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1.
Arch Microbiol ; 202(8): 2127-2133, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32506148

RESUMO

A Gram-stain-negative, strictly aerobic, non-flagellated, gliding, rod-shaped bacterium, designated C1T was isolated from the coastal sediment of Xiaoshi Island, Weihai, China. Phylogenetic analysis of the 16S rRNA gene and the genome sequence of the newly isolated strain revealed that it belonged to the genus Psychroflexus within the family Flavobacteriaceae. The 16S rRNA gene sequence similarities between strain C1T and the type strains of Psychroflexus members ranged from 91.6 to 94.9%. The AAI, POCP, ANI and dDDH values between strain C1T and Psychroflexus torquis ATCC 700755T were 67.0%, 53.1%, 70.5% and 20.2%, respectively. The DNA G+C content was 34.0 mol%. Strain C1T grows optimally at 28-30 â„ƒ, at pH 7.5-8.0 and with 3.0-5.0% (w/v) NaCl, and its colonies were orange-colored, convex and circular on the MA plate. Positive for hydrolysis of Tween 20 and catalase activities. The dominant respiratory quinone was menaquinone-6, and the major fatty acids were iso-C17:0 3-OH and iso-C15:0. The polar lipids of strain C1T consisted of phosphatidylethanolamine and three unidentified lipids. On the basis of phylogenetic, phenotypic and chemotaxonomic data, it is considered that strain C1T represents a novel species within the genus Psychroflexus, for which, the name Psychroflexus maritimus sp. nov., is proposed. The type strain is C1T (= MCCC 1H00415T = KCTC 72796T).


Assuntos
Flavobacteriaceae/classificação , Sedimentos Geológicos/microbiologia , Filogenia , Técnicas de Tipagem Bacteriana , Composição de Bases , Ácidos Graxos/química , Flavobacteriaceae/química , Flavobacteriaceae/genética , Flavobacteriaceae/isolamento & purificação , Genoma Bacteriano/genética , Pigmentação , RNA Ribossômico 16S/genética , Água do Mar/microbiologia , Especificidade da Espécie
2.
Nature ; 583(7815): 314-318, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32499654

RESUMO

Light-driven sodium pumps actively transport small cations across cellular membranes1. These pumps are used by microorganisms to convert light into membrane potential and have become useful optogenetic tools with applications in neuroscience. Although the resting state structures of the prototypical sodium pump Krokinobacter eikastus rhodopsin 2 (KR2) have been solved2,3, it is unclear how structural alterations over time allow sodium to be translocated against a concentration gradient. Here, using the Swiss X-ray Free Electron Laser4, we have collected serial crystallographic data at ten pump-probe delays from femtoseconds to milliseconds. High-resolution structural snapshots throughout the KR2 photocycle show how retinal isomerization is completed on the femtosecond timescale and changes the local structure of the binding pocket in the early nanoseconds. Subsequent rearrangements and deprotonation of the retinal Schiff base open an electrostatic gate in microseconds. Structural and spectroscopic data, in combination with quantum chemical calculations, indicate that a sodium ion binds transiently close to the retinal within one millisecond. In the last structural intermediate, at 20 milliseconds after activation, we identified a potential second sodium-binding site close to the extracellular exit. These results provide direct molecular insight into the dynamics of active cation transport across biological membranes.


Assuntos
Flavobacteriaceae/química , Rodopsinas Microbianas/química , Rodopsinas Microbianas/efeitos da radiação , ATPase Trocadora de Sódio-Potássio/química , ATPase Trocadora de Sódio-Potássio/efeitos da radiação , Sítios de Ligação , Cristalografia , Elétrons , Transporte de Íons , Isomerismo , Lasers , Prótons , Teoria Quântica , Retinaldeído/química , Retinaldeído/metabolismo , Bases de Schiff/química , Sódio/metabolismo , Análise Espectral , Eletricidade Estática , Fatores de Tempo
3.
Mar Drugs ; 18(1)2020 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-31940773

RESUMO

Many marine microorganisms synthesize exopolysaccharides (EPSs), and some of these EPSs have been reported to have potential in different fields. However, the pharmaceutical potentials of marine EPSs are rarely reported. The EPS secreted by the Artic marine bacterium Polaribacter sp. SM1127 has good antioxidant activity, outstanding moisture-retention ability, and considerable protective property on human dermal fibroblasts (HDFs) at low temperature. Here, the effects of SM1127 EPS on skin wound healing and frostbite injury prevention were studied. Scratch wound assay showed that SM1127 EPS could stimulate the migration of HDFs. In the full-thickness cutaneous wound experiment of Sprague-Dawley (SD) rats, SM1127 EPS increased the wound healing rate and stimulated tissue repair detected by macroscopic observation and histologic examination, showing the ability of SM1127 EPS to promote skin wound healing. In the skin frostbite experiment of SD rats, pretreatment of rat skin with SM1127 EPS increased the rate of frostbite wound healing and promoted the repair of the injured skin significantly, indicating the good effect of SM1127 EPS on frostbite injury prevention. These results suggest the promising potential of SM1127 EPS in the pharmaceutical area to promote skin wound healing and prevent frostbite injury.


Assuntos
Produtos Biológicos/farmacologia , Flavobacteriaceae/química , Congelamento das Extremidades/prevenção & controle , Polissacarídeos Bacterianos/farmacologia , Pele/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Animais , Fibroblastos/efeitos dos fármacos , Humanos , Polissacarídeos Bacterianos/química , Ratos , Pele/citologia
4.
Molecules ; 25(1)2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31906348

RESUMO

The synthesis of bioplastic from marine microbes has a great attendance in the realm of biotechnological applications for sustainable eco-management. This study aims to isolate novel strains of poly-ß-hydroxybutyrate (PHB)-producing bacteria from the mangrove rhizosphere, Red Sea, Saudi Arabia, and to characterize the extracted polymer. The efficient marine bacterial isolates were identified by the phylogenetic analysis of the 16S rRNA genes as Tamlana crocina, Bacillus aquimaris, Erythrobacter aquimaris, and Halomonas halophila. The optimization of PHB accumulation by E. aquimaris was achieved at 120 h, pH 8.0, 35 °C, and 2% NaCl, using glucose and peptone as the best carbon and nitrogen sources at a C:N ratio of 9.2:1. The characterization of the extracted biopolymer by Fourier-transform infrared spectroscopy (FTIR), Nuclear magnetic resonance (NMR), and Gas chromatography-mass spectrometry (GC-MS) proves the presence of hydroxyl, methyl, methylene, methine, and ester carbonyl groups, as well as derivative products of butanoic acid, that confirmed the structure of the polymer as PHB. This is the first report on E. aquimaris as a PHB producer, which promoted the hypothesis that marine rhizospheric bacteria were a new area of research for the production of biopolymers of commercial value.


Assuntos
Biopolímeros/biossíntese , Biopolímeros/química , Hidroxibutiratos/química , Hidroxibutiratos/metabolismo , Poliésteres/química , Poliésteres/metabolismo , Sphingomonadaceae/química , Sphingomonadaceae/metabolismo , Avicennia/microbiologia , Bacillus/química , Bacillus/genética , Bacillus/metabolismo , Biopolímeros/análise , Carbono/química , Carbono/metabolismo , Fermentação , Flavobacteriaceae/química , Flavobacteriaceae/genética , Flavobacteriaceae/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Halomonas/química , Halomonas/genética , Halomonas/metabolismo , Hidroxibutiratos/análise , Espectroscopia de Ressonância Magnética , Nitrogênio/química , Nitrogênio/metabolismo , Filogenia , Poliésteres/análise , RNA Ribossômico 16S/genética , Rizosfera , Salinidade , Arábia Saudita , Água do Mar/microbiologia , Espectroscopia de Infravermelho com Transformada de Fourier , Sphingomonadaceae/genética , Sphingomonadaceae/isolamento & purificação , Temperatura
5.
Curr Microbiol ; 77(2): 294-299, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31776653

RESUMO

A Gram-stain-negative, strictly aerobic and moderately halophilic bacterium, designated strain AsT0115T, was isolated from a red marine alga, Asparagopsis taxiformis. Cells were non-motile rods showing oxidase-positive and catalase-negative activities. Growth was observed at 15-37 C (optimum, 25 C) and pH 6.5-7.5 (optimum, pH 7.0) and in the presence of 0-11.0% (w/v) NaCl (optimum, 2.0-3.0%). Strain AsT0115T contained iso-C15:0 and iso-C15:1 G as the predominant fatty acids. Menaquinone-6 was identified as the sole isoprenoid quinone. Major polar lipids consisted of phosphatidylethanolamine, an identified aminolipid and three unidentified polar lipids. The G+C content of the genomic DNA calculated from the whole genome sequence was 41.7 mol%. Strain AsT0115T was most closely related to Flagellimonas pacifica sw169T and Flagellimonas flava DSM 22638T with 96.5% and 95.6% 16S rRNA gene sequence similarities, respectively. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain AsT0115T formed a phyletic lineage with F. pacifica sw169T within the genus Flagellimonas. Phenotypic, chemotaxonomic, and phylogenetic features clearly suggested that strain AsT0115T represents a novel species of the genus Flagellimonas, for which the name Flagellimonas algicola sp. nov. is proposed. The type strain is AsT0115T (= KACC 19790T = JCM 32942T).


Assuntos
Flavobacteriaceae/classificação , Flavobacteriaceae/genética , Filogenia , Rodófitas/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Flavobacteriaceae/química , Flavobacteriaceae/isolamento & purificação , Fosfolipídeos/química , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
6.
Molecules ; 24(21)2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31694159

RESUMO

Two bacterial isolates from the Barents Sea, both belonging to the genus Algibacter, were found to yield extracts with anti-bacterial bioactivity. Mass spectrometry guided dereplication and purification of the active extracts lead to the isolation of the same active principle in both extracts. The structure of the bioactive compound was identified via mass spectrometry and nuclear resonance spectroscopy and it turned out to be the known lipopeptide Lipid 430. We discovered and determined its previously unknown anti-bacterial activity against Streptococcus agalactiae and revealed a cytotoxic effect against the A2058 human melanoma cell line at significantly lower concentrations compared to its anti-bacterial concentration. Flow cytometry and microscopy investigations of the cytotoxicity against the melanoma cell line indicated that Lipid 430 did not cause immediate cell lysis. The experiments with melanoma cells suggest that the compound functions trough more complex pathways than acting as a simple detergent.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Citotoxinas/química , Citotoxinas/farmacologia , Flavobacteriaceae/química , Lipídeos/química , Lipídeos/farmacologia , Linhagem Celular Tumoral , Células HT29 , Humanos , Espectroscopia de Ressonância Magnética/métodos , Espectrometria de Massas/métodos , Melanoma/tratamento farmacológico , Streptococcus agalactiae/efeitos dos fármacos
7.
Biochem Biophys Res Commun ; 518(3): 479-485, 2019 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-31427080

RESUMO

Isoprenoids comprise a diverse group of natural products with a broad range of metabolic functions. Isoprenoids are synthesized from prenyl pyrophosphates by prenyltransferases that catalyze the isoprenoid chain-elongation process to different chain lengths. We hereby present the crystal structure of geranylgeranyl pyrophosphate synthase from the marine flavobacterium Nonlabens dokdonensis DSW-6 (NdGGPPS). NdGGPPS forms a hexamer composed of homodimeric trimer, and the monomeric structure is composed of 15 α-helices (α1-α15). In this structure, we observed the binding of one pyrophosphate molecule and two glycerol molecules that mimicked substrate binding to the enzyme. The substrate binding site of NdGGPPS contains large hydrophobic residues such as Phe, His and Tyr, and structural and amino acids sequence analyses thereof suggest that the protein belongs to the short-chain prenyltransferase family.


Assuntos
Proteínas de Bactérias/química , Flavobacteriaceae/química , Geranil-Geranildifosfato Geranil-Geraniltransferase/química , Sequência de Aminoácidos , Cristalografia por Raios X , Modelos Moleculares , Conformação Proteica , Conformação Proteica em alfa-Hélice , Multimerização Proteica , Alinhamento de Sequência
8.
Biochem Biophys Res Commun ; 517(2): 390-397, 2019 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-31358319

RESUMO

Although core xylose on glycoproteins has been implicated in allergy, infection and other biological processes, research on core xylose modification is rare. The lack of a ß-d-xylosidase that can catalytically remove the core xylose directly from glycoproteins is a reason for this. Through functional genomic analysis, we identified a glycoprotein core xylosidase and named it gpcXase I. gpcXase I is located immediately downstream of glycoprotein core fucosidase cFase I in Elizabethkingia meningoseptica. These two genes form a functional operon for glycoprotein core modifications. Three acidic residues (Asp-200, Asp-304 and Glu-649) were identified as key catalytic sites for gpcXase I activity, suggesting a unique triacdic mechanize for its activity. Asp-200 was identified a novel and essential base catalysts in the catalytic process, Asp-304 and Glu-649 was function as catalytic nucleophiles and acid catalysts, respectively. In addition, IgE-specific reactions were detected in 55% of serum samples collected from 40 allergic patients, and the reactions were significantly attenuated by removal of the core xylose of the allergen by treatment with gpcXase I. gpcXase I is a novel tool for basic and clinical glycomics.


Assuntos
Proteínas de Bactérias/metabolismo , Flavobacteriaceae/metabolismo , Glicoproteínas/metabolismo , Xilose/metabolismo , Xilosidases/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Domínio Catalítico , Flavobacteriaceae/química , Flavobacteriaceae/genética , Infecções por Flavobacteriaceae/microbiologia , Humanos , Cinética , Modelos Moleculares , Filogenia , Alinhamento de Sequência , Especificidade por Substrato , Xilosidases/química , Xilosidases/genética
9.
Science ; 364(6445)2019 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-31196985

RESUMO

Chemical defense against predators is widespread in natural ecosystems. Occasionally, taxonomically distant organisms share the same defense chemical. Here, we describe an unusual tripartite marine symbiosis, in which an intracellular bacterial symbiont ("Candidatus Endobryopsis kahalalidefaciens") uses a diverse array of biosynthetic enzymes to convert simple substrates into a library of complex molecules (the kahalalides) for chemical defense of the host, the alga Bryopsis sp., against predation. The kahalalides are subsequently hijacked by a third partner, the herbivorous mollusk Elysia rufescens, and employed similarly for defense. "Ca E. kahalalidefaciens" has lost many essential traits for free living and acts as a factory for kahalalide production. This interaction between a bacterium, an alga, and an animal highlights the importance of chemical defense in the evolution of complex symbioses.


Assuntos
Clorófitas , Flavobacteriaceae/metabolismo , Gastrópodes , Glicosídeos/metabolismo , Comportamento Predatório , Simbiose , Triterpenos/metabolismo , Animais , Evolução Biológica , Flavobacteriaceae/química
10.
Antonie Van Leeuwenhoek ; 112(11): 1645-1653, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31218499

RESUMO

A bacterial strain designated RZ03T was isolated from an intertidal sand sample from the Yellow Sea in China and characterised using a polyphasic taxonomic approach. Cells of strain RZ03T were observed to be Gram-stain negative, aerobic, and oxidase and catalase positive rods showing gliding motility and forming yellow colonies. Growth was found to occur at 7-30 °C (optimum, 25 °C), at pH 5.5-9.5 (optimum, pH 6.5-7.0) and with 0.5-5% NaCl (optimum, 1.5-2%). Phylogenetic analysis based on 16S rRNA gene sequences indicates that strain RZ03T clusters within members of the genus Flavivirga of the family Flavobacteriaceae and is closely related to the type strains Flavivirga amylovorans JCM 17112T and Flavivirga jejuensis JCM 17113T (97.9% and 97.5% similarity, respectively). The predominant cellular fatty acids are iso-C15:0, iso-C15:1 G, iso-C17:0 3-OH and iso-C15:0 3-OH and the major respiratory quinone is MK-6. Polar lipids include phosphatidylethanolamine, three unidentified aminolipids, an unidentified phospholipid and four unidentified lipids. The genome of strain RZ03T is 4.88 Mbp with a G+C content of 32.2 mol%. A total of 4152 genes are predicted, with 4052 protein-coding genes, 51 RNA genes and 49 pseudogenes. This polyphasic study suggests that strain RZ03T represents a novel species in the genus Flavivirga, for which the name Flavivirga rizhaonensis is proposed. The type strain is RZ03T(= KCTC 62833T = MCCC 1K03615T).


Assuntos
Organismos Aquáticos , Flavobacteriaceae/classificação , Flavobacteriaceae/isolamento & purificação , Areia/microbiologia , Composição de Bases , Flavobacteriaceae/química , Flavobacteriaceae/genética , Genoma Bacteriano , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
11.
J Agric Food Chem ; 67(16): 4595-4602, 2019 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-30907589

RESUMO

Aflatoxin B1 (AFB1), is a type I carcinogen that is one of the strongest naturally occurring aflatoxins and can be injurious to humans and livestock upon ingestion, inhalation, or skin contact, with carcinogenic and mutagenic effects. It causes significant hazardous effects to the food- and animal-production industries. We found a bacterial strain, 3J2MO, that degraded AFB1 well, and here we tested and characterized its AFB1-degradation ability. The strain degraded about 93.82% of the AFB1 after incubation for 48 h in Luria-Bertani (LB) medium at 37 °C with a final concentration of 100 ppb and an inoculation quantity of 1 × 107 cfu/mL. High-performance liquid chromatography-fluorescence detection (HPLC-FLD) was used to determine AFB1 amounts. The maximum degradation rates were 89.23% at pH 8.5; 55.78% at an inoculation quantity of 1 × 108 cfu/mL; and 71.50 and 71.21% at 34 and 37 °C, respectively. Treatment with sucrose and soluble starch as carbon sources and beef extract and ammonium acetate as nitrogen sources stimulated the degradation rate. Mg2+ and Ca2+ ions were activators for AFB1 degradation; however, Mn2+, Fe3+, Zn2+, and Cu2+ were strong inhibitors. This bacterial strain has potential in bioremediation and the detoxification of aflatoxin contamination for biocontrol strategies in both agricultural products and food-industry matrices.


Assuntos
Aflatoxina B1/metabolismo , Flavobacteriaceae/metabolismo , Aflatoxina B1/análise , Biodegradação Ambiental , Cromatografia Líquida de Alta Pressão , Meios de Cultura/química , Meios de Cultura/metabolismo , Flavobacteriaceae/química , Concentração de Íons de Hidrogênio , Sacarose/análise , Sacarose/metabolismo
12.
Mar Biotechnol (NY) ; 21(3): 416-429, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30874930

RESUMO

Considering the global trend in the search for alternative natural compounds with antioxidant and sun protection factor (SPF) boosting properties, bacterial carotenoids represent an opportunity for exploring pigments of natural origin which possess high antioxidant activity, lower toxicity, no residues, and no environmental risk and are readily decomposable. In this work, three pigmented bacteria from the Antarctic continent, named Arthrobacter agilis 50cyt, Zobellia laminarie 465, and Arthrobacter psychrochitiniphilus 366, were able to withstand UV-B and UV-C radiation. The pigments were extracted and tested for UV absorption, antioxidant capacity, photostability, and phototoxicity profile in murine fibroblasts (3T3 NRU PT-OECD TG 432) to evaluate their further potential use as UV filters. Furthermore, the pigments were identified by ultra-high-performance liquid chromatography-photodiode array detector-mass spectrometry (UPLC-PDA-MS/MS). The results showed that all pigments presented a very high antioxidant activity and good stability under exposure to UV light. However, except for a fraction of the A. agilis 50cyt pigment, they were shown to be phototoxic. A total of 18 different carotenoids were identified from 23 that were separated on a C18 column. The C50 carotenes bacterioruberin and decaprenoxanthin (including its variations) were confirmed for A. agilis 50cyt and A. psychrochitiniphilus 366, respectively. All-trans-bacterioruberin was identified as the pigment that did not express phototoxic activity in the 3T3 NRU PT assay (MPE < 0.1). Zeaxanthin, ß-cryptoxanthin, ß-carotene, and phytoene were detected in Z. laminarie 465. In conclusion, carotenoids identified in this work from Antarctic bacteria open perspectives for their further biotechnological application towards a more sustainable and environmentally friendly way of pigment exploitation.


Assuntos
Arthrobacter/química , Biotecnologia , Flavobacteriaceae/química , Pigmentos Biológicos/química , Regiões Antárticas , Carotenoides/química , Carotenoides/isolamento & purificação , Microbiologia Industrial , Pigmentos Biológicos/isolamento & purificação
13.
Antonie Van Leeuwenhoek ; 112(3): 479-490, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30302647

RESUMO

An iridescent yellow pigmented bacterium isolated from the Antarctic continent, named Cellulophaga fucicola strain 416, was found to be able to tolerate UV-B radiation. Its crude pigment extract was tested for antioxidant capacity, UV light stability and phototoxicity profile against murine fibroblast lines. The pigments were further isolated and chemically identified by ultra-high-performance liquid chromatography with photodiode array and mass spectrometry detectors. The results showed that the pigment extract presented weak stability under exposure to UV light, a phototoxic profile in the 3t3 Neutral Red Uptake test and a very high antioxidant activity, suggesting that it could be used as food and feed colourants. Zeaxanthin and two isomers of zeaxanthin, ß-cryptoxanthin and ß-carotene, were identified using a C18 column. These five carotenoids were the major pigments isolated from C. fucicola 416. In conclusion, the identification of pigments produced by the bacterial strain under study may help us understand how bacteria thrive in high UV and cold environments, and opens avenues for further biotechnological application towards a more sustainable and environmentally friendly way of pigment exploitation.


Assuntos
Antioxidantes/análise , Carotenoides/análise , Flavobacteriaceae/química , Flavobacteriaceae/isolamento & purificação , Pigmentos Biológicos/análise , Animais , Regiões Antárticas , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Carotenoides/química , Carotenoides/isolamento & purificação , Carotenoides/farmacologia , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Flavobacteriaceae/efeitos da radiação , Espectrometria de Massas , Camundongos , Pigmentos Biológicos/química , Pigmentos Biológicos/isolamento & purificação , Pigmentos Biológicos/farmacologia , Raios Ultravioleta
14.
Arch Microbiol ; 201(4): 499-504, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30386885

RESUMO

A novel marine flavobacterial species, designated 3KA7-17T, was isolated from the hard coral Acropora formosa D. collected in Japan. The strain was pale-orange pigmented, Gram-stain negative, strictly aerobic, coccus shaped, and non-motile. Preliminary analysis based on the 16S rRNA gene sequence revealed an affiliation with the family Flavobacteriaceae of the phylum Bacteroidetes, and it had the greatest sequence similarity (96.0%) to Seonamhaeicola algicola Gy8T. The DNA G + C content was 34.3 mol%. MK-6 was the major menaquinone, with iso-C15:1 H and/or C13:0 3-OH (24.3%), iso-C15:0 (19.5%), iso-C15:0 3-OH (14.2%), and iso-C17:0 3-OH (15.9%) as the main (> 10%) cellular fatty acids. The major polar lipid profile consisted of phosphatidylethanolamine, two unidentified aminolipids, and two unidentified lipids. Based on distinct phylogenetic and phenotypic evidence, the strain represents a novel species of the genus Seonamhaeicola, for which the name Seonamhaeicola acroporae sp. nov. is proposed and the type strain is 3KA7-17T (= KCTC 62713T = NBRC 113410T).


Assuntos
Antozoários/microbiologia , Flavobacteriaceae/classificação , Animais , Composição de Bases , DNA Bacteriano/química , Ácidos Graxos/análise , Flavobacteriaceae/química , Flavobacteriaceae/isolamento & purificação , Lipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , Vitamina K 2/análise
15.
J Biomater Appl ; 33(6): 819-833, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30449254

RESUMO

Since synthetic nerve conduits do not exhibit ideal regeneration characteristics, they are generally inadequate substitutes for autologous nerve grafts in the repair of long peripheral nerve defects. To resolve this problem, in this study, a nerve regeneration acellular nerve graft (ANG) with homologous dental pulp stem cells (DPSCs) was constructed. Xenogeneic ANG was processed by Myroilysin to completely remove cells and myelin sheath, while preserving extracellular matrix (ECM) microstructure of the natural nerve. The study revealed that ANG could support cell attachment and proliferation and did not stimulate a vigorous host rejection response. After inoculation of rabbit DPSCs (r-DPSCs) onto ANG, cells were observed to align along the longitudinal axis of the acellular nerve matrix (ANM) and persistently express NGF and BDNF. Undifferentiated r-DPSCs also presented glial cell characteristics and promoted nerve regeneration after transplantation in vivo. We repaired 1 cm purebred New Zealand White Rabbits sciatic nerve defects using this nerve graft construction, and nerve gap regeneration was indicated by electrophysiological and histological analysis. Therefore, we conclude that the combination of an ANG processed by Myroilysin with DPSCs providing a microenvironment that increases nerve regeneration for repairing peripheral nerve defects.


Assuntos
Metaloproteases/química , Regeneração Nervosa , Transplante de Células-Tronco , Células-Tronco/citologia , Tecidos Suporte/química , Animais , Proteínas de Bactérias , Células Cultivadas , Polpa Dentária/citologia , Matriz Extracelular/química , Flavobacteriaceae/química , Neurogênese , Ratos , Ratos Sprague-Dawley , Nervo Isquiático/lesões
16.
Nat Prod Res ; 33(24): 3559-3562, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29882431

RESUMO

Luteoloside (luteolin-7-O-glucoside), the biomarker of Lonicera japonica, was efficiently bio-synthetized from its cheaper precursor luteolin. The structure of luteoloside was characterized by LC-MS and NMR analyses. Compared to the significant inhibitory effect of luteolin on human hepatocyte cell line LO2 at high doses, luteoloside did not show obvious cytotoxic effects at any test dose. Moreover, luteoloside exhibited obvious promotive effects on human hepatocyte cells, suggesting a potential application in hepatoprotective therapies.


Assuntos
Bactérias/metabolismo , Flavobacteriaceae/química , Flavonas/isolamento & purificação , Glucosídeos/isolamento & purificação , Lonicera/química , Luteolina/isolamento & purificação , Rizosfera , Linhagem Celular , Flavobacteriaceae/metabolismo , Flavonas/química , Glucosídeos/biossíntese , Glucosídeos/química , Glucosídeos/farmacologia , Humanos , Lonicera/microbiologia , Luteolina/biossíntese , Luteolina/química , Luteolina/farmacologia , Estrutura Molecular , Substâncias Protetoras
17.
Clin Microbiol Infect ; 25(3): 340-345, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29689427

RESUMO

OBJECTIVES: Rapid identification of Elizabethkingia species is essential because these species show variations in antibiotic susceptibility and clinical outcomes. Many recent inaccuracies in Elizabethkingia identification by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) have been noted. Accordingly, in this study, we evaluated the use of MALDI-TOF MS with an amended database to identify isolates of Elizabethkingia anophelis, E. miricola and E. meningoseptica. We then investigated the antimicrobial susceptibility of Elizabethkingia. METHODS: MALDI-TOF MS spectra were acquired from formic acid extracts overlaid with α-cyano-4-hydroxycinnamic acid matrix on target slides in linear positive ion mode for m/z 2000 to 20 000 Da. Spectra were analysed and SuperSpectra were created with SARAMIS premium software. 16S rRNA gene sequencing was used as the reference standard for species identification. Antibiotic susceptibility was assessed by broth microdilution. RESULTS: A total of 103 E. anophelis, 21 E. miricola and 11 E. meningoseptica isolates were used to calculate the average spectra and exclude common peaks. SuperSpectra were added to the SARAMIS taxonomy database; all validation results were correct, even for isolates not included in SuperSpectra. Confirmation by direct colony formation was also performed. Overall, the positive predictive value of SuperSpectra was 100% for all isolates. E. miricola (77%, 17/22) was more susceptible to levofloxacin than E. anophelis (16%, 17/105). Doxycycline and minocycline were effective against all Elizabethkingia species. CONCLUSIONS: Spectral analysis software identified significant species-specific peaks to create reference masses for efficient and accurate identification of Elizabethkingia species, providing accurate information for clinical treatment of Elizabethkingia infections.


Assuntos
Antibacterianos/farmacologia , Infecções por Flavobacteriaceae/microbiologia , Flavobacteriaceae/classificação , Flavobacteriaceae/efeitos dos fármacos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , RNA Polimerases Dirigidas por DNA/genética , Flavobacteriaceae/química , Flavobacteriaceae/isolamento & purificação , Humanos , Testes de Sensibilidade Microbiana , RNA Ribossômico 16S/genética , Reprodutibilidade dos Testes , Análise de Sequência de DNA , Software , Especificidade da Espécie
18.
J Biol Chem ; 293(41): 15889-15900, 2018 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-30166338

RESUMO

Class I ribonucleotide reductase (RNR) consists of a catalytic subunit (NrdA) and a radical-generating subunit (NrdB) that together catalyze reduction of ribonucleotides to their corresponding deoxyribonucleotides. NrdB from the firmicute Facklamia ignava is a unique fusion protein with N-terminal add-ons of a glutaredoxin (Grx) domain followed by an ATP-binding domain, the ATP cone. Grx, usually encoded separately from the RNR operon, is a known RNR reductant. We show that the fused Grx domain functions as an efficient reductant of the F. ignava class I RNR via the common dithiol mechanism and, interestingly, also via a monothiol mechanism, although less efficiently. To our knowledge, a Grx that uses both of these two reaction mechanisms has not previously been observed with a native substrate. The ATP cone is in most RNRs an N-terminal domain of the catalytic subunit. It is an allosteric on/off switch promoting ribonucleotide reduction in the presence of ATP and inhibiting RNR activity in the presence of dATP. We found that dATP bound to the ATP cone of F. ignava NrdB promotes formation of tetramers that cannot form active complexes with NrdA. The ATP cone bound two dATP molecules but only one ATP molecule. F. ignava NrdB contains the recently identified radical-generating cofactor MnIII/MnIV We show that NrdA from F. ignava can form a catalytically competent RNR with the MnIII/MnIV-containing NrdB from the flavobacterium Leeuwenhoekiella blandensis In conclusion, F. ignava NrdB is fused with a Grx functioning as an RNR reductant and an ATP cone serving as an on/off switch.


Assuntos
Glutarredoxinas/metabolismo , Ribonucleotídeo Redutases/metabolismo , Aerococcaceae/química , Catálise , Nucleotídeos de Desoxiadenina/metabolismo , Flavobacteriaceae/química , Transferência Genética Horizontal , Glutarredoxinas/química , Glutarredoxinas/genética , Oxirredução , Ligação Proteica , Domínios Proteicos , Multimerização Proteica/efeitos dos fármacos , Ribonucleotídeo Redutases/genética
19.
Planta Med ; 84(18): 1363-1371, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29991081

RESUMO

Zobellia galactanivorans has been reported as a seaweed-associated or marine-derived species with largely unknown secondary metabolites. The combination of bioinformatic analysis and MS- and bioactivity guided separation led to the isolation of a new antibiotically active dialkylresorcin from the marine bacterium Z. galactanivorans. The antibiotic profile of the new dialkylresorcin zobelliphol (1: ) was investigated and compared with related and naturally occurring dialkyresorcins (i.e., stemphol (2: ) and 4-butyl-3,5-dihydroxybenzoic acid (3: )) from the marine-derived fungus Stemphylium globuliferum. Bacterial reporter strain assays provided insights into the mode of action of this antibiotic compound class. We identified an interference with bacterial DNA biosynthesis for the dialkylresorcin derivative 1: . In addition, the putative biosynthetic gene cluster corresponding to production of 1: was identified and a biosynthetic hypothesis was deduced.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Flavobacteriaceae/química , Resorcinóis/química , Resorcinóis/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Anti-Infecciosos/isolamento & purificação , Organismos Aquáticos , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/genética , DNA Bacteriano/biossíntese , Avaliação Pré-Clínica de Medicamentos/métodos , Flavobacteriaceae/metabolismo , Genes Reporter , Bactérias Gram-Positivas/efeitos dos fármacos , Células HeLa , Humanos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Estrutura Molecular , Resorcinóis/isolamento & purificação
20.
Arch Microbiol ; 200(8): 1159-1165, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29872888

RESUMO

A novel marine bacterium, designated KMU-57T, was isolated from seawater collected from the Republic of Korea, and it was characterized using polyphasic taxonomic methods. Strain KMU-57T was Gram-stain-negative, strictly aerobic, rod-shaped, motile and dark-yellow-pigmented. Comparative analysis based on the 16S rRNA gene sequence showed the affiliation of the isolate with members of the family Flavobacteriaceae of the phylum Bacteroidetes, and it had the greatest sequence similarity (97.6%) to Lacinutrix jangbogonensis PAMC 27137T. The DNA-DNA relatedness value between strain KMU-57T and L. jangbogonensis PAMC 27137T was 37.8 ± 2.2%. The DNA G + C content of strain KMU-57T was 29.9 mol%; MK-6 was the major menaquinone with; iso-C15:1 G (18.6%) and C16:1 ω7c and/or C16:1 ω6c (15.8%) as the major (> 10%) cellular fatty acids. The polar lipid profile consisted of phosphatidylethanolamine, three unidentified aminolipids, and five unidentified lipids. The strain represents a novel species of the genus Lacinutrix for which the name Lacinutrix salivirga sp. nov. is proposed. The type strain of L. salivirga sp. nov. is KMU-57T (= KCTC 52878T = NBRC 112845T).


Assuntos
Flavobacteriaceae/classificação , Água do Mar/microbiologia , Composição de Bases , DNA Bacteriano/química , Ácidos Graxos/química , Flavobacteriaceae/química , Flavobacteriaceae/genética , Flavobacteriaceae/isolamento & purificação , Fosfatidiletanolaminas/análise , RNA Ribossômico 16S/genética , Vitamina K 2/análise
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