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1.
Appl Microbiol Biotechnol ; 104(5): 1883-1890, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31932892

RESUMO

C-Glycosides, a special type of glycoside, are frequently distributed in many kinds of medicinal plants, such as puerarin and mangiferin, showing various and significant bioactivities. C-Glycosides are usually characterized by the C-C bond that forms between the anomeric carbon of sugar moieties and the carbon atom of aglycon, which is usually resistant against acidic hydrolysis and enzymatic treatments. Interestingly, C-glycosides could be cleaved by several intestinal bacteria, but whether the enzymatic cleavage of C-C glycosidic bond is reduction or hydrolysis has been controversial; furthermore, whether existence of a "C-glycosidase" directly catalyzing the cleavage is not clear. Here we review research advances about the discovery and mechanism of intestinal bacteria in enzymatic cleavage of C-C glycosidic bond with an emphasis on the identification of enzymes manipulation the deglycosylation. Finally, we give a brief conclusion about the mechanism of C-glycoside deglycosylation and perspectives for future study in this field.


Assuntos
Bactérias/enzimologia , Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Glicosídeo Hidrolases/metabolismo , Glicosídeos/metabolismo , Intestinos/microbiologia , Animais , Bactérias/isolamento & purificação , Proteínas de Bactérias/genética , Biotransformação , Glicosídeo Hidrolases/genética , Glicosídeos/química , Glicosilação , Humanos , Estrutura Molecular
2.
Fish Shellfish Immunol ; 96: 152-160, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31794843

RESUMO

C-type lectins are Ca2+-dependent carbohydrate-binding proteins containing one or more carbohydrate-recognition domains (CRDs). C-type lectins play crucial roles in innate immunity, including nonself-recognition and pathogen elimination. In the present study, two C-type lectins (designated ReCTL-1 and ReCTL-2) were identified from the shrimp Rimicaris exoculata which dwells in deep-sea hydrothermal vents. The open reading frames of ReCTL-1 and ReCTL-2 encoded polypeptides of 171 and 166 amino acids respectively, which were both composed of a signal peptide and a single CRD. The key motifs determining the carbohydrate binding specificity of ReCTL-1 and ReCTL-2 were respectively Glu-Pro-Ala (EPA) and Gln-Pro-Asn (QPN), which were firstly discovered in R. exoculata. ReCTL-1 and ReCTL-2 displayed similar pathogen-associated molecular pattern (PAMP) binding features and they bound three PAMPs-ß-glucan, lipopolysaccharide and peptidoglycan-with relatively high affinity. In addition, both could efficiently recognize and bind Gram-positive bacteria, Gram-negative bacteria and fungi. However, ReCTL-1 and ReCTL-2 exhibited different microbial agglutination activities: ReCTL-1 agglutinated Staphylococcus aureus and Saccharomyces cerevisiae, while ReCTL-2 agglutinated Micrococcus luteus, Vibrio parahaemolyticus and V. fluvialis. Both ReCTL-1 and ReCTL-2 inhibited the growth of V. fluvialis. All these results illustrated that ReCTL-1 and ReCTL-2 could function as important pattern-recognition receptors with broad nonself-recognition spectra and be involved in immune defense against invaders, but their specificities are not the same. In addition, the two ReCTLs possessed different carbohydrate binding specificities from each other and from the classical pattern: ReCTL-1 with an EPA motif bound d-galactose and l-mannose, while ReCTL-2 with a QPN motif bound d-fucose and N-acetylglucosamine.

3.
J Microbiol ; 57(12): 1065-1072, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31562606

RESUMO

A yellow pigmented, Gram-stain-negative, aerobic bacterium designated A5.7T was studied to evaluate the taxonomic position following the modern polyphasic approach. The strain was isolated from sediments near Zhairuo Island, which is situated in the East China Sea. Cells were non-spore forming rods without flagella but showed motility by gliding. Growth was observed at 15-35°C (optimum 28°C), pH 6.0-9.0 (optimum pH 6.5) and 0-2% (w/v) NaCl (optimum 0-0.5%) in LB broth. The major respiratory quinone of A5.7T was menaquinone 6. The major polar lipid of A5.7T was phosphatidylethanolamine and the predominant fatty acids (> 5%) were iso-C15:0, iso-C17:0 3-OH, C15:1ω6c, iso-C15:0 3-OH, iso-C15:1 G, summed feature 3 (C16:1ω7c and/or C16:1ω6c) and summed feature 9 (iso-C17:1ω9c and/or C16:010-methyl). Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate belongs to the genus Flavobacterium and shares the highest sequence similarities with Flavobacterium sharifuzzamanii A7.6T (98.5%), Flavobacterium tistrianum GB 56.1T (98.3%), Flavobacterium nitrogenifigens NXU-44T (97.8%), Flavobacterium anhuiense D3T (97.6%), Flavobacterium ginsenosidimutans THG 01T (97.6%), and Flavobacterium foetidum CJ42T (97.6%). Digital DNA-DNA hybridization and average nucleotide identity values between the strain and its closest phylogenetic neighbors showed the ranges from 19.6 to 34.1% and 73.7 to 87.9%, respectively. Therefore, based on polyphasic characteristics, strain A5.7T represents a novel species of the genus Flavobacterium for which the name Flavobacterium zhairuonensis sp. nov. is proposed. The type strain is A5.7T (= KCTC 62406T = MCCC 1K03494T).


Assuntos
Flavobacterium/classificação , Flavobacterium/isolamento & purificação , Sedimentos Geológicos/microbiologia , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/análise , Flavobacterium/genética , Flavobacterium/fisiologia , Genoma Bacteriano/genética , Concentração de Íons de Hidrogênio , Hibridização de Ácido Nucleico , Fosfatidiletanolaminas/análise , Quinonas/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Cloreto de Sódio , Temperatura Ambiente , Vitamina K 2/análogos & derivados , Vitamina K 2/análise
5.
Curr Microbiol ; 76(9): 988-994, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31172271

RESUMO

Qipengyuania sediminis CGMCC 1.12928T, a family member of Erythrobacteraceae, the class of Alphaproteobacteria, was isolated from a borehole sediment sample collected from Qiangtang Basin in Qinghai-Tibetan Plateau, the largest permafrost in China. Understanding bacterial molecular feature may shed light on the ecological strategy in the extreme environment. Here we describe the complete genome sequence and annotation of strain CGMCC 1.12928T, including the complete genome sequence and annotation. The genome of strain CGMCC 1.12928T consist of a single-circular chromosome, comprises 2,416,000 bp with an average G + C content of 66.7 mol%, and contains 2414 genes; including 2367 CDSs, 44 tRNA genes, as well as one operon of 16S-23S-5S rRNA genes. Genomic properties indicated that strain CGMCC 1.12928T has a relatively smaller genome size and higher G + C content within the family Erythrobacteraceae. In addition, genomic analysis revealed its genome contains multiple function genes responsible for nitrogen, sulfur and phosphorus cycles and explained the cold adaption mechanism. Thus, this strain plays an active role in the biogeochemical cycle in cold niche. The whole-genome of this isolate will widen our understanding of the ecological role of the genus Qipengyuania in permafrost.


Assuntos
Alphaproteobacteria/isolamento & purificação , Genoma Bacteriano , Sedimentos Geológicos/microbiologia , Adaptação Fisiológica , Alphaproteobacteria/classificação , Alphaproteobacteria/genética , Alphaproteobacteria/fisiologia , Composição de Bases , China , Temperatura Baixa , DNA Bacteriano , Óperon , Pergelissolo/microbiologia , Filogenia , Sequenciamento Completo do Genoma
6.
Int J Syst Evol Microbiol ; 69(6): 1689-1695, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30942688

RESUMO

A Gram-stain-negative, rod-shaped bacterium, designated Ery1T, was isolated from deep-sea seawater collected from the Mariana Trench and subjected to a polyphasic investigation for taxonomy. Strain Ery1T was able to grow in medium containing 0-10 % NaCl (w/v; optimum, 0-1.0 %), pH 5.0-9.5 (optimum, pH 6.0-7.0) and at temperatures between 10-45 °C (optimum, 30-40 °C). The comparison of 16S rRNA gene sequences revealed that strain Ery1T showed highest similarity to Altererythrobacterxinjiangensis S3-63T (97.7 %) and Altererythrobacterrigui WW3T (97.6 %), and exhibited less than 97.5 % sequence similarity to other type strains of the species with validly published names. Phylogenetic analyses indicated that strain Ery1T fell within the cluster comprising the Altererythrobacter species and formed a coherent clade with Altererythrobacterxinjiangensis and Altererythrobactersoli. The OrthoANIu and in silico DNA-DNA hybridization values between strain Ery1T and the reference strains were 73.8-75.9 % and 19.2-20.1 %, respectively. Strain Ery1T contained Q-10 as the major respiratory quinone and Q-11 in a minor amount. The major fatty acids (>10 %) were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0, C18 : 1ω7c 11-methyl and C14 : 0 2-OH. The major polar lipids were sphingoglycolipid, diphosphatidylglycerol, phosphatidyglycerol, phatidylethanolamine, phosphatidylcholine and three unidentified glycolipids. Differential phenotypic properties, chemotaxonomic differences, phylogenetic distinctiveness, together with the genomic data demonstrated that strain Ery1T represents a novel species of the genus Altererythrobacter, for which named as Altererythrobacter aerophilus sp. nov. with the type strain Ery1T (=KCTC 62387T=CGMCC 1.16499T=MCCC 1A10037T).


Assuntos
Alphaproteobacteria/classificação , Filogenia , Água do Mar/microbiologia , Alphaproteobacteria/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Glicolipídeos/química , Hibridização de Ácido Nucleico , Oceano Pacífico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/análogos & derivados , Ubiquinona/química
7.
Biotechnol Lett ; 41(4-5): 591-604, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30895484

RESUMO

OBJECTIVE: We aimed to characterize a novel SGNH (Ser-Gly-Asn-His) family hydrolase from the annotated genome of marine bacteria with new features. RESULTS: A novel esterase Ali5 from Altererythrobacter ishigakiensis has been identified and classified into SGNH family. Ali5 presented a novel GNSL (Gly-Asn-Ser-Leu(X)) motif that differs from the classic GDSL (Gly-Asp-Ser-Leu(X)) motif of SGNH family. The enzyme has esterase and thioesterase activity and exhibited apparent temperature and pH optima of 40 °C and pH 7.5 (in phosphate buffer), respectively. Ali5 was found to be halotolerant and thermostable, and exhibited strong resistance to several organic solvents and metal ions. The residue Tyr196 has a great influence on the catalytic activity, which was proved by site-directed mutagenesis and subsequent kinetic characterization. CONCLUSION: The esterase Ali5 with esterase and thioesterase activities, salt and metal ions resistance and unique structural features was identified, which holds promise for research on the SGNH family of hydrolases.


Assuntos
Alphaproteobacteria/enzimologia , Motivos de Aminoácidos , Tioléster Hidrolases/genética , Tioléster Hidrolases/metabolismo , Alphaproteobacteria/genética , Cátions/metabolismo , Biologia Computacional , Análise Mutacional de DNA , Inibidores Enzimáticos/metabolismo , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Metais/metabolismo , Mutagênese Sítio-Dirigida , Solventes/metabolismo , Temperatura Ambiente , Tioléster Hidrolases/química , Tioléster Hidrolases/classificação
8.
Curr Microbiol ; 76(3): 297-303, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30603961

RESUMO

A novel bacterial strain A7.6T was isolated from the sediments collected near the Zhairuo Island located in the East China Sea and characterized using a polyphasic approach. Cells were Gram-stain-negative, rod-shaped, non-spore forming, non-flagellated but motile by gliding. The strain was aerobic, positive for oxidase and catalase activities. The strain can grow at 4-35 °C, pH 5.5-9.0, and 0-3% (w/v) NaCl concentration. The major polar lipid was phosphatidylethanolamine, the predominant fatty acids (> 10%) were iso-C15:0 and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c). The genomic G+C content was 33.6 mol% and the major respiratory quinone was menaquinone 6. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain A7.6T belonged to the genus Flavobacterium and was closely related to Flavobacterium tistrianum GB 56.1T (98.4% similarity), F. nitrogenifigens NXU-44T (98.4%), F. ginsenosidimutans THG 01T (98.0%) and F. anhuiense D3T (97.7%). Average nucleotide identities and digital DNA-DNA hybridizations values for genomes ranged from 75.9 to 91.4% and 21.4 to 43.9% between strain A7.6T and its closest phylogenetic neighbors. The polyphasic characterization indicated that strain A7.6T represented a novel species of the genus Flavobacterium, for which the name Flavobacterium sharifuzzamanii is proposed. The type strain is A7.6T (= KCTC 62405T = MCCC 1K03485T). The NCBI GenBank accession number for the 16S rRNA gene of A7.6T is MH396692, and for the genome sequence is QJGZ00000000. The digital protologue database (DPD) Taxon Number is TA00643.


Assuntos
Flavobacterium/classificação , Flavobacterium/fisiologia , Sedimentos Geológicos/microbiologia , Oceanos e Mares , Filogenia , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/análise , Flavobacterium/química , Genoma Bacteriano/genética , Concentração de Íons de Hidrogênio , Fosfolipídeos/análise , Quinonas/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Cloreto de Sódio , Temperatura Ambiente
9.
Am J Trop Med Hyg ; 100(3): 652-658, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30675836

RESUMO

This study aimed to assess baseline knowledge, attitudes, and practices about severe fever with thrombocytopenia syndrome (SFTS) and identify the target population for health education programs in endemic areas of Anhui, China. This cross-sectional study was conducted from May to June 2017. Of 752 participants, 383 (50.9%) were from Nanqiao District, 397 (52.8%) were female, and 430 (57.2%) were farmers; 37.4% had heard about SFTS, but knowledge of symptoms and signs including fever (34.2%), leukopenia (8.0%), and thrombocytopenia (10.1%) was low. Only 12.1% knew that SFTS virus is transmitted by ticks, 9.4% realized that the blood and body fluid of SFTS are infectious, and only 38.2% thought that the tick should be paralyzed using medical alcohol or iodine. Meanwhile, 61.3% wore long-sleeve clothes, whereas 20.2% used repellents. Median scores for knowledge, attitudes, and practices, and the total score were 4.0, 6.0, 5.0, and 16.0, respectively. Knowledge was influenced by region (OR = 0.632, 95% CI: 0.399-0.999), education (OR = 0.516, 95% CI: 0.434-0.612), gender (OR = 1.865, 95% CI: 1.165-2.987), and age (OR = 3.406, 95% CI: 2.345-4.947). Education was a predictor of lack of appreciation of infection risk (OR = 0.519, 95% CI: 0.449-0.599) and practice (OR = 0.481, 95% CI: 0.396-0.584). Our findings indicate that SFTS-related health education programs are required for females; participants from Qianshan Prefecture; those with an occupation of farmer, retiree, houseworker, or unemployed; elderly participants; and those with low education. Large-scale sustainable health education programs focusing on the target populations are urgently needed in endemic areas.


Assuntos
Infecções por Bunyaviridae/epidemiologia , Infecções por Bunyaviridae/virologia , Conhecimentos, Atitudes e Prática em Saúde , Phlebovirus , Adulto , Idoso , Infecções por Bunyaviridae/prevenção & controle , China/epidemiologia , Estudos Transversais , Coleta de Dados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
10.
Int J Syst Evol Microbiol ; 69(1): 241-248, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30480510

RESUMO

A Gram-stain-negative, strictly aerobic, rod-shaped bacterium, designated V18T, was isolated from a deep-sea sediment sample collected from the Pacific Ocean and subjected to a polyphasic taxonomic investigation. Cells of strain V18T grew in medium containing 0-10.0 % (w/v) NaCl (optimum 1.0 %), at pH 5.5-9.0 (optimum 6.5-7.0) and at 10-40 °C (optimum 30-37 °C). Aesculin and Tweens 20, 40, 60 and 80 were hydrolysed. The isolate contained carotenoid-like pigments and lacked bacteriochlorophyll a. Strain V18T was closely related to members of the genus Erythrobacter, namely Erythrobacter odishensis JA747T (98.9 % 16S rRNA gene sequence similarity), E. westpacificensis JLT2008T (98.8 %), E. gangjinensis K7-2T (97.7 %), E. aquimixticola JSSK-14T (97.6 %), E. marinus KCTC 23554T (97.4 %), E. atlanticus s21-N3T (97.3 %), E. arachoides RC4-10-4T (97.2 %), E. citreus RE35F/1T (97.1 %) and E. luteus KA37T (97.0 %), and exhibited less than 97.0 % sequence similarity with the type strains of other species with validly published names. Phylogenetic analyses revealed that strain V18T clustered with E. odishensis JA747T and formed an independent lineage. The average nucleotide identity and in silico DNA-DNA hybridization values between strain V18T and the type strains of Erythrobacter species were 70.5-83.4 % and 18.4-26.1 %, respectively. Strain V18T contained ubiquinone 10 (Q-10) as the sole respiratory quinone. The major fatty acids (>10 %) were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The major polar lipids were sphingoglycolipid (SGL), diphosphatidylglycerol (DPG), phosphatidyglycerol (PG), phosphatidylethanolamine (PE) and one unidentified lipid (L1). The DNA G+C content was 62.6 mol%. According to the phenotypic, chemotaxonomic and phylogenetic data, strain V18T represents a novel species of the genus Erythrobacter, for which the name Erythrobacter zhengii is proposed. The type strain is V18T (=KCTC 62389T=MCCC 1K03475T).


Assuntos
Sedimentos Geológicos/microbiologia , Filogenia , Água do Mar/microbiologia , Sphingomonadaceae/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Oceano Pacífico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Sphingomonadaceae/isolamento & purificação , Ubiquinona/análogos & derivados , Ubiquinona/química
11.
Int J Syst Evol Microbiol ; 69(1): 278-284, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30499768

RESUMO

A Gram-stain-negative, strictly aerobic, motile by one polar flagellum, non-spore-forming, rod-shaped bacterium, designated as 190T, was isolated from seawater of the West Pacific Ocean and subjected to a polyphasic taxonomic investigation. Colonies were 1.0-2.0 mm in diameter, smooth, circular, convex and white after growth on marine agar at 30 °C for 24 h. Strain 190T was found to grow at 4-40 °C (optimum, 30 °C), at pH 5.5-10.5 (optimum, pH 6.5) and with 0.5-12.5 % (w/v) NaCl (optimum, 2.0 %). Chemotaxonomic analysis showed the sole respiratory quinone was ubiquinone 8 (Q-8), and the major fatty acids were summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), C16 : 0 and summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c). The major polar lipids were phosphatidylethanolamine (PE), phosphatidylglycerol (PG), one unidentified aminolipid (AL1) and two unidentified glycolipids (GL1, GL2). The DNA G+C content of strain 190T was 48.7 mol% based on the genome sequence. The comparison of 16S rRNA gene sequence similarities showed that strain 190T was closely related to Alteromonas oceani S35T (99.6 % sequence similarity), A. lipolytica JW12T (98.2 %), A. aestuariivivens JDTF-113T (97.7 %) and A. mediterranea DET (97.5 %); it exhibited 97.0 % or less sequence similarity with the type strains of other species with validly published names. Phylogenetic trees reconstructed with the neighbour-joining, maximum-parsimony and maximum-likelihood methods based on 16S rRNA gene sequences showed that strain 190T constituted a separate branch with A. oceani, A. confluentis, A. aestuariivivens and A. lipolytica in a clade of the genus Alteromonas. OrthoANI values between strain 190T and A. oceani S35T and A. lipolytica JW12T were 93.5 and 77.9 %, respectively, and in silico DNA-DNA hybridization values were 53.8 and 21.2 %, respectively. Differential phenotypic properties, together with phylogenetic distinctiveness, demonstrated that strain 190T is clearly distinct from recognized species of the genus Alteromonas. On the basis of these features, we propose that strain 190T (=MCCC 1K03456T=KCTC 62227T) represents a novel species of the genus Alteromonas with the name Alteromonas alba sp. nov.


Assuntos
Alteromonas/classificação , Filogenia , Água do Mar/microbiologia , Alteromonas/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Glicolipídeos/química , Hibridização de Ácido Nucleico , Oceano Pacífico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/química
12.
Nat Prod Res ; 33(12): 1819-1823, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29430942

RESUMO

In this study, three active compounds isolated from Oceanobacillus sp. XC22919 were identified as 2-methyl-N-(2'-phenylethyl) butyramide (1), 3-methyl-N-(2'-phenylethyl)-butyramide (2) and benzyl benzoate (3), and were first reported to exhibit the apparent quorum sensing inhibitory activities against C. violaceum 026 and P. aeruginosa. Compounds 1-3 inhibited violacein production of C. violaceum 026 by 10.5-55.7, 11.2-55.7, and 27.2%-95.7%, respectively, and inhibited pyocyanin production of P. aeruginosa by 1.7-50.8, 39.1-90.7, and 57.2%-98.7%, respectively. The azocasein-degrading proteolytic rates of P. aeruginosa were observed by 13.4-31.5, 13.4-28.8, and 11.3%-21.1%, respectively. With respect to elastase, the range of inhibition of activity of compounds 1-3 was 2.1-30.3, 4.2-18.2, and 8.9%-15.7%, respectively. Compounds 1 and 3 also showed a concentration-dependent attenuation in biofilm formation, with the maximum of 50.6% inhibition, and 37.7% inhibition at 100 µg/mL, respectively.


Assuntos
Amidas/farmacologia , Antibacterianos/farmacologia , Bacillaceae/química , Butiratos/farmacologia , Chromobacterium/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Percepção de Quorum/efeitos dos fármacos , Amidas/administração & dosagem , Antibacterianos/administração & dosagem , Biofilmes/efeitos dos fármacos , Butiratos/administração & dosagem , Chromobacterium/metabolismo , Chromobacterium/patogenicidade , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Indóis/antagonistas & inibidores , Indóis/metabolismo , Pseudomonas aeruginosa/patogenicidade , Piocianina/biossíntese , Água do Mar/microbiologia
13.
Langmuir ; 35(5): 1858-1863, 2019 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-30080053

RESUMO

Horseradish peroxidase (HRP) holds great potential in wastewater treatment. However, its instability in harsh environments remains a major issue. Various immobilization technologies were developed to retain enzyme stability at the cost of its effectiveness. We demonstrate that zwitterionic encapsulation of HRP retained both protein stability and activity to a large degree. In a water treatment study, encapsulating HRP into a zwitterionic nanogel resulted in a three-fold increase in the catalytic oxidation efficiency of phenol molecules. In addition, zwitterionic nanocapsules exhibited the best performance when compared with nanocapsules made from other hydrophilic polymers. These results indicated that zwitterionic HRP nanocapsules hold great potential in the decontamination of organic pollutants from wastewater.

14.
Int J Syst Evol Microbiol ; 68(12): 3856-3862, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30325296

RESUMO

Two Gram-stain-negative, strictly aerobic, non-motile, non-spore-forming, rod-shaped bacteria, designated as SY3-15Tand SY3-13, were isolated from a seawater sample of the South China Sea. Colonies were 0.5-1.0 mm in diameter, smooth, circular, convex and translucent after growth on marine agar at 37 °C for 3 days. The strains were found to grow at 20-50 °C (optimum, 42 °C), pH 6.0-8.5 (optimum, pH 6.5-7.5) and with 0.5-6.0 % (w/v) NaCl (optimum, 1.5-2.0 %). Chemotaxonomic analysis showed the sole respiratory quinone to be ubiquinone-10, the major fatty acids (>10 %) were C16 : 0 3-OH, C19 : 0cyclo ω9c, C18 : 1 3-OH and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), and the polar lipids were phosphatidylglycerol, two unidentified aminolipids and three unidentified lipids. The DNA G+C content was 67.2-67.4 mol% calculated by genome. The 16S rRNA gene sequences of strains SY3-15T and SY3-13 were identical and related to the genus Lutibaculum with a similarity of 92.1 %. The 16S rRNA gene phylogenetic trees reconstructed with neighbour-joining, maximum-parsimony and minimum-evolution methods showed that the strains constituted a deep and separated branch from other families of Alphaproteobacteria, and the phylogenetic trees based on concatenated 163 protein sequences from genome sequences showed that the clade in which strains SY3-15T and SY3-13 located was separated from the clade of the other orders of Alphaproteobacteria, indicating it may represent a novel family of a novel order. Based on their phenotypic properties and their phylogenetic distinctiveness, we propose strains SY3-15T (=MCCC 1K03467T=KCTC 62335T) and SY3-13 (=MCCC 1K03466=KCTC 62329) to represent a novel species of a novel genus with the name Minwuia thermotolerans gen. nov., sp. nov., and we propose Minwuiaceae fam. nov. and Minwuiales ord. nov. with Minwuia as the type genus.


Assuntos
Alphaproteobacteria/classificação , Filogenia , Água do Mar/microbiologia , Alphaproteobacteria/genética , Alphaproteobacteria/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/química
15.
Int J Syst Evol Microbiol ; 68(9): 3156-3162, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30095388

RESUMO

A Gram-stain-negative bacterium, designated NH169-3T, was isolated from a surface seawater sample of the South China Sea and subjected to a taxonomic polyphasic investigation. Strain NH169-3T was strictly aerobic, non-motile, non-spore-forming and rod-shaped. The colony was 1.0-2.0 mm in diameter after the growth on marine agar at 30 °C for 72 h. The centre of the colony was smooth, circular, convex and brown with a transparent periphery. Strain NH169-3T was able to grow at temperatures between 4-40 °C (optimum, 37 °C), pH 5.5-9.0 (pH 7.5) and with 0-12.5 % (w/v) NaCl (3.0 %). Chemotaxonomic analysis showed that the sole respiratory quinone of strain NH169-3T was ubiquinone 9; major fatty acids were C16 : 0 and C18 : 1ω9c, and major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and one unidentified glycolipid. The DNA G+C content was 52.7 mol%. The comparison of 16S rRNA gene sequences showed that strain NH169-3T was closely related to Marinobacter shengliensis SL013A34A2T with a similarity of 98.0 %. Three phylogenetic trees reconstructed with neighbour-joining, maximum-parsimony and maximum-likelihood methods using 16S rRNA gene sequences showed that strain NH169-3T was grouped into a separated branch with M. shengliensis SL013A34A2T in a clade of the genus Marinobacter and closely related to Marinobacter halophilus JCM 30472T, Marinobacter vinifirmus DSM 17747T and Marinobacter hydrocarbonoclasticus DSM 8798T. Analyses of both phenotypic and phylogenetic properties have suggested that strain NH169-3T was distinctive from species with validly published names in genus Marinobacter. Thus, strain NH169-3T (=MCCC 1K03455T=KCTC 62226T) is proposed as a novel species in genus Marinobacter with the name Marinobacter fuscus sp. nov.


Assuntos
Marinobacter/classificação , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Glicolipídeos/química , Marinobacter/genética , Marinobacter/isolamento & purificação , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/química
16.
BMC Genomics ; 19(1): 385, 2018 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-29792177

RESUMO

BACKGROUND: Type strains of the genus Porphyrobacter belonging to the family Erythrobacteraceae and the class Alphaproteobacteria have been isolated from various environments, such as swimming pools, lake water and hot springs. P. cryptus DSM 12079T and P. tepidarius DSM 10594T out of all Erythrobacteraceae type strains, are two type strains that have been isolated from geothermal environments. Next-generation sequencing (NGS) technology offers a convenient approach for detecting situational types based on protein sequence differences between thermophiles and mesophiles; amino acid substitutions can lead to protein structural changes, improving the thermal stabilities of proteins. Comparative genomic studies have revealed that different thermal types exist in different taxa, and few studies have been focused on the class Alphaproteobacteria, especially the family Erythrobacteraceae. In this study, eight genomes of Porphyrobacter strains were compared to elucidate how Porphyrobacter thermophiles developed mechanisms to adapt to thermal environments. RESULTS: P. cryptus DSM 12079T grew optimally at 50 °C, which was higher than the optimal growth temperature of other Porphyrobacter type strains. Phylogenomic analysis of the genus Porphyrobacter revealed that P. cryptus DSM 12079T formed a distinct and independent clade. Comparative genomic studies uncovered that 1405 single-copy genes were shared by Porphyrobacter type strains. Alignments of single-copy proteins showed that various types of amino acid substitutions existed between P. cryptus DSM 12079T and the other Porphyrobacter strains. The primary substitution types were changes from glycine/serine to alanine. CONCLUSIONS: P. cryptus DSM 12079T was the sole thermophile within the genus Porphyrobacter. Phylogenomic analysis and amino acid frequencies indicated that amino acid substitutions might play an important role in the thermophily of P. cryptus DSM 12079T. Bioinformatic analysis revealed that major amino acid substitutional types, such as changes from glycine/serine to alanine, increase the frequency of α-helices in proteins, promoting protein thermostability in P. cryptus DSM 12079T. Hence, comparative genomic analysis broadens our understanding of thermophilic mechanisms in the genus Porphyrobacter and may provide a useful insight in the design of thermophilic enzymes for agricultural, industrial and medical applications.


Assuntos
Alphaproteobacteria/genética , Alphaproteobacteria/fisiologia , Genômica , Temperatura Ambiente , Substituição de Aminoácidos , Genoma Bacteriano/genética , Filogenia
17.
Int J Syst Evol Microbiol ; 68(5): 1713-1718, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29611802

RESUMO

A Gram-stain-negative, aerobic, non-motile and rod-shaped bacterium, designated LA399T, was isolated from deep-sea sediment collected from the Pacific Ocean. Cells of strain LA399T grew in the medium containing 0-10.0 % of NaCl (w/v; optimum 3.0-5.0 %), pH 6.5-8.0 (optimum 7.0) and 20-40 °C (optimum 37 °C). Aesculin, gelatin, starch and Tween 80 were hydrolysed. Strain LA399T was closely related to Gracilimonas halophila WDS2C40T (97.0 % sequence similarity), Gracilimonas mengyeensis YIM J14T (96.4 %), Gracilimonas rosea CL-KR2T (96.4 %) and Gracilimonas tropica DSM 19535T (96.0 %), and exhibited equal or less than 96.0 % sequence similarity to other type strains of species with validly published names. Phylogenetic analyses revealed that strain LA399T clustered with the clade comprising the Gracilimonas species and formed an independent lineage. Strain LA399T contained menaquinone 7 as the sole isoprenoid quinone and iso-C15 : 0, anteiso-C15 : 0, summed feature 3 (C16 : 1ω7c/C16 : 1ω6c) and summed feature 9 (iso-C17 : 1ω9c/10-methyl C16 : 0) as the predominant cellular fatty acids. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid and three unidentified glycolipids. The DNA G+C content was 45.3 mol%. According to the phylogenetic, chemotaxonomic and phenotypic data, it represents a novel species of the genus Gracilimonas, for which the name Gracilimonas amylolytica is proposed. The type strain is LA399T (=CGMCC 1.16248T=KCTC 52885T).


Assuntos
Sedimentos Geológicos/microbiologia , Bacilos e Cocos Aeróbios Gram-Negativos/classificação , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Bacilos e Cocos Aeróbios Gram-Negativos/genética , Bacilos e Cocos Aeróbios Gram-Negativos/isolamento & purificação , Oceano Pacífico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
18.
Fish Shellfish Immunol ; 78: 238-247, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29678793

RESUMO

Galectins are ß-galactoside binding lectins that play crucial roles in innate immunity in vertebrates and invertebrates through their conserved carbohydrate-recognition domains (CRDs). In the present study, single- and four-CRD-containing galectins were identified in oyster Crassostrea gigas (designated CgGal-2 and CgGal-3). The open reading frames (ORFs) of CgGal-2 and CgGal-3 encode polypeptides of 200 and 555 amino acids, respectively. All CRDs of CgGal-3 include two consensus motifs essential for ligand-binding, and a novel motif is present in CgGal-2. Pathogen-associated molecular pattern (PAMP) profiles were determined for recombinant rCgGal-2 and rCgGal-3, and rCgGal-2 displayed low binding affinity for PAMPs, while rCgGal-3 bound various PAMPs including glucan, lipopolysaccharide (LPS), and peptidoglycan (PGN) with relatively high affinity. Furthermore, rCgGal-2 and rCgGal-3 exhibited different microbe binding profiles; rCgGal-2 bound to Gram-negative bacteria (Escherichia coli and Vibrio vulnificus) and fungi (Saccharomyces cerevisiae and Pichia pastoris), while rCgGal-3 bound to these microbes but also to Gram-positive bacteria (Micrococcus luteus). In addition, rCgGal-3 possessed microbial agglutinating activity and coagulation activity against fungi and erythrocytes, respectively, but rCgGal-2 lacked any agglutinating activity. Carbohydrate binding specificity analysis showed that rCgGal-3 specifically bound D-galactose. Furthermore, rCgGal-2 and rCgGal-3 functioned as opsonin participating in the clearance against invaders in C. gigas. Thus, CgGal-2 with one CRD and CgGal-3 with four CRDs are new members of the galectin family involved in immune responses against bacterial infection. Differences in the organisation and amino acid sequences of CRDs may affect their specificity and affinity for nonself substances.


Assuntos
Crassostrea/genética , Galectina 2/genética , Galectina 3/genética , Regulação da Expressão Gênica/imunologia , Imunidade Inata/genética , Sequência de Aminoácidos , Animais , Crassostrea/imunologia , Fungos/fisiologia , Galectina 2/química , Galectina 2/imunologia , Galectina 3/química , Galectina 3/imunologia , Perfilação da Expressão Gênica , Bactérias Gram-Negativas/fisiologia , Bactérias Gram-Positivas/fisiologia , Filogenia , Alinhamento de Sequência
19.
Microb Cell Fact ; 17(1): 16, 2018 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-29382330

RESUMO

BACKGROUND: The deep-sea environment harbors a vast pool of novel enzymes. Owing to the limitations of cultivation, cultivation-independent has become an effective method for mining novel enzymes from the environment. Based on a deep-sea sediment metagenomics library, lipolytic-positive clones were obtained by activity-based screening methods. RESULTS: Two novel esterases, DMWf18-543 and DMWf18-558, were obtained from a deep-sea metagenomic library through activity-based screening and high-throughput sequencing methods. These esterases shared 80.7% amino acid identity with each other and were determined to be new members of bacterial lipolytic enzyme family IV. The two enzymes showed the highest activities toward p-nitrophenyl (p-NP) butyrate at pH 7.0 and 35-40 °C and were found to be resistant to some metal ions (Ba2+, Mg2+, and Sr2+) and detergents (Triton X-100, Tween 20, and Tween 80). DMWf18-543 and DMWf18-558 exhibited distinct substrate specificities and preferences. DMWf18-543 showed a catalytic range for substrates of C2-C8, whereas DMWf18-558 presented a wider range of C2-C14. Additionally, DMWf18-543 preferred p-NP butyrate, whereas DMWf18-558 preferred both p-NP butyrate and p-NP hexanoate. To investigate the mechanism underlying the phenotypic differences between the esterases, their three-dimensional structures were compared by using homology modeling. The results suggested that residue Leu199 of DMWf18-543 shortens and blocks the substrate-binding pocket. This hypothesis was confirmed by the finding that the DMWf18-558-A199L mutant showed a similar substrate specificity profile to that of DMWf18-543. CONCLUSIONS: This study characterized two novel homologous esterases obtained from a deep-sea sediment metagenomic library. The structural modeling and mutagenesis analysis provided insight into the determinants of their substrate specificity and preference. The characterization and mechanistic analyses of these two novel enzymes should provide a basis for further exploration of their potential biotechnological applications.


Assuntos
Esterases/genética , Esterases/isolamento & purificação , Sedimentos Geológicos/microbiologia , Leucina , Metagenoma , Estabilidade Enzimática , Esterases/química , Biblioteca Gênica , Sedimentos Geológicos/química , Sequenciamento de Nucleotídeos em Larga Escala , Concentração de Íons de Hidrogênio , Leucina/metabolismo , Metagenômica/métodos , Conformação Molecular , Filogenia , Água do Mar/microbiologia , Alinhamento de Sequência , Análise de Sequência de DNA , Especificidade por Substrato , Temperatura Ambiente
20.
Int J Syst Evol Microbiol ; 68(1): 461-466, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29292687

RESUMO

Advancement of DNA sequencing technology allows the routine use of genome sequences in the various fields of microbiology. The information held in genome sequences proved to provide objective and reliable means in the taxonomy of prokaryotes. Here, we describe the minimal standards for the quality of genome sequences and how they can be applied for taxonomic purposes.


Assuntos
Genômica/normas , Filogenia , Células Procarióticas/classificação , Análise de Sequência de DNA/normas , Terminologia como Assunto
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