.5, 96.4, 96.3, 95.8 and 95.6 % 16S rRNA gene sequence similarity, respectively. The average nucleotide identity and digital DNA-DNA hybridization values between strain 2012CJ39-3T and M. spongiicola 2012CJ35-5T, F. hymeniacidonis 176CP5-101T, M. algicola AsT0115T, M. flava DSM 22638T and M. parva SW169T were 75.6, 74.2, 78.6, 75.3 and 74.8 % and 27.4, 19.9, 36.3, 24.2 and 18.9 %, respectively. Based on these results, strain 2012CJ39-3T represents a novel species of the genus Muricauda, for which the name Muricauda myxillae sp. nov. is proposed. The type strain is 2012CJ39-3T (=KACC 22644T= LMG 32582T). In addition, Flagellimonas hymeniacidonis is reclassified as Muricauda symbiotica nom. nov.

Parabacteroides leei sp. nov., isolated from human blood.

An obligate anaerobic, Gram-negative, rod-shaped and non-spore-forming bacterium, designated as strain GYB001T, was isolated from the blood of a patient with a sigmoid colon perforation. Taxonomic characterization of the novel isolate was performed using a polyphasic approach. A phylogenetic analysis based on 16S rRNA gene and whole genome sequences revealed that GYB001T represented a member of the genus Parabacteroides, in the family Tannerellaceae. The closest species, based on 16S rRNA sequence, was Parabacteroides gordonii DSM 23371T with 97.4 % similarity. Average nucleotide identity and digital DNA-DNA hybridization values between strain GYB001T and P. gordonii DSM 23371T were 86.7 and 28.7% and between GYB001T and Parabacteroides faecis JCM 18682T were 86.6 and 27.7 %, respectively. The genome was 6.57 Mbp long with 43.3 mol% G+C content. Colonies on Brucella blood agar (BBA) were circular, convex, smooth, grey and small in size. Growth was observed on trypticase soy agar (TSA), TSA +5 % sheep blood and Euglena gracilis agar. Growth occurred at 18-42 °C on BBA in the presence of 0-3 % NaCl (w/v) and at pH 6.0-8.5. The major polar lipids were phosphatidylethanolamine and phospholipids. The major fatty acids in strain GYB001T were anteiso-C15 : 0 and iso-C17 : 0 3-OH, and the predominant respiratory quinones were menaquinone-10 (MK-10) and MK-9. The cell wall contained meso-diaminopimelic acid. Considering these phenotypic features and comparative genome analyses, we propose strain GYB001T as the type strain of Parabacteroides leei sp. nov. (=KCTC 25738T=KBN12P06525T=LMG 32797T).

Psychrobacillus antarcticus sp. nov., a psychrotolerant bioemulsifier producer isolated from King George Island, Antarctica.

A Gram-stain-positive rod, psychrotolerant, aerobic and bioemulsifier-producing strain, denoted as Val9T, was isolated from soil sampled at Vale Ulman, King George Island, Antarctica. The strain grew at up to 30 °C (optimum, 15 °C), at pH 6-9 (optimum, pH 8) and with up to 5 % w/v NaCl (optimum, 3 %). The strain was motile and positive for catalase, oxidase and H2S. It did not hydrolyse starch, casein or gelatin. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain Val9T belonged to the genus Psychrobacillus and was closely related to Psychrobacillus psychrotolerans DSM 11706T (99.9 % similarity), Psychrobacillus psychrodurans DSM 11713T (99.8 %) and Psychrobacillus glaciei PB01T (99.2 %). Digital DNA-DNA hybridization and average nucleotide identity values were lower than 37.3 and 85.5 %, respectively, with the closest phylogenetic neighbours. The DNA G+C content of strain Val9T calculated from the complete genome sequence was 36.6 mol%. The predominant cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0 and anteiso-C17 : 1ω11c. Menaquinone-8 was the major respiratory quinone. The peptidoglycan type was A4ß l-Orn-d-glu. The novel strain contained diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol as predominant polar lipids. Based on 16S rRNA phylogenetic and multilocus sequence analyses (recA, rpoB and gyrB), as well as phylogenomic, chemotaxonomic and phenotypic tests, we demonstrate that strain Val9T represents a novel species of the genus Psychrobacillus, for which the name Psychrobacillus antarcticus sp. nov. is proposed. The type strain is Val9T (=DSM 115096T=CCGB 1952T=NRRL B-65674T).

Arthrobacter zhaoxinii sp. nov. and Arthrobacter jinronghuae sp. nov., isolated from Marmota himalayana.

Four yellow-coloured strains (zg-Y815T/zg-Y108 and zg-Y859T/zg-Y826) were isolated from the intestinal contents of Marmota himalayana and assigned to the 'Arthrobacter citreus group'. The four strains grew optimally on brain heart infusion agar with 5 % defibrinated sheep blood plate at 30 °C, pH 7.0 and with 0.5 % NaCl (w/v). Comparative analysis of their 16S rRNA genes indicated that the two strain pairs belong to the genus Arthrobacter, showing the highest similarity to Arthrobacter yangruifuii 785T (99.52 %), which was further confirmed by the 16S rRNA gene and genome-based phylogenetic analysis. The comparative genomic analysis [digital DNA-DNA hybridization, (dDDH) and average nucleotide identity (ANI)] proved that the four strains are two different species (zg-Y815T/zg-Y108, 71.7 %/96.8 %; zg-Y859T/zg-Y826, 87.3 %/98.5 %) and differ from other known species within the genus Arthrobacter (zg-Y815T, 19.6-32.3 %/77.2-88.0 %; zg-Y859T, 19.5-29.3 %/77.4-86.3 %). Strain pairs zg-Y815T/zg-Y108 and zg-Y859T/zg-Y826 had the same major cellular fatty acids (iso-C16 : 0 and anteiso-C15 : 0), with MK-8(H2) as their dominant respiratory quinone (70.6 and 61.7 %, respectively). The leading polar lipids were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylinositol. The detected amino acids and cell-wall sugars of the two new species were identical (amino acids: alanine, glutamic acid, and lysine; sugars: rhamnose, galactose, mannose, glucose, and ribose). According to the phylogenetic, phenotypic, and chemotaxonomic analyses, we concluded that the four new strains represented two different novel species in the genus Arthrobacter, for which the names Arthrobacter zhaoxinii sp. nov. (zg-Y815T= GDMCC 1.3494T = JCM 35821T) and Arthrobacter jinronghuae sp. nov. (zg-Y859T = GDMCC 1.3493T = JCM 35822T) are proposed.

Two novel alkalitolerant species Pseudalkalibacillus spartinae sp. nov. and Pseudalkalibacillus sedimenti sp. nov.

In this study, two novel alkalitolerant strains (FJAT-53046T and FJAT-53715T) were isolated from sediment samples collected in Zhangzhou, PR China. Phylogeny based on 16S rRNA gene sequences suggested that strains FJAT-53046T and FJAT-53715T were new members of the genus Pseudalkalibacillus. The two novel strains showed the highest 16S rRNA gene sequence similarity to Pseudalkalibacillus hwajinpoensis DSM 16206T, with values of 97.4 and 97.6 %, respectively. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the two strains and the reference strain were 77.2 and 79.6 %, 20.9 and 30.2 %, respectively, which were below the prokaryotic species delineation thresholds. The ANI and dDDH values between strains FJAT-53046T and FJAT-53715T were 86.0 and 30.2 %, respectively, suggesting that they belonged to different species in the genus Pseudalkalibacillus. The major respiratory quinone in both strains was MK-7 and the major cellular fatty acids were anteiso-C15 : 0 and anteiso-C17 : 0. Diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine were the major polar lipids in both novel strains. Combined with results stemming from the determination of physical and biochemical characteristics, chemical properties, and genome analysis, strains FJAT-53046T and FJAT-53715T are proposed to represent two novel species of the genus Pseudalkalibacillus, for which the names Pseudalkalibacillus spartinae sp. nov. and Pseudalkalibacillus sedimenti sp. nov. are proposed. The type strains are FJAT-53046T (=GDMCC 1.3077T=JCM 35611T) and FJAT-53715T (=GDMCC 1.3076T=JCM 35610T), respectively.

Mangrovimonas aestuarii sp. nov., isolated from tidal flat sediment.

A Gram-stain-negative, rod-shaped and light yellow-pigmented strain designated MBT5T was isolated from tidal flat sediment of an oyster farming area in Quanzhou Bay, PR China. Catalase activity and oxidase activity were positive. Flexirubin-type pigment was absent. Growth was observed at 10-40 °C (optimum, 35 °C), pH 6-9 (optimum, pH 7), and with 1-7 % NaCl (optimum, 2 %, w/v). The 16S rRNA gene of strain MBT5T had maximum sequence similarity values with Meridianimaribacter flavus NH57NT, Mangrovimonas yunxiaonensis LYYY01T and Mangrovimonas futianensis AS18T of 95.6, 95.4 and 94.9 %, respectively. Phylogenetic analysis based on 16S rRNA gene sequences and 120 conserved concatenated proteins indicated that strain MBT5T was affiliated to the genus Mangrovimonas and formed a distinct monophyletic branch. The digital DNA-DNA hybridization, average nucleotide identity and average amino acid identity values between strain MBT5T and the type strains of Mangrovimonas were estimated to be 17.3-18.7 %, 70.9-71.5 % and 66.4-68.2 %, respectively. The respiratory quinone was menaquinone-6. The major fatty acids were iso-C15 : 0 and iso-C15 : 1 G. The draft genome size was 2 952 053 bp with a DNA G+C content of 36.5 %. Based on phenotypic, physiological, phylogenetic and genomic data, together with chemotaxonomic characteristics, strain MBT5T represents a novel species, for which the name Mangrovimonas aestuarii sp. nov. is proposed. The type strain is MBT5T (=MCCC 1K06186T=KCTC 92888T=GDMCC 1.3851T).

Description of Flavobacterium agricola sp. nov., an auxin producing bacterium isolated from paddy field.

An auxin-producing bacterial strain, CC-SYL302T, was isolated from paddy soil in Taiwan and identified using a polyphasic taxonomic approach. The cells were observed to be aerobic, non-motile, non-spore-forming rods, and tested positive for catalase and oxidase. Produced carotenoid but flexirubin-type pigments were absent. Optimal growth of strain CC-SYL302T was observed at 25 °C, pH 7.0, and with 2% (w/v) NaCl present. Based on analysis of 16S rRNA gene sequences, it was determined that strain CC-SYL302T belongs to the genus Flavobacterium of the Flavobacteriaceae family. The closest known relatives of this strain are F. tangerinum YIM 102701-2 T (with 93.3% similarity) and F. cucumis R2A45-3 T (with 93.1% similarity). Digital DNA-DNA hybridization (dDDH) values were calculated to assess the genetic distance between strain CC-SYL302T and its closest relatives, with mean values of 21.3% for F. tangerinum and 20.4% for F. cucumis. Strain CC-SYL302T exhibited the highest orthologous average nucleotide identity (OrthoANI) values with members of the Flavobacterium genus, ranging from 67.2 to 72.1% (n = 22). The dominating cellular fatty acids (> 5%) included iso-C14:0, iso-C15:0, iso-C16:0, iso-C15:0 3-OH, iso-C17:0 3-OH, C16:1 ω6c/C16:1 ω7c and C16:0 10-methyl/iso-C17:1 ω9c. The polar lipid profile consisted of phosphatidylethanolamine, an unidentified aminolipid, an unidentified aminophospholipid, and nine unidentified polar lipids. The genome (2.7 Mb) contained 33.6% GC content, and the major polyamines were putrescine and sym-homospermidine. Strain CC-SYL302T exhibits distinct phylogenetic, phenotypic, and chemotaxonomic characteristics, as well as unique results in comparative analysis of 16S rRNA gene sequence, OrthoANI, dDDH, and phylogenomic placement. Therefore, it is proposed that this strain represents a new species of the Flavobacterium genus, for which the name Flavobacterium agricola sp. nov. is proposed. The type strain is CC-SYL302T (= BCRC 81320 T = JCM 34764 T).

Arthrobacter vasquezii sp. nov., isolated from a soil sample from Union Glacier, Antarctica.

A Gram-stain-positive, catalase-positive, non-motile bacteria, with a rod-coccus cycle (designated as EH-1B-1T) was isolated from a soil sample from Union Glacier in Ellsworth Mountains, Antarctica. Strain EH-1B-1T had an optimal growth temperature of 28 °C and grew at pH 7-10. The major cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0, C16 : 0 and anteiso-C17 : 0. The G+C content based on the whole genome sequence was 63.1 mol%. Strain EH-1B-1T was most closely related to members of the genus Arthrobacter, namely Arthrobacter subterraneus and Arthrobacter tumbae. The strain grew on tryptic soy agar, Reasoner's 2A agar, lysogeny broth agar and nutrient agar. The average nucleotide identity and digital DNA-DNA hybridization values between strain EH-1B-1T and its closest reference type strains ranged from 78 to 88 % and from 20.9 to 36.3 %, respectively. Based on phenotypic, chemotypic and genotypic evidence, it is proposed that strain EH-1B-1T represents a novel species of Arthrobacter, for which the name Arthrobacter vasquezii sp. nov. is proposed, with strain EH-1B-1T (RGM 3386T=LMG 32961T) as the type strain.

Pontibacter kalidii sp. nov., isolated from rhizosphere soil of Kalidium foliatum.

A Gram-negative, aerobic, gliding motile, rod-shaped bacterium, designated XAAS-72T, was isolated from the rhizosphere soil of Kalidium foliatum sampled in the Xinjiang Uyghur Autonomous Region, PR China. Cells grew at 4-45 °C, pH 5.0-8.0 and 0-8% NaCl, with optimal growth at 20-30 °C, pH 6.0-7.0 and 1-2 % NaCl. Strain XAAS-72T is closely related to members of the genus Pontibacter, namely Pontibacter korlensis CCTCC AB 206081T (97.6%) and Pontibacter flavimaris ACCC 19859T (97.2 %), and <94.6 % related to other currently described Pontibacter strains. The average nucleotide identity values between XAAS-72T and P. korlensis CCTCC AB 206081T and P. flavimaris ACCC 19859T were 77.9 and 86.9 %, respectively; the corresponding digital DNA-DNA hybridization values were 21.7 and 31.8 %. Menaquinone-7 was the predominant respiratory menaquinone. The polar lipids consisted of phosphatidylethanolamine, two unidentified aminophospholipids, two unidentified glycolipids and five unidentified lipids. The major cellular fatty acids were summed feature 4 (containing iso-C17 : 1 I/anteiso-C17 : 1 B), summed feature 3 (containing C16 : 1 ω7c/C16 : 1 ω6c) and iso-C15 : 0. The genome length of strain XAAS-72T was 5 054 860 bp with a genomic DNA G+C content of 54.5 mol%. The phenotypic and genotypic data suggest that strain XAAS-72T represents a novel species of the genus Pontibacter, for which the name Pontibacter kalidii sp. nov. is proposed. The strain is XAAS-72T (CGMCC 16594T=KCTC 72095T).

Gracilibacillus salinarum sp. nov. and Gracilibacillus caseinilyticus sp. nov., halotolerant bacteria isolated from a saltern environment.

Two aerobic, Gram-stain-positive, spore-forming motile bacterial strains, designated SSPM10-3T and SSWR10-1T, were isolated from salterns in Jeollanam province of South Korea. Both strains were halotolerant and grew well in 5 % NaCl but not in 20 and 25% NaCl, respectively. Optimal growth was observed with 5 % NaCl, at 30 °C and at pH 7.0-8.0. On the basis of the results of phylogenetic analysis using 16S rRNA gene sequence, both the strains were placed within the genus Gracilibacillus with Gracilibacillus massiliensis (98.65 % similarity) as their nearest neighbour. Menaquinone-7 (MK-7) (97 %) was the major isoprenoid quinone in both strains and major cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0 and anteiso-C17 : 0. Orthologous average nucleotide identity with usearch (OrthoANIu) and digital DNA-DNA hybridisation (dDDH) percentage comparison indicated that SSPM10-3T and SSWR10-1T exhibited highest similarity with G. massiliensis Awa-1T at 74.27 % and 21.0 and 74.23 % and 20.0 %, respectively. The DNA G+C contents of the strains were 39.1 % (SSPM10-3T) and 38.5 % (SSWR10-1T). Members of the genus Gracilibacillus, both strains were distinct from each other with respect to their ability to produce urease, ß-glucosidase, assimilation of inulin and methyl-α-d-glucopyranoside and degradation of casein. Compared with each other, ANI and d4 dDDH calculations were only 88.2 % and 36.3 %, well below the cut-off values for species delineation for each index. On the basis of their phenotypic, physiological, biochemical and phylogenetic characteristics,SSPM10-3T and SSWR10-1T represent distinct novel species for which names Gracilibacillus salinarum SSPM10-3T and Gracilibacillus caseinilyticus SSWR10-1T are proposed. The type strains are SSPM10-3T (=KACC 21933T =NBRC 115502T) and SSWR10-1T (=KACC 21934T =NBRC 115503T).

Brumimicrobium oceani sp. nov., isolated from coastal sediment saline lake and environmental adaptability analysis.

A novel Gram-stain-negative, aerobic, non-motile, rod-shaped and orange-colored bacterium, designated as strain C305T, was isolated from marine sediment of the coast area of Weihai, China. Strain C305T growth occurs at 4-40 °C (optimally at 30-33 °C), pH 6.0-9.0 (optimally at pH 8.0) and with 0.5-10.0% (w/v) NaCl (optimum 1.5-3.0%). No growth is observed without NaCl. The major cellular fatty acids of strain C305T were identified as iso-C15:0, iso-C15:1G and iso-C17:0 3-OH. The major respiratory quinone was found to be MK-6, and the DNA G + C content was determined to be 35.5 mol%. The predominant polar lipids were mainly phosphatidylethanolamines (PE), unidentified aminophospholipids (APL), andunidentified lipid (L2). Phylogenetic analysis based on 16S rRNA gene sequences revealed that C305T was a member of the genus Brumimicrobium and had a 16S rRNA gene sequence similarity values of 96.9-98.0% with recognized Brumimicrobium species. On the basis of the phylogenetic and phenotypic evidences, strain C305T represents a novel species of the genus Brumimicrobium, for which the name Brumimicrobium oceani sp. nov. is proposed. The type strain is C305T (= KCTC 62371 T = MCCC 1H00297T).

Psychroserpens ponticola sp. nov. and Marinomonas maritima sp. nov., isolated from seawater.

Two Gram-stain-negative, catalase- and oxidase-positive, aerobic non-motile and motile rod bacteria, strains MSW6T and RSW2T, were isolated from surface seawater. Strain MSW6T optimally grew at 20 °C, pH 7.0 and 3 % NaCl, while strain RSW2T optimally grew at 25 °C, pH 7.0-8.0 and 2 % NaCl. Strain MSW6T possessed menaquinone-6 as the major respiratory quinone, and its major fatty acids were iso-C15 : 1 G, iso-C15 : 0 and iso-C15 : 0 3-OH. The major polar lipid identified in strain MSW6T was phosphatidylethanolamine (PE). On the other hand, strain RSW2T had ubiquinone-8 as the predominant respiratory quinone, and its major fatty acids consisted of summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c) and C16 : 0. The major polar lipids identified in strain RSW2T were PE and phosphatidylglycerol. As the sole respiratory quinone, strain MSW6T possessed menaquinone-6, while strain RSW2T had ubiquinone-8. The DNA G+C contents of strains MSW6T and RSW2T were 31.9 and 43.4 mol%, respectively. Phylogenetic analyses based on 16S rRNA and core gene sequences showed that strain MSW6T formed a phylogenic lineage with Psychroserpens mesophilus KOPRI 13649T, while strain RSW2T formed a phylogenic lineage with Marinomonas primoryensis KMM 3633T. Strain MSW6T shared 97.9 % 16S rRNA gene sequence similarity and 80.7 % average nucleotide identity (ANI) ith P. mesophilus KOPRI 13649T, and strain RSW2T shared 99.1 % 16S rRNA gene sequence similarity and 93.1 % ANI with M. primoryensis KMM 3633T. Based on the results of phenotypic, chemotaxonomic and phylogenetic analyses, strains MSW6T and RSW2T represent novel species of the genera Psychroserpens and Marinomonas, respectively, for which the names Psychroserpens ponticola sp. nov. and Marinomonas maritima sp. nov. are proposed, respectively. The type strain of P. ponticola is MSW6T (=KACC 22338T=JCM 35022T) and the type strain of M. maritima is RSW2T (=KACC 22716T=JCM 35550T).