Thioclava litoralis sp. nov., a novel species of alphaproteobacterium, isolated from surface seawater.

A Gram-negative, aerobic, rod-shaped, non-motile bacterium, designated as FTW29T, was isolated from surface seawater sampled in Futian district, Shenzhen, China. Growth of strain FTW29T was observed at 15-42 ℃ (optimum, 28-30 ℃), pH 4.0-9.0 (optimum, pH 5.5-7.5) and in the presence of 0.5-10% NaCl (optimum, 3.0% NaCl). Strain FTW29T showed 95.0-96.8% 16 S rRNA gene sequence similarity to various type strains of the genera Thioclava, Sinirhodobacter, Rhodobacter, Haematobacter and Frigidibacter of the family Paracoccaceae, and its most closely related strains were Thioclava pacifica DSM 10,166T (96.8%) and Thioclava marina 11.10-0-13T (96.7%). The phylogenomic tree constructed on the bac120 gene set showed that strain FTW29T formed a clade with the genus Thioclava, with a bootstrap value of 100%. The evolutionary distance values between FTW29T and type strains of the genus Thioclava were 0.17-0.19, which are below the recommended standard (0.21-0.23) for defining a novel genus in the family Paracoccaceae. In strain FTW29T, the major fatty acids identified were summed feature 8 (C18:1ω7c) and C16:0, and the predominant respiratory quinones were ubiquinone-10 and ubiquinone-9. The composition of polar lipids in strain FTW29T included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an unidentified phospholipid, an unidentified aminolipid, two unidentified glycolipids and an unidentified lipid. The genome of strain FTW29T comprised one circle chromosome and six plasmids, with a G + C content of 61.4%. The average nucleotide identity, average amino acid identity, and digital DNA-DNA hybridization values between strain FTW29T and seven type strains of the genus Thioclava were 76.6-78.4%, 53.2-56.4% and 19.3-20.4%, respectively. Altogether, the phenotypic, phylogenetic and chemotaxonomic evidence illustrated in this study suggested that strain FTW29T represents a novel species of the genus Thioclava, with the proposed name Thioclava litoralis sp. nov. The type strain is FTW29T (= KCTC 82,841T = MCCC 1K08523T).

Genome-based reclassification of Azospirillum brasilense Az39 as the type strain of Azospirillum argentinense sp. nov.

Strain Az39T of Azospirillum is a diazotrophic plant growth-promoting bacterium isolated in 1982 from the roots of wheat plants growing in Marcos Juárez, Córdoba, Argentina. It produces indole-3-acetic acid in the presence of l-tryptophan as a precursor, grows at 20-38 °C (optimal 38 °C), and the cells are curved or spiral-shaped, with diameters ranging from 0.5-0.9 to 1.8-2.2 µm. They contain C16 : 0, C18 : 0 and C18 : 1 ω7c/ω6c as the main fatty acids. Phylogenetic analysis of its 16S rRNA gene sequence confirmed that this strain belongs to the genus Azospirillum, showing a close relationship with Azospirillum baldaniorum Sp245T, Azospirillum brasilense Sp7T and Azospirillum formosense CC-Nfb-7T. Housekeeping gene analysis revealed that Az39T, together with five strains of the genus (Az19, REC3, BR 11975, MTCC4035 and MTCC4036), form a cluster apart from A. baldaniorum Sp245T, A. brasilense Sp7T and A. formosense CC-Nfb-7T. Average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) between Az39T and the aforementioned type strains revealed values below 96 %, the circumscription limit for the species delineation (ANI: 95.3, 94.1 and 94.0 %; dDDH: 62.9, 56.3 and 55.6 %). Furthermore, a phylogeny evaluation of the core proteome, including 809 common shared proteins, showed an independent grouping of Az39T, Az19, REC3, BR 11975, MTCC4035 and MTCC4036. The G+C content in the genomic DNA of these six strains varied from 68.3 to 68.5 %. Based on the combined phylogenetic, genomic and phenotypic characterization presented here, we consider that strain Az39T, along with strains Az19, REC3, BR 11975, MTCC4035 and MTCC4036, are members of a new Azospirillum species, for which the name Azospirillum argentinense sp. nov. is proposed. The type strain is Az39T (=LBPCV39T=BR 148428T=CCCT 22.01T).

A genomic overview including polyphasic taxonomy of Thalassoroseus pseudoceratinae gen. nov., sp. nov. isolated from a marine sponge, Pseudoceratina sp.

A pink-coloured, salt- and alkali-tolerant planctomycetal strain (JC658T) with oval to pear-shaped, motile, aerobic, Gram-negative stained cells was isolated from a marine sponge, Pseudoceratina sp. Strain JC658T shares the highest 16S rRNA gene sequence identity with Maioricimonas rarisocia Mal4T (< 89.2%) in the family Planctomycetaceae. The genomic analysis of the new strain indicates its biotechnological potential for the production of various industrially important enzymes, notably sulfatases and carbohydrate-active enzymes (CAZymes), and also potential antimicrobial compounds. Several genes encoding restriction-modification (RM) and CRISPR-CAS systems are also present. NaCl is obligate for growth, of which strain JC658T can tolerate a concentration up to 6% (w/v). Optimum pH and temperature for growth are 8.0 (range 7.0-9.0) and 25 ºC (range 10-40 °C), respectively. The major respiratory quinone of strain JC658T is MK6. Major fatty acids are C16:1ω7c/C16:1ω6c, C18:0 and C16:0. Major polar lipids are phosphatidylcholine, phosphatidyl-dimethylethanolamine and phosphatidyl-monomethylethanolamine. The genomic size of strain JC658T is 7.36 Mb with a DNA G + C content of 54.6 mol%. Based on phylogenetic, genomic (ANI, AAI, POCP, dDDH), chemotaxonomic, physiological and biochemical characteristics, we conclude that strain JC658T belongs to a novel genus and constitutes a novel species within the family Planctomycetaceae, for which we propose the name Thalassoroseus pseudoceratinae gen. nov., sp. nov. The novel species is represented by the type strain JC658T (= KCTC 72881 T = NBRC 114371 T).

Cellular Models for Primary CoQ Deficiency Pathogenesis Study.

Primary coenzyme Q10 (CoQ) deficiency includes a heterogeneous group of mitochondrial diseases characterized by low mitochondrial levels of CoQ due to decreased endogenous biosynthesis rate. These diseases respond to CoQ treatment mainly at the early stages of the disease. The advances in the next generation sequencing (NGS) as whole-exome sequencing (WES) and whole-genome sequencing (WGS) have increased the discoveries of mutations in either gene already described to participate in CoQ biosynthesis or new genes also involved in this pathway. However, these technologies usually provide many mutations in genes whose pathogenic effect must be validated. To functionally validate the impact of gene variations in the disease's onset and progression, different cell models are commonly used. We review here the use of yeast strains for functional complementation of human genes, dermal skin fibroblasts from patients as an excellent tool to demonstrate the biochemical and genetic mechanisms of these diseases and the development of human-induced pluripotent stem cells (hiPSCs) and iPSC-derived organoids for the study of the pathogenesis and treatment approaches.

Mitochondrial Coenzyme Q10 Determination Via Isotope Dilution Liquid Chromatography -Tandem Mass Spectrometry.

Coenzyme Q10 (CoQ10) is an essential part of the mitochondrial respiratory chain . Here, we describe an accurate and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method for determination of mitochondrial CoQ10 in isolated mitochondria . In the assay, mitochondrial suspensions are spiked with CoQ10-[2H9] internal standard (IS), extracted with organic solvents and CoQ10 quantified by LC-MS/MS using multiple reaction monitoring (MRM).

Hongsoonwoonella zoysiae gen. nov., sp. nov., a new member of the family Stappiaceae isolated from a tidal mudflat.

A Gram stain-negative bacterial strain, designated SY4-7T, was isolated from rhizosphere mudflat of a halophyte (Zoysia sinica) collected around Seonyu Island, Republic of Korea. Cells of the organism were strictly aerobic, non-sporulating, non-motile rods and grew at 20-42 °C, pH 6-8 and 1-6% (w/v) NaCl. The 16S rRNA gene-based phylogenetic analyses revealed that strain SY4-7T formed an independent cluster separated from the recognized genera of the family Stappiaceae, which was also supported by phylogenomic analysis-based 92-core gene sequences. The type stains of the phylogenetically closest relatives were Stappia indica (95.6% sequence similarity), Stappia stellulata (95.1%) and Roseibium hamelinense (95.1%). The isoprenoid quinone was Q-10. The polar lipids consisted of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, three unidentified aminophospholipids, an unidentified phosphoglycolipid, an unidentified aminolipid, two unidentified phospholipids and an unidentified lipid. The major cellular fatty acids are C18:1ω7c and C19:1 cyclo ω8c. The G + C content of the genomic DNA is 60.7%. Discrimination of the organism from all the recognized genera of the family Stappiaceae was apparent by the chemotaxonomic and phylogenetic features. Based on the results presented here, strain SY4-7T (= KCTC 72226T = NBRC 113902T) represents a novel species of a new genus in the family Stappiaceae, for which the name Hongsoonwoonella zoysiae sp. nov. is proposed.

Free radical imaging of endogenous redox molecules using dynamic nuclear polarization magnetic resonance imaging.

Redox reactions accompanied by the oxidation-reduction of endogenous molecules play important roles in maintaining homeostasis in living organisms. In humans, numerous endogenous molecules that contribute toward maintaining physiological conditions form free radicals via electron transfer. A typical example of this is the mitochondrial electron transport chain, which is involved in energy production. If free radicals derived from endogenous molecules could be visualized and exploited as biological and functional probes, redox reactions mediated by endogenous molecules could be detected non-invasively. We succeeded in visualizing the free radicals derived from endogenous molecules using an in vivo dynamic nuclear polarization (DNP) magnetic resonance imaging (MRI) system. In this review, we describe the visualization of endogenous redox molecules, such as flavins and ubiquinones, which are mitochondrial electron carriers, as well as vitamin E and vitamin C (ascorbate). In addition, we describe the application of melanin free radicals for the in vivo visualization of metabola without using probes via in vivo DNP-MRI.

Pseudomonas glycinae sp. nov. isolated from the soybean rhizosphere.

Strains MS586T and MS82, which are aerobic, Gram-negative, rod-shaped, and polar-flagellated bacteria, were isolated from the soybean rhizosphere in Mississippi. Taxonomic positions of MS586T and MS82 were determined using a polyphasic approach. 16S rRNA gene sequence analyses of the two strains showed high pairwise sequence similarities (>98%) to some Pseudomonas species. Analysis of the concatenated 16S rRNA, rpoB, rpoD, and gyrB gene sequences indicated that the strains belonging to the Pseudomonas koreensis subgroup (SG) shared the highest similarity with Pseudomonas kribbensis strain 46-2T . Analyses of average nucleotide identity (ANI), genome-to-genome distance, delineated MS586T and MS82 from other species within the genus Pseudomonas. The predominant quinone system of the strain was ubiquinone 9 (Q-9), and the DNA G+C content was 60.48 mol%. The major fatty acids were C16:0 , C17:0 cyclo, and the summed features 3 and 8 consisting of C16:1 ω7c/C16:1 ω6c and C18:1 ω7c/C18:1 ω6c, respectively. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, and diphosphatidylglycerol. Based on these data, it is proposed that strains MS586T and MS82 represent a novel species within the genus Pseudomonas. The proposed name for the new species is Pseudomonas glycinae, and the type strain is MS586T (accession NRRL B-65441 = accession LMG 30275).

Dietary Supplements for Male Infertility: A Critical Evaluation of Their Composition.

Dietary supplements (DS) represent a possible approach to improve sperm parameters and male fertility. A wide range of DS containing different nutrients is now available. Although many authors demonstrated benefits from some nutrients in the improvement of sperm parameters, their real effectiveness is still under debate. The aim of this study was to critically review the composition of DS using the Italian market as a sample. Active ingredients and their minimal effective daily dose (mED) on sperm parameters were identified through a literature search. Thereafter, we created a formula to classify the expected efficacy of each DS. Considering active ingredients, their concentration and the recommended daily dose, DS were scored into three classes of expected efficacy: higher, lower and none. Twenty-one DS were identified. Most of them had a large number of ingredients, frequently at doses below mED or with undemonstrated efficacy. Zinc was the most common ingredient of DS (70% of products), followed by selenium, arginine, coenzyme Q and folic acid. By applying our scoring system, 9.5% of DS fell in a higher class, 71.4% in a lower class and 19.1% in the class with no expected efficacy. DS marketed in Italy for male infertility frequently includes effective ingredients but also a large number of substances at insufficient doses or with no reported efficacy. Manufacturers and physicians should better consider the scientific evidence on effective ingredients and their doses before formulating and prescribing these products.

Introduction of the Menaquinone Biosynthetic Pathway into Rhodobacter sphaeroides and de Novo Synthesis of Menaquinone for Incorporation into Heterologously Expressed Integral Membrane Proteins.

Quinones are redox-active molecules that transport electrons and protons in organelles and cell membranes during respiration and photosynthesis. In addition to the fundamental importance of these processes in supporting life, there has been considerable interest in exploiting their mechanisms for diverse applications ranging from medical advances to innovative biotechnologies. Such applications include novel treatments to target pathogenic bacterial infections and fabricating biohybrid solar cells as an alternative renewable energy source. Ubiquinone (UQ) is the predominant charge-transfer mediator in both respiration and photosynthesis. Other quinones, such as menaquinone (MK), are additional or alternative redox mediators, for example in bacterial photosynthesis of species such as Thermochromatium tepidum and Chloroflexus aurantiacus. Rhodobacter sphaeroides has been used extensively to study electron transfer processes, and recently as a platform to produce integral membrane proteins from other species. To expand the diversity of redox mediators in R. sphaeroides, nine Escherichia coli genes encoding the synthesis of MK from chorismate and polyprenyl diphosphate were assembled into a synthetic operon in a newly designed expression plasmid. We show that the menFDHBCE, menI, menA, and ubiE genes are sufficient for MK synthesis when expressed in R. sphaeroides cells, on the basis of high performance liquid chromatography and mass spectrometry. The T. tepidum and C. aurantiacus photosynthetic reaction centers produced in R. sphaeroides were found to contain MK. We also measured in vitro charge recombination kinetics of the T. tepidum reaction center to demonstrate that the MK is redox-active and incorporated into the QA pocket of this heterologously expressed reaction center.

Coenzyme Q10 in association with metabolism-related AMPK/PFKFB3 and angiogenic VEGF/VEGFR2 genes in breast cancer patients.

Low levels of coenzyme Q10 (CoQ10) have been reported in the circulation of patients with breast cancer, particularly in metastatic features. Our objective was to study the correlation between plasma levels of CoQ10 and the tumoral expression levels of AMPK, PFKFB3, VEGF, and VEGFR2. This study was a part of consecutive case series conducted on 100 women with newly diagnosed invasive ductal breast carcinoma, with an age range of 30-60 years. Plasma levels of CoQ10 were measured using HPLC coupled to an UV detector. The expression levels were quantified using quantitative real-time PCR. Structural equation modeling (SEM) was applied to generate pathways describing gene-to-gene inter-correlations. Using SEM identified AMPK expression to contribute positively to VEGF-A/VEGFR2 ratio (coefficient b = 0.64, P < 0.001). The VEGFR2 expression positively correlated with tumor size (coefficient b = 0.31, P < 0.001). A linear correlation between expression levels of AMPK and PFKFB3 was observed (rAdj = - 0.273, P = 0.02). Similarly, VEGF-A was correlated with VEGFR2 (rAdj = 0.698, P < 0.001). There were inverse significant correlations between CoQ10 and the fold changes of AMPK (rAdj = - 0.276, P = 0.030), VEGF-A (rAdj = - 0.319, P = 0.011) and VEGFR2 (rAdj = - 0.262, P = 0.045). The correlation between CoQ10 and the fold changes of PFKFB3 was significantly progesterone receptor (PR) dependent (rAdj = - 0.284, P = 0.041). Plasma CoQ10 was correlated with VEGF-A in hormone receptor-dependent mode (ER + : rAdj = - 0.286, P = 0.032 and PR + : rAdj = - 0.313, P = 0.025). Our findings could provide new insights suggesting CoQ10 can inversely correlate to the expression levels of VEGF-A/VEGFR2 as angiogenic factors and AMPK/PFKFB3 as biomarkers for tumoral glycolysis, especially in a hormone receptor-dependent manner to possibly prevent the progression of breast carcinogenesis.

Aerosticca soli gen. nov., sp. nov., an aerobic gammaproteobacterium isolated from crude oil-contaminated soil.

An aerobic bacterium, designated strain Dysh456T, was isolated from a crude oil-contaminated soil. Cells of strain Dysh456T were rod-shaped, motile, and Gram-stain-negative. Strain Dysh456T grew at 13-48 °C and pH 4.3-7.9. Major cellular fatty acids were iso-C15:0 (42.5%), iso-C17:0 (15.3%) and summed feature 9 (iso-C17:1 ω9c/C16:0 10-methyl [13.7%]). Major respiratory quinone was ubiquinone-8. The genome of strain Dysh456T consists of a single circular chromosome of 2,874,969 bp in length with G + C content of 68.3%. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain Dysh456T belongs to the family Rhodanobacteraceae, but none of the existing genera can accommodate this novel isolate. On the basis of physiological, chemotaxonomic, and genomic properties, strain Dysh456T (= NBRC 112897T = DSM 105662T) is proposed as the type strain representing a novel species of novel genus, for which the name Aerosticca soli gen. nov., sp. nov. is proposed.

Hankyongella ginsenosidimutans gen. nov., sp. nov., isolated from mineral water with ginsenoside coverting activity.

In this study, a novel ginsenoside transforming bacterium, strain W1-2-3T, was isolated from mineral water. The 16S rRNA gene sequence analysis showed that strain W1-2-3T shares 93.7-92.2% sequence similarity with the members of the family Sphingomonadaceae and makes a group with Sphingoaurantiacus capsulatus YLT33T (93.7%) and S. polygranulatus MC 3718T (93.4%). The novel isolate efficiently hydrolyses the ginsenoside Rc to Rd. The genome comprises a single circular 2,880,809, bp chromosome with 3211 genes in total, and 1993 protein coding genes. The isolate was observed to grow at 10-37 °C and at pH 6-10 on R2A agar medium; maximum growth was found to occur at 25 °C and pH 7.0. Strain W1-2-3T was found to contain ubiquinone-10 as the predominant quinone and the fatty acids C16:1, C17:1ω6c, C14:0 2-OH, summed feature 3 (C16:1ω6c/C16:1ω7c) and summed feature 8 (C18:1ω6c/C18:1ω7c). The DNA G+C content was determined to be 65.9 mol%. Strain W1-2-3T can be distinguished from the other members of the family Sphingomonadaceae by a number of chemotaxonomic and phenotypic characteristics. The major polar lipids of strain W1-2-3T were identified as phosphatidylethanolamine, an unidentified glycolipid and an unidentified polar lipid. The major poly amine was found to be homospermidine. Based on polyphasic taxonomic analysis, strain W1-2-3T is concluded to represent a novel species within a new genus, for which the name Hankyongella ginsenosidimutans gen. nov., sp. nov. is proposed. The type strain of Hankyongella ginsenosidimutans is W1-2-3T (= KACC 18307T = LMG 28594T).

Sphingobium algorifonticola sp. nov., isolated from a cold spring.

Strain TLA-22T, isolated from a cold spring in Taiwan, was characterized using a polyphasic taxonomy approach. Cells were Gram-stain-negative, aerobic, poly-ß-hydroxybutyrate-accumulating, motile by means of a single polar flagellum, rod-shaped and formed bright yellow colonies. Optimal growth occurred at 20-25 °C, pH 6-6.5, and in the presence of 0.5 % NaCl. The major fatty acids of TLA-22T were C18 : 1 ω7 c and C17 : 1ω6c. The predominant hydroxy fatty acids were C15 : 0 2-OH and C14 : 0 2-OH. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidyldimethylethanolamine, sphingoglycolipid, an unidentified aminophospholipid, an unidentified phospholipid and three unidentified lipids. TLA-22T contained spermidine as the major polyamine and putrescine as the minor component. The only isoprenoid quinone was Q-10. The genomic DNA G+C content of TLA-22T was 63.2 mol%. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that TLA-22T was a mem,ber of a phylogenetic lineage including members of the genus Sphingobium. TLA-22T was most closely related to Sphingobium aromaticiconvertens RW16T, with a 97.4 % 16S rRNA gene sequence similarity. TLA-22T showed 74.8-75.7 % average nucleotide identity and 20.1-22.0 % digital DNA-DNA hybridization identity with the strains of other species of the genus Sphingobium. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain TLA-22T should be classified as representing a novel species of the genus Sphingobium, for which the name Sphingobium algorifonticola sp. nov. is proposed. The type strain is TLA-22T (=BCRC 81097T =LMG 30309T=KCTC 62189T).

Hahyoungchilella caricis gen. nov., sp. nov., isolated from a rhizosphere mudflat of a halophyte (Carex scabrifolia), transfer of Thioclava arenosa Thongphrom et al. 2017 to Pseudothioclava as Pseudothioclava arenosa gen. nov., comb. nov. and proposal of Thioclava electrotropha Chang et al. 2018 as a later heterosynonym of Thioclava sediminum.

A Gram-stain-negative strictly aerobic, marine bacterium, designated GH2-2T, was isolated from a rhizosphere mudflat of a halophyte (Carex scabrifolia) in Gangwha Island, the Republic of Korea. The cells of the organism were oxidase-positive, catalase-positive, flagellated, short rods that grew at 10-40°C, pH 4-10, and 0-13% (w/v) NaCl. The predominant ubiquinone was Q-10. The major polar lipids were phosphatidylcholine, phosphatidylethanolamine, and phosphatidylglycerol. The major fatty acid is C18:1. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the novel isolate formed an independent lineage at the base of the radiation encompassing members of the genus Thioclava, except for Thioclava arenosa. The closest relatives were T. nitratireducens (96.03% sequence similarity) and T. dalianensis (95.97%). The genome size and DNA G+C content were 3.77 Mbp and 59.6 mol%, respectively. Phylogenomic analysis supported phylogenetic distinctness based on 16S rRNA gene sequences. Average nucleotide identity values were 73.6-74.0% between the novel strain and members of the genus Thioclava. On the basis of data obtained from a polyphasic approach, the strain GH2-2T (= KCTC 62124T = DSM 105743) represents a novel species of a new genus for which the name Hahyoungchilella caricis gen. nov., sp. nov. is proposed. Moreover, the transfer of Thioclava arenosa Thongphrom et al. 2017 to Pseudothioclava gen. nov. as Pseudothioclava arenosa comb. nov. is also proposed. Finally, Thioclava electrotropha Chang et al. 2018 is proposed to be a later heterosynonym of Thioclava sediminum Liu et al. 2017.

Polyphasic taxonomic analysis of Paracoccus ravus sp. nov., an alphaproteobacterium isolated from marine sediment.

Polyphasic taxonomic analysis was performed on a novel marine bacterium, designated as strain YJ057T, isolated from marine sediment collected in the Republic of Korea. The strain was Gram-negative, beige-colored, facultatively anaerobic, coccoid or ovoid-shaped and nonmotile. Preliminary 16S rRNA gene sequence-based phylogenetic analysis indicated that this novel marine isolate belongs to the family Rhodobacteraceae of the class Alphaproteobacteria, and has the greatest (96.2%) sequence similarity to Paracoccus aestuariivivens GHD-30T. Major (>10%) fatty acids of strain YJ057T were C16:0 and C18:1 ω7c, G+C content in the genomic DNA of the strain was 63.6 mol% and the sole respiratory quinone was ubiquinone Q-10. It had phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine and some unidentified components (three aminolipids, a glycolipid, a phospholipid and two lipids). As per the distinct phylogenetic position and combination of phenotypic and genotypic traits, the strain is considered a novel species of the genus Paracoccus, and the name Paracoccus ravus sp. nov. is proposed.

Isolation and polyphasic identification of Tateyamaria armeniaca sp. nov.

A novel alphaproteobacterium, designated KMU-156T, was isolated from seawater collected on the coast of Jeju Island, Republic of Korea, and its phylogenetic position was determined using a polyphasic taxonomic approach. Strain KMU-156T was Gram-stain-negative, strictly aerobic, apricot-colored, rod-shaped, non-motile and chemoorganoheterotrophic. Phylogenetic study based on the 16S rRNA gene sequence revealed that the novel bacterium belongs to the family 'Rhodobacteraceae', of the class Alphaproteobacteria, and that it possessed the greatest sequence similarity (98.2%) with Tateyamaria omphalii MKT107T. DNA-DNA hybridization values between strains KMU-156T, T. omphalii KCTC 12333T and Tateyamaria pelophila DSM 17270T were less than 70%. The major isoprenoid quinone of the novel isolate was ubiquinone-10 (Q-10) and the major (> 10%) cellular fatty acids were C16:0 and C18:1 ω7c. The genomic DNA G + C content of strain KMU-156T was 59.3 mol%. The polar lipid profile of the strain KMU-156T had phosphatidylglycerol, phosphatidylcholine, an unidentified aminolipid, an unidentified phospholipid and two unidentified lipids. From the discriminative taxonomic features, the strain is considered to represent a novel species of the genus Tateyamaria for which the name Tateyamaria armeniaca sp. nov. is proposed. The type strain of T. armeniaca sp. nov. is KMU-156T (= KCCM 90321T = NBRC 113460T).

The kynurenine pathway is essential for rhodoquinone biosynthesis in Caenorhabditis elegans.

A key metabolic adaptation of some species that face hypoxia as part of their life cycle involves an alternative electron transport chain in which rhodoquinone (RQ) is required for fumarate reduction and ATP production. RQ biosynthesis in bacteria and protists requires ubiquinone (Q) as a precursor. In contrast, Q is not a precursor for RQ biosynthesis in animals such as parasitic helminths, and most details of this pathway have remained elusive. Here, we used Caenorhabditis elegans as a model animal to elucidate key steps in RQ biosynthesis. Using RNAi and a series of C. elegans mutants, we found that arylamine metabolites from the kynurenine pathway are essential precursors for RQ biosynthesis de novo Deletion of kynu-1, encoding a kynureninase that converts l-kynurenine (KYN) to anthranilic acid (AA) and 3-hydroxykynurenine (3HKYN) to 3-hydroxyanthranilic acid (3HAA), completely abolished RQ biosynthesis but did not affect Q levels. Deletion of kmo-1, which encodes a kynurenine 3-monooxygenase that converts KYN to 3HKYN, drastically reduced RQ but not Q levels. Knockdown of the Q biosynthetic genes coq-5 and coq-6 affected both Q and RQ levels, indicating that both biosynthetic pathways share common enzymes. Our study reveals that two pathways for RQ biosynthesis have independently evolved. Unlike in bacteria, where amination is the last step in RQ biosynthesis, in worms the pathway begins with the arylamine precursor AA or 3HAA. Because RQ is absent in mammalian hosts of helminths, inhibition of RQ biosynthesis may have potential utility for targeting parasitic infections that cause important neglected tropical diseases.

Paracoccus jeotgali sp. nov., isolated from Korean salted and fermented shrimp.

A Gram-stain-negative and facultatively aerobic bacterium, designated as strain CBA4604T, was isolated from a traditional Korean salted and fermented shrimp food (saeu-jeot). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain CBA4604T formed a clearly distinct phyletic lineage from closely related species within the genus Paracoccus. Strain CBA4604T was the most closely related to P. koreensis Ch05T (97.5% 16S rRNA gene sequence similarity) and other type strains (≤ 97.0%). The genome comprised a chromosome and two plasmids of 3,299,166 bp with 66.5% G+C content. The DNA-DNA relatedness values between strain CBA4604T and P. koreensis Ch05T, P. alcaliphilus DSM 8512T, and P. stylophorae KTW-16T were 30.5%, 22.9%, and 16.7%, respectively. Cells of the strain were short rod-shaped and oxidase- and catalase-positive. The growth of strain CBA-4604T was observed at 10-40°C (optimum, 37°C), pH 6.0-10.0 (optimum, pH 7.0), and in the presence of 0-8.0% (w/v) NaCl (optimum, 0-2.0%). Strain CBA4604T contained ubiquinone 10 as the sole isoprenoid quinone and summed feature 8 (C18:1ω7c/C18:1ω6c) and C18:0 as the major cellular fatty acids. The polar lipids consisted of phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phospholipid, an unidentified aminolipid, an unidentified glycolipid, and three unidentified lipids. Based on its phylogenetic, genomic, phenotypic, and chemotaxonomic features, we concluded that strain CBA-4604T represents a novel species in the genus Paracoccus and we propose the name Paracoccus jeotgali sp. nov. The type strain is CBA4604T (= KACC 19579T = JCM 32510T).