Chelativorans salis sp. nov., a slightly halophilic bacterium isolated from an enrichment system with saline lake sediment.

A Gram-stain-negative, non-motile, and slightly halophilic alphaproteobacterium, designated strain EGI FJ00035T, was isolated from enrichment sediment samples of a saline lake in Xinjiang Uygur Autonomous Region, PR China. The taxonomic position of the isolate was determined using the polyphasic taxonomic and phylogenomic analyses. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain EGI FJ00035T formed a distinct clade with 'Chelativorans alearense' UJN715 and 'Chelativorans xinjiangense' lm93 with sequence similarities of 98.44 and 98.22 %, respectively, while sharing less than 96.7 % with other valid type strains. The novel isolate could be distinguished from other species of the genus Chelativorans by its distinct phenotypic, physiological, and genotypic characteristics. Optimal growth of strain EGI FJ00035T occurred on marine agar 2216 at pH 7.0 and 30 °C. The major respiratory quinone was Q-10, while the major fatty acids (>5 %) were C19 : 0 cyclo ω8c, summed feature 8 (C17 : 1 ω6c and/or C17 : 1 ω7c), C16 : 0, C18 : 0, and iso-C17 : 0. The detected polar lipids included diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, unidentified aminophospholipids, unidentified glycolipids, and an unidentified lipid. Based on its genome sequence, the G+C content of strain EGI FJ00035T was 63.2 mol%. The average nucleotide identity, average amino acid identity, and digital DNA-DNA hybridization values of strain EGI FJ00035T against related members of the genus Chelativorans were below the thresholds for delineation of a novel species. According our polyphasic taxonomic data, strain EGI FJ00035T represents a new species of the genus Chelativorans, for which the name Chelativorans salis sp. nov. is proposed. The type strain of the proposed novel isolate is EGI FJ00035T (=KCTC 92251T=CGMCC 1.19480T).

Sphingomicrobium clamense sp. nov., Isolated from Sediment of Clam Island Beach in China.

A Gram-stain-negative, non-flagellated, aerobic, ovoid or rod-shaped bacterium with motility, designated B8T, was isolated from the sediment of Clam Island beach, Liaoning province, China. The optimum growth of strain B8T occurred at 35 oC, pH 7.0, and in the presence of 4.0-5.0% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain B8T formed a distinct lineage within the genus Sphingomicrobium and was closely related to Sphingomicrobium nitratireducens O-35T (98.3% sequence similarity), Sphingomicrobium aestuariivivum KCTC 42286T (96.9%), and Sphingomicrobium astaxanthinifaciens JCM 18551T (96.5%). The digital DNA-DNA hybridization and average nucleotide identity values between strain B8T and closely related strains were lower than 21.0% and 78.0%, much lower than the cutoff values of 70.0% and 95.0%, respectively, for bacterial species delineation. The dominant respiratory quinone of strain B8T was ubiquinone-10. The major fatty acids were Sum In Feature 8 (C18:1ω7c and/or C18:1ω6c), Sum In Feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C17:1ω6c, C18:1 2-OH, and C16:0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, glycolipids, and four unknown polar lipids. The DNA G + C content of strain B8T was 63.9%. Based on the phenotypic, phylogenetic, and chemotaxonomic analyses, strain B8T is considered a new species of Sphingomicrobium, for which the name Sphingomicrobium clamense sp. nov. is proposed. The type strain is B8T (= CGMCC 1.19486T = KCTC 92052T).

Azospirillum isscasi sp. nov., a bacterium isolated from rhizosphere soil of rice.

A Gram-negative and rod-shaped bacterium, designated C340-1T, was isolated and screened from paddy soil in Zhongshan County, Guangxi Province, PR China. This strain grew at 20-42 °C (optimum, 37 °C), pH 5.0-9.0 (optimum, pH 7.0) and 0-4 % (w/v) NaCl (optimum, 0-1 %) on Reasoner's 2A medium. The strain could fix atmospheric nitrogen and acetylene reduction activity was recorded up to 120.26 nmol ethylene h-1 (mg protein)-1. Q-10 was the only isoprenoid quinone component; phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, an unidentified aminolipid and an unidentified polar lipid were the major polar lipids. Summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c) and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) were the primary cellular fatty acids. The genome of strain C340-1T was 6.18 Mb, and the G+C content was 69.0 mol%. Phylogenetic tree analysis based on 16S rRNA gene and 92 core genes showed that strain C340-1T was closely related to and clustered with the type strains Azospirillum brasilense JCM 1224T, Azospirillum argentinense Az39T, Azospirillum baldaniorum Sp245T and Azospirillum formosense JCM 17639T. The average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH) values between strain C340-1T and the closely related type strains mentioned above were significantly lower than the threshold values for species classification (95-96 %, 95-96 % and 70 %, respectively). Based on phylogenetic, genomic, phenotypic, physiological and biochemical data, we have reason to believe that C340-1T represents a new species of the genus Azospirillum, for which the name Azospirillum isscasi sp. nov. is proposed. The type strain is C340-1T(=CCTCC AB 2023105T=KCTC 8126T).

Effects of arginine on coenzyme-Q10 micelle uptake for mitochondria-targeted nanotherapy in phenylketonuria.

Phenylketonuria (PKU) is a rare inherited metabolic disease characterized by phenylalanine hydroxylase enzyme deficiency. In PKU patients, coenzyme Q10 (CoQ10) levels were found low. Therefore, we focused on the modification of CoQ10 to load the micelles and increase entry of micelles into the cell and mitochondria, and it is taking a part in ATP turnover. Micelles had produced by comparing two different production methods (thin-film layer and direct-dissolution), and characterization studies were performed (zeta potential, size, and encapsulation efficiency). Then, L-arginine (LARG) and poly-arginine (PARG) were incorporated with the micelles for subsequential release and PKU cell studies. The effects of these components on intracellular uptake and their use in the cellular cycle were analyzed by ELISA, Western blot, membrane potential measurement, and flow cytometry methods. In addition, both effects of LARG and PARG micelles on pharmacokinetics at the cellular level and their cell binding rate were determined. The thin-film method was found superior in micelle preparation. PARG/LARG-modified micelles showed sustained release. In the cellular and mitochondrial uptake of CoQ10, CoQ10-micelle + PARG > CoQ10-micelle + LARG > CoQ10-micelle > CoQ10 was found. This increased localization caused lowering of oxygen consumption rates, but maintaining mitochondrial membrane potential. The study results had showed that besides micelle formulation, PARG and LARG are effective in cellular and mitochondrial targeting.

Tianweitania aestuarii sp. nov., isolated from a coastal dune, reclassification of Corticibacterium populi as Tianweitania populi comb. nov., and emended description of the genus Tianweitania.

A Gram-stain-negative, aerobic, non-flagellated and coccoid or ovoid bacterial strain, BSSL-BM11T, was isolated from sand of coastal dunes along the Yellow Sea of the Korean peninsula. Strain BSSL-BM11T grew optimally at 30 °C, at pH 7.0-8.0 and in the presence of 2.0-3.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences, the up-to-date bacterial core gene set and average amino acid identity (AAI) showed that strain BSSL-BM11T forms a cluster with the type strains of Tianweitania sediminis and Corticibacterium populi. Strain BSSL-BM11T showed 16S rRNA gene sequence similarities of 98.3 and 98.0 % to the type strains of T. sediminis and C. populi, respectively, and less than 96.4 % to the type strains of the other recognized species. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain BSSL-BM11T and the type strains of T. sediminis and C. populi were 77.0-84.8 % and 20.0-28.1 %, respectively. The 16S rRNA gene similarity, AAI, ANI and dDDH values between T. sediminis Z8T and C. populi KCTC 42249T were 98.0, 77.4, 76.7 and 20.1 %, respectively. The DNA G+C content of strain BSSL-BM11T from genomic sequence data was 61.3 mol%. Strain BSSL-BM11T contained Q-10 as the predominant ubiquinone and C18 : 1 ω7c, C16 : 0 and cyclo C19 : 0 ω8c as the major fatty acids. The major polar lipids of strain BSSL-BM11T were phosphatidylcholine, phosphatidylglycerol and phosphatidylethanolamine. Based on the polyphasic data, it is proposed that C, populi be reclassified as a member of the genus Tianweitania. Phenotypic and phylogenetic analyses revealed that strain BSSL-BM11T is separated from T. sediminis and C. populi. On the basis of the data presented here, strain BSSL-BM11T (=KACC 21634T=NBRC 114503T) is considered to represent a novel species of the genus Tianweitania, for which the name Tianweitania aestuarii sp. nov. is proposed.

Marinomonas transparens sp. nov. and Marinomonas sargassi sp. nov., isolated from marine alga.

Two Gram-stain-negative, rod-shaped, non-spore-forming, strictly aerobic, motile bacteria with a single polar flagellum, designated strains C1424T and C2222T, were isolated from marine alga collected from the sea shore at Yantai, PR China. Strain C1424T grew at 4-37 °C and in the presence of 1-9 % (w/v) NaCl, while strain C2222T grew at 4-32 °C with 1-6 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences and concatenated amino acid sequences of 120 ubiquitous single-copy proteins showed that both strains C1424T and C2222T belonged to the genus Marinomonas, showing highest 16S rRNA gene sequence similarities to the type strains of Marinomonas primoryensis (98.1 %) and Marinomonas dokdonensis (98.1 %), respectively. The major fatty acids of the two strains were C18 : 1 ω6c and/or C18 : 1 ω7c, C16 : 1 ω6c and/or C16 : 1 ω7c and C16 : 0, their predominant polar lipids were phosphatidylethanolamine and phosphatidylglycerol, and their sole respiratory quinone was Q8. On the basis of polyphasic analyses, strains C1424T and C2222T are considered to represent two novel species within the genus Marinomonas, for which the names Marinomonas transparens sp. nov. and Marinomonas sargassi sp. nov. are proposed. The type strains are C1424T (=KCTC 72119T=MCCC 1K03601T) and C2222T (=KCTC 72120T=MCCC 1K03602T), respectively.

Pacificoceanicola onchidii gen. nov., sp. nov., isolated from a marine invertebrate from the South China Sea.

A Gram-stain-negative, facultative anaerobic, non-flagellated and oval-shaped (0.77-0.98 µm wide and 0.74-1.21 µm long) bacterial strain, designated XY-301T, was isolated from a marine invertebrate collected from the South China Sea. Strain XY-301T grew at 15-37 °C (optimum, 30-35 °C) and at pH 7.0-8.5 (optimum, pH 8.0). The strain was slightly halophilic and it only grew in the presence of 0.5-6.5 % (w/v) NaCl (optimum, 2.5-3.5 %). Its predominant fatty acid (>10 %) was C18 : 1 ω7c. The predominant polar lipids of XY-301T were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, six unidentified aminolipids, three unidentified phospholipids and two unknown polar lipids. The respiratory quinone was Q-10. The genome of XY-301T was 4 979 779 bp in size, with a DNA G+C content of 61.3 mol%. The average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values between XY-301T and Pseudoprimorskyibacter insulae SSK3-2T were 73.3, 14.5 and 53.5 %, respectively. Based on the results of phylogenetic, phenotypic, chemotaxonomic and genomic analyses, strain XY-301T is considered to represent a novel species and a new genus of the family Roseobacteraceae, for which the name Pacificoceanicola onchidii gen. nov., sp. nov. is proposed. The type strain is XY-301T (=KCTC 72212T=MCCC 1K03614T).

Hoeflea poritis sp. nov., isolated from a bleached scleractinian coral Porites lutea.

A Gram-stain-negative, aerobic, rod-shaped, nonmotile and yellow-pigmented bacterium designated E7-10T was isolated from a bleached scleractinian coral Porites lutea. Strain E7-10T grew with 1.0-8.0 % (w/v) NaCl (optimum, 4.0 %), at 18-41 °C (optimum, 28 °C) and at pH 6.0-10.0 (optimum, pH 8.0). Phylogenetic analysis using 16S rRNA gene sequences revealed that E7-10T formed a lineage within the genus Hoeflea, but it was distinct from the closest species 'Hoeflea prorocentri' PM5-8T, showing 98.01 % sequence similarity. The predominant cellular fatty acids of E7-10T were summed feature 8 (26.7 %), C18 : 1 ω7c 11-methyl (26.2 %), C16 : 0 (20.8 %) and C19 : 0 cyclo ω8c (17.9 %). The major respiratory quinone was Q-10. The polar lipids mainly comprised phosphatidylethanolamine, two glycolipids and five phospholipids. The genome size of E7-10T was 5.58 Mb with G+C content 60.27 mol%. The digital DNA-DNA hybridization and average nucleotide identity values between the genomes of strains E7-10T and PM5-8T were 19.50 and 75.95 %, respectively, which were both below the defined cutoff values (70 % and 95-96 %, respectively) for species delimitation. Thus, strain E7-10T represents a novel species within the genus Hoeflea, for which the name Hoeflea poritis sp. nov. is proposed. The type strain is E7-10T (=JCM 35852T=MCCC 1K08229T).

Aurantibacillus circumpalustris gen. nov., sp. nov., the first characterized representative of the Bacteroidota candidate family env.OPS 17 and proposal of Aurantibacillaceae fam. nov.

16S rRNA sequence types associated with the candidate family env.OPS 17 have been reported from various environments, but no representatives have been characterized and validly named. Bacteria of env.OPS 17 are affiliated with the order Sphingobacteriales and were first detected more than two decades ago in the vicinity of a thermal spring in Yellowstone National Park. Strain Swamp196T, isolated from the soil surrounding a swamp in Northern Germany, is the first characterized representative of candidate family env.OPS 17. Cells of strain Swamp196T are rod-shaped, non-motile, non-spore-forming, non-capsulated and stain Gram-negative. Colonies are small and orange-coloured. The strain is mesophilic and grows under aerobic or microaerophilic conditions. It grows chemo-organotrophically over a narrow range of pH and exclusively on proteinaceous substrates. The major cellular fatty acids are iso-C15 : 0, iso-C15 : 1 ω10c, C18 : 1 ω9c and C16 : 1 ω7c and the major polar lipids are two unidentified aminophospholipids, one unidentified aminolipid and one unidentified lipid. The predominant respiratory quinone is MK-7. The DNA G+C content of genomic DNA is 35.5 mol%. Strain Swamp196T is related to Pedobacter cryophilus AR-3-17T, Arcticibacter pallidicorallinus Hh36T and Pedobacter daechungensis Dae 13T with 16S rRNA gene sequence similarity of 84.1, 83.8 and 83.5 %, respectively. Based on our phenotypic, genomic and phylogenetic analysis, we propose the novel species Aurantibacillus circumpalustris sp. nov (type strain Swamp196T=DSM 105849T=CECT 30420T) of the novel genus Aurantibacillus gen. nov. and the novel family Aurantibacillaceae fam. nov.

Bioplastic (poly-3-hydroxybutyrate)-producing Massilia endophytica sp. nov., isolated from Cannabis sativa L. 'Cheungsam'.

A rod-shaped, motile, Gram-negative bacterial strain named DM-R-R2A-13T was isolated from the plant Cannabis sativa L. 'Cheungsam'. The phylogenetic analysis of the 16S rRNA gene sequence revealed that strain DM-R-R2A-13T belongs to the family Oxalobacteraceae and is closely related to members of the genus Massilia, with Massilia flava (97.58% sequence similarity) and Massilia armeniaca (97.37% sequence similarity) being the closest members. The digital DNA-DNA hybridization (dDDH) values between strain DM-R-R2A-13T and Massilia flava CGMCC 1.10685T and Massilia armeniaca ZMN-3Twere 22.2% and 23.3%, while the average nucleotide identity (ANI) values were 78.85% and 79.63%, respectively. The DNA G+C content was measured to be 64.6 mol%. Moreover, the bacterium was found to contain polyhydroxyalkanoate (PHA) granules based on transmission electron microscopy, indicating its potential to produce bioplastic. Genome annotation revealed the presence of PHA synthase genes (phaC, phaR, phaP, and phaZ), and the biopolymer was identified as poly-3-hydroxybutyrate (PHB) based on nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR) analyses. Using maltose as a carbon source, the strain produced PHB of up to 58.06% of its dry cell weight. Based on the phenotypic, chemotaxonomic, and phylogenetic characteristics, it has been determined that DM-R-R2A-13T represents a novel species belonging to the genus Massilia. As such, the name Massilia endophytica sp. nov. is proposed for this newly identified species. The type strain is DM-R-R2A-13T (= KCTC 92072T = GDMCC 1.2920T).

Halocynthiibacter halioticoli sp. nov., isolated from the viscera of abalone Haliotis discus hannai.

A Gram-stain-negative, rod-shaped, glide, non-flagellated, and facultatively anaerobic bacterial strain, designated as Z654T, was isolated from the gut of abalone Haliotis discus hannai from Rongcheng, Shandong province, China. Cells are 0.2-0.8 µm in width and 0.7-3.4 µm in length. Cells grew best at 30 °C (range, 15-37 °C), pH 7.0 (range, 6.0-8.5) and NaCl concentration of 2.0% (w/v) (range, 1-10%). According to the phylogenetic analysis of 16S rRNA gene sequence, the strain belongs to the genus Halocynthiibacter and the closest strain is Halocynthiibacter arcticus KCTC 42129 T (97.12%). The genome size of strain Z654T was 3,296,250 bp and the DNA G + C content was 54.2 mol%. The average nucleotide identity (ANI) scores and digital DNA-DNA hybridization (dDDH) scores with H. arcticus KCTC 42129 T were 70% and 14.6-18.2%, respectively. The predominant quinone was Q-10 and the major fatty acids were C18:0, C18:1 ω7c 11-methyl and summed feature 8. The polar lipids consisted of phosphatidylcholine, phosphatidylglycerol, unidentified aminolipid and unidentifed lipids. Based on the phenotypic, phylogenetic and chemotaxonomic data, strain Z654T was considered to represent a novel species of the genus Halocynthiibacter, for which the name Halocynthiibacte halioticoli sp. nov., is proposed. The type strain is Z654T (= MCCC 1H00503T = KCTC 92003 T).

Shumkonia mesophila gen. nov., sp. nov., a novel representative of Shumkoniaceae fam. nov. and its potentials for extracellular polymeric substances formation and sulfur metabolism revealed by genomic analysis.

A microaerophilic, mesophilic, chemoorganoheterotrophic bacterium, designated Y-P2T, was isolated from oil sludge enrichment in China. Cells of the strain were Gram-stain-negative, non-motile, non-spore-forming, rod-shaped or slightly curved with 0.8-3.0 µm in length and 0.4-0.6 µm in diameter. The strain Y-P2T grew optimally at 25 °C (range from 15 to 30 °C) and pH 7.0 (range from pH 6.0 to 7.5) without NaCl. The major cellular fatty acids were C16:0, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). The main polar liquids of strain Y-P2T comprised phosphatidylethanolamine (PE) and phosphatidylglycerol (PG). The respiratory quinone was Q-10. Acetate and H2 were the fermentation products of glucose. The DNA G + C content was 66.0%. Strain Y-P2T shared the highest 16S rRNA gene sequence similarity (90.3-90.6%) with species within Oceanibaculum of family Thalassobaculaceae in Rhodospirillales. Phylogenetic analyses based on 16S rRNA gene sequences and genomes showed that strain Y-P2T formed a distinct evolutionary lineage within the order Rhodospirillales. On the basis of phenotypic, phylogenetic and phylogenomic data, we propose that strain Y-P2T represents a novel species in a novel genus, for which Shumkonia mesophila gen. nov., sp. nov., within a new family Shumkoniaceae fam. nov. The type strain is Y-P2T (= CCAM 826 T = JCM 34766 T).

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).

Tropicibacter oceani sp. nov., a novel sulfur-metabolizing bacteria isolated from the intertidal zone sediment of Chinese Yellow Sea.

In this study, we reported a Gram-stain-negative, rod-shaped, atrichous, and aerobic bacterial strain named YMD87T, which was isolated from the intertidal zone sediment of Chinese Yellow Sea. Growth of strain YMD87T occurred at 10.0-40.0 °C (optimum, 25-30 °C), pH 4.0-12.0 (optimum, 8.0) and with 0-6.0% (w/v) NaCl (optimum, 0.0-2.0%). Phylogenetic tree analysis based on 16S rRNA gene sequence indicated that strain YMD87T belonged to the genus Tropicibacter and was closely related to Tropicibacter alexandrii LMIT003T (97.2% sequence similarity). Genomic analysis indicated that strain YMD87T contains a circular chromosome of 3,932,460 bp with G + C content of 63.8% and three circular plasmids of 116,492 bp, 49,209 bp and 49,673 bp, with G + C content of 64.3%. Genomic functional analysis revealed that strain YMD87T is potential a novel sulfur-metabolizing bacteria. The predominant respiratory quinone of YMD87T was ubiquinone-10 (Q-10). The major polar lipids of YMD87T contained phosphatidylglycerol, phosphatidylethanolamine, five unidentified lipids, five unidentified phospholipids, phosphatidylcholine, unidentified glycolipid and five unidentified aminolipids. The major fatty acids of strain YMD87T contained C12:1 3-OH, C16:0, and summed feature 8 (C18:1 ω7c or/and C18:1 ω6c). Phylogenetic, physiological, biochemical and morphological analyses suggested that strain YMD87T represents a novel species of the genus Tropicibacter, and the name Tropicibacter oceani sp. nov is proposed. The type strain is YMD87T (= MCCC 1K08473T = KCTC 92856 T).

Parasedimentitalea psychrophila sp. nov., a psychrophilic bacterium isolated from deep-sea sediment.

A novel bacterium, strain QS115T, was isolated from deep-sea sediment collected from the South China Sea at a depth of 1151 m. Phylogenetic analyses based on 16S rRNA gene sequences indicated that QS115T was most closely related to Parasedimentitalea marina W43T, with similarity of 98.21 %. Strain QS115T shared 82.39 % average nucleotide identity, 26.3 % digital DNA-DNA hybridization and 85.32 % average amino acid identity with P. marina W43T. Cells of strain QS115T were Gram-stain-negative, rod-shaped and grew optimally at 10 °C, pH 7.5 and 2 % (w/v) NaCl. The principal fatty acids were summed feature 8 (C18 : 1 ω7c/ω6c), the major respiratory quinone was ubiquinone-10 and predominant polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, glycophospholipid, phosphatidylglycerol and phosphatidylcholine. Polyphasic analyses of physiological and phenotypic characteristics and genomic studies suggested that strain QS115T represents a novel species of the genus Parasedimentitalea, for which the name Parasedimentitalea psychrophila sp. nov. is proposed (type strain QS115T=MCCC 1K04395T=JCM 34219T).

Lipid nanoparticles containing coenzyme Q10 for topical applications: An overview of their characterization.

The coenzyme Q10 is a compound widely used in pharmaceutical and cosmetic formulations because it is a potent eliminator of free radicals, giving it antioxidant and anti-aging properties. It is naturally synthesized by the human body, but its production wanes with age, leading to the formation of wrinkles. The efficacy of topical application of the coenzyme to counteract this process is subject to several difficulties, due to its instability in the presence of light, low solubility in water and high lipophilicity. Because of these drawbacks, many studies have been conducted of release systems. Lipid nanoparticles stand out in this sense due to the advantages of skin compatibility, protection of the active ingredient against degradation in the external medium, capacity to increase penetration of that ingredient in the skin, and its controlled and prolonged release. In this context, this article presents a review of the main studies of the coenzyme Q10 encapsulated in lipid nanoparticles for topical use, focusing on the analytic methods used to characterize the systems regarding morphology, zeta potential, release profile, Q10 content, encapsulation efficiency, crystalline organization and structure of the lipid matrix, rheology, antioxidant activity, skin penetration and efficacy, among other aspects. We also describe the main results of the different studies and discuss the critical aspects - the simplest, most reproducible, best, and most relevant - that characterize lipid nanoparticles with encapsulated Q10 for topical use.

Sinisalibacter aestuarii sp. nov., isolated from estuarine sediment of the Arakawa River.

A Gram-stain-negative, rod-shaped, non-motile and strictly aerobic bacterium, which showed biofilm-forming ability on polystyrene, designated as strain B-399T, was isolated from the estuarine sediment of the Arakawa River near Tokyo Bay. It grew at pH 6.0-8.5, at 15-35 °C and in the presence of 0-7.5 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain B-399T was clustered in the genus Sinisalibacter and has 96.94 % sequence similarity to Sinisalibacter lacisalsi X12M-4T, which was the only validly described species in this genus. On the basis of our genome sequencing analyses, the average nucleotide identity and digital DNA-DNA hybridization values between strains B-399T and S. lacisalsi X12M-4T were 79.54 and 22.30 %, respectively, which confirms that strain B-399T represents a novel species of the genus Sinisalibacter. The draft genome size and the DNA G+C content of strain B-399T were 4.12 Mb and 65.2 mol%, respectively. The major fatty acids (>10 %) of strain B-399T were C16 : 0, summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c) and C19 : 0 cyclo ω8c. The polar lipids were phosphatidylcholine, phosphatidylglycerol, an unidentified phospholipid, an unidentified aminolipid and unidentified lipids. The respiratory quinone was Q-10. These chemotaxonomic features were almost coincident with those of the genus Sinisalibacter. Therefore, strain B-399T should be classified as representing a new species of the genus Sinisalibacter, for which the name Sinisalibacter aestuarii sp. nov. is proposed. The type strain is B-399T (=NBRC 115629T=DSM 114148T).

Pantoea leporis sp. nov., isolated from the faecal material of a rabbit.

A facultative anaerobic, Gram-stain-negative rod-shaped bacterium, designated RT, was isolated from the faecal material of a rabbit (Sylvilagus floridanus). The strain could not be identified using an MALDI Biotyper sirius CA System. The closest matches based on the Bruker library were members of the genera Citrobacter and Pantoea. However, the score value was in the range of no organism identification possible. Based on pairwise of 16S rRNA gene sequence analysis, the isolate was found to be a member of the family Erwiniaceae. The highest sequence similarities were found to the sequences of Pantoea rodasii LMG 26273T (98.7 %), Leclercia adecarboxylata NBRC 102595T (98.5 %) and Enterobacter huaxiensis 090008T (98.4 %). Phylogenetic and whole genome analysis demonstrated that strain RT represents a novel species within the genus Pantoea. The predominant cellular fatty acids of strain RT were C16 : 0 and products present in summed feature 2 (C12 : 0) aldehyde, summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c) and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). In silico genome analysis showed the presence of enzymes required for production of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylserine. The G+C content determined from the genome was 54.94 mol %. Based on biochemical, phylogenetic, genotypic and chemotaxonomic criteria, the isolate represents a novel species of the genus Pantoea for which the name Pantoea leporis sp. nov. is proposed. The type strain is strain RT (=CCUG 76269T=ATCC TSD-291T).

Investigation of hydrated channels and proton pathways in a high-resolution cryo-EM structure of mammalian complex I.

Respiratory complex I, a key enzyme in mammalian metabolism, captures the energy released by reduction of ubiquinone by NADH to drive protons across the inner mitochondrial membrane, generating the proton-motive force for ATP synthesis. Despite remarkable advances in structural knowledge of this complicated membrane-bound enzyme, its mechanism of catalysis remains controversial. In particular, how ubiquinone reduction is coupled to proton pumping and the pathways and mechanisms of proton translocation are contested. We present a 2.4-Å resolution cryo-EM structure of complex I from mouse heart mitochondria in the closed, active (ready-to-go) resting state, with 2945 water molecules modeled. By analyzing the networks of charged and polar residues and water molecules present, we evaluate candidate pathways for proton transfer through the enzyme, for the chemical protons for ubiquinone reduction, and for the protons transported across the membrane. Last, we compare our data to the predictions of extant mechanistic models, and identify key questions to answer in future work to test them.

Ruegeria spongiae sp. nov., isolated from Callyspongia elongata.

A Gram-stain-negative, rod-shaped, polar flagellated, aerobic, light-yellow bacterium, designated as 2012CJ41-6T, was isolated from a sponge sample of Callyspongia elongata from Chuja-myeon, Jeju-si, Jeju-do, Republic of Korea. On the basis of 16S rRNA gene sequencing, strain 2012CJ41-6T clustered with species of the genus Ruegeria and appeared closely related to R. halocynthiae DSM 27839T (96.46 % similarity), R. denitrificans CECT 4357T (96.32 %), R. profundi ZGT108T (96.32 %), R. litorea CECT 7639T (96.32 %) and R. atlantica CECT 4292T (96.16 %). The average nucleotide identity and digital DNA-DNA hybridization between strain 2012CJ41-6T and the most closely related strain was 75.3 % and 19.6 %, indicating that 2012CJ41-6T represents a novel species of the genus Ruegeria. Growth occurred at 15-37 °C on marine medium in the presence of 0.5-10 % (w/v) NaCl and at pH 5.5-8.5. The DNA G+C content of the genomic DNA was 60.80 mol%, and ubiquinone-10 (Q-10) was the major respiratory quinone. The major cellular fatty acids (>5 %) were C18 : 1 ω7c and/or C18:1 ω6c (summed feature 8). The polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine, one unidentified phospholipid, one unidentified aminolipid, one unidentified aminophospholipid and five unidentified lipids. Physiological and biochemical characteristics indicated that strain 2012CJ41-6T represents a novel species of the genus Ruegeria, for which the name Ruegeria spongiae sp. nov. is proposed. The type strain is 2012CJ41-6T (=KACC 22645T=LMG 32585T).