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1.
Int J Biol Macromol ; 131: 10-18, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30851325

RESUMO

Marine bacteria secrete exopolysaccharides (EPS) with unique structural and functional properties and serve as a source of newer bioactive biopolymers. This study reports an EPS produced by a marine bacterium identified as Alteromonas sp. PRIM-28 for its bioactivities. The EPS was characterised using standard methods and tested for its bioactivities using in vitro models. EPS-A28 is an anionic heteropolysaccharide with a molecular weight of 780 kDa and exists as triple helical structure in aqueous solution. Monosaccharide composition is mannuronic acid, glucose and N-acetyl glucosamine repeating units in the ratio 1:3.67:0.93. The FT-IR spectra showed the presence of sulphate, phosphate and uronic acid residues. The thermal analysis showed partial degradation of the EPS-A28 at 190 °C and 40% of residues were stable up to 800 °C. It showed biocompatibility and induced proliferation and migration of dermal fibroblasts (HDF) and keratinocytes. EPS-A28 could increase the S-phase of cell cycle. The proliferative property of the EPS-A28 was established by the increased expression of fibroblast proliferation marker (Ki-67) also its capability of binding to cell surface. It also induced nitric oxide and arginase synthesis in macrophages. These findings suggest that EPS-A28 can be potentially used as a multifunctional bioactive polymer in wound care.


Assuntos
Alteromonas/química , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Biomarcadores , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Fibroblastos , Humanos , Queratinócitos , Camundongos , Peso Molecular , Monossacarídeos , Células RAW 264.7 , Termodinâmica
2.
Mar Drugs ; 17(1)2019 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-30669426

RESUMO

Articular cartilage is an avascular, non-innervated connective tissue with limited ability to regenerate. Articular degenerative processes arising from trauma, inflammation or due to aging are thus irreversible and may induce the loss of the joint function. To repair cartilaginous defects, tissue engineering approaches are under intense development. Association of cells and signalling proteins, such as growth factors, with biocompatible hydrogel matrix may lead to the regeneration of the healthy tissue. One current strategy to enhance both growth factor bioactivity and bioavailability is based on the delivery of these signalling proteins in microcarriers. In this context, the aim of the present study was to develop microcarriers by encapsulating Transforming Growth Factor-ß1 (TGF-ß1) into microparticles based on marine exopolysaccharide (EPS), namely GY785 EPS, for further applications in cartilage engineering. Using a capillary microfluidic approach, two microcarriers were prepared. The growth factor was either encapsulated directly within the microparticles based on slightly sulphated derivative or complexed firstly with the highly sulphated derivative before being incorporated within the microparticles. TGF-ß1 release, studied under in vitro model conditions, revealed that the majority of the growth factor was retained inside the microparticles. Bioactivity of released TGF-ß1 was particularly enhanced in the presence of highly sulphated derivative. It comes out from this study that GY785 EPS based microcarriers may constitute TGF-ß1 reservoirs spatially retaining the growth factor for a variety of tissue engineering applications and in particular cartilage regeneration, where the growth factor needs to remain in the target location long enough to induce robust regenerative responses.


Assuntos
Alteromonas/química , Portadores de Fármacos/química , Polissacarídeos/química , Fator de Crescimento Transformador beta1/administração & dosagem , Disponibilidade Biológica , Cartilagem Articular/efeitos dos fármacos , Cartilagem Articular/fisiologia , Linhagem Celular , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/farmacocinética , Portadores de Fármacos/isolamento & purificação , Composição de Medicamentos/métodos , Implantes de Medicamento , Liberação Controlada de Fármacos , Humanos , Fontes Hidrotermais/microbiologia , Microfluídica , Polissacarídeos/isolamento & purificação , Regeneração/efeitos dos fármacos , Tecidos Suporte/química , Fator de Crescimento Transformador beta1/farmacocinética
3.
Harmful Algae ; 80: 72-79, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30502814

RESUMO

The relationship between algicidal bacteria and harmful-algal-bloom-forming dinoflagellates is understudied and their action modes are largely uncharacterized. In this study, an algicidal bacterium (FDHY-03) was isolated from a bloom of Prorocentrum donghaiense and the characteristics of its action against P. donghaiense was investigated at physiological, molecular, biochemical and cytological levels. 16S rDNA sequence analysis placed this strain in the genus of Alteromonas in the subclass of γ-proteobacteria. Algicidal activity was detected in the bacterial filtrate, suggesting a secreted algicidal principle from this bacterium. Strain FDHY-03 showed algicidal activity on a broad range of HAB-forming species, but the greatest effect was found on P. donghaiense, which showed 91.7% mortality in 24 h of challenge. Scanning electron microscopic analysis indicated that the megacytic growth zone of P. donghaiense cells was the major target of the algicidal action of FDHY-03. When treated with FDHY-03 culture filtrate, P. donghaiense cell wall polysaccharides decreased steadily, suggesting that the algicidal activity occurred through the digestion of cell wall polysaccharides. To verify this proposition, the expression profile of beta-glucosidase gene in FDHY-03 cultures with or without P. donghaiense cell addition was investigated using reverse-transcription quantitative PCR. The gene expression level increased in the presence of P. donghaiense cells, indicative of beta-glucosidase induction by P. donghaiense and the enzyme's role in this dinoflagellate's demise. This study has isolated a new bacterial strain with a strong algicidal capability, documented its action mode and biochemical mechanism, providing a potential source of bacterial agent to control P. donghaiense blooms.


Assuntos
Alteromonas/isolamento & purificação , Dinoflagelados/efeitos dos fármacos , Herbicidas/farmacologia , Alteromonas/química , Alteromonas/genética , Agentes de Controle Biológico , Filogenia , Água do Mar/microbiologia
4.
J Enzyme Inhib Med Chem ; 33(1): 920-935, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29768059

RESUMO

Pentabromopseudilin (PBrP) is a marine antibiotic isolated from the marine bacteria Pseudomonas bromoutilis and Alteromonas luteoviolaceus. PBrP exhibits antimicrobial, anti-tumour, and phytotoxic activities. In mammalian cells, PBrP is known to act as a reversible and allosteric inhibitor of myosin Va (MyoVa). In this study, we report that PBrP is a potent inhibitor of transforming growth factor-ß (TGF-ß) activity. PBrP inhibits TGF-ß-stimulated Smad2/3 phosphorylation, plasminogen activator inhibitor-1 (PAI-1) protein production and blocks TGF-ß-induced epithelial-mesenchymal transition in epithelial cells. PBrP inhibits TGF-ß signalling by reducing the cell-surface expression of type II TGF-ß receptor (TßRII) and promotes receptor degradation. Gene silencing approaches suggest that MyoVa plays a crucial role in PBrP-induced TßRII turnover and the subsequent reduction of TGF-ß signalling. Because, TGF-ß signalling is crucial in the regulation of diverse pathophysiological processes such as tissue fibrosis and cancer development, PBrP should be further explored for its therapeutic role in treating fibrotic diseases and cancer.


Assuntos
Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Miosina Tipo V/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Pirróis/farmacologia , Receptores de Fatores de Crescimento Transformadores beta/antagonistas & inibidores , Fator de Crescimento Transformador beta/antagonistas & inibidores , Alteromonas/química , Animais , Linhagem Celular , Relação Dose-Resposta a Droga , Células HEK293 , Células Hep G2 , Humanos , Vison , Estrutura Molecular , Miosina Tipo V/metabolismo , Proteínas Serina-Treonina Quinases/biossíntese , Pseudomonas/química , Pirróis/química , Pirróis/isolamento & purificação , Receptor do Fator de Crescimento Transformador beta Tipo II , Receptores de Fatores de Crescimento Transformadores beta/biossíntese , Relação Estrutura-Atividade , Fator de Crescimento Transformador beta/metabolismo
5.
BMC Biotechnol ; 17(1): 84, 2017 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-29149843

RESUMO

BACKGROUND: The identification of microorganisms with excellent flocculant-producing capability and optimization of the fermentation process are necessary for the wide-scale application of bioflocculants. Thus, we evaluated the flocculant-producing ability of a novel strain identified by the screening of marine bacteria, and we report for the first time the properties of the bioflocculant produced by Alteromonas sp. in the treatment of dye wastewater. RESULTS: A bioflocculant-producing bacterium was isolated from seawater and identified as Alteromonas sp. CGMCC 10612. The optimal carbon and nitrogen sources for the strain were 30 g/L glucose and 1.5 g/L wheat flour. In a 2-L fermenter, the flocculating activity and bioflocculant yield reached maximum values of 2575.4 U/mL and 11.18 g/L, respectively. The bioflocculant was separated and showed good heat and pH stability. The purified bioflocculant was a proteoglycan consisting of 69.61% carbohydrate and 21.56% protein (wt/wt). Infrared spectrometry further indicated the presence of hydroxyl, carboxyl and amino groups preferred for flocculation. The bioflocculant was a nanoparticle polymer with an average mass of 394,000 Da. The purified bioflocculant was able to remove Congo Red, Direct Black and Methylene Blue at efficiencies of 98.5%, 97.9% and 72.3% respectively. CONCLUSIONS: The results of this study indicated that the marine strain Alteromonas sp. is a good candidate for the production of a novel bioflocculant and suggested its potential industrial utility for biotechnological processes.


Assuntos
Alteromonas/química , Organismos Aquáticos/química , Corantes/isolamento & purificação , Águas Residuárias/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Carbono/metabolismo , Corantes/análise , Corantes/química , Floculação , Nitrogênio/metabolismo , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química
6.
Mar Drugs ; 15(6)2017 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-28604644

RESUMO

Most marine bacteria can produce exopolysaccharides (EPS). However, very few structures of EPS produced by marine bacteria have been determined. The characterization of EPS structure is important for the elucidation of their biological functions and ecological roles. In this study, the structure of EPS produced by a marine bacterium, Alteromonas sp. JL2810, was characterized, and the biosorption of the EPS for heavy metals Cu2+, Ni2+, and Cr6+ was also investigated. Nuclear magnetic resonance (NMR) analysis indicated that the JL2810 EPS have a novel structure consisting of the repeating unit of [-3)-α-Rhap-(1→3)-α-Manp-(1→4)-α-3OAc-GalAp-(1→]. The biosorption of the EPS for heavy metals was affected by a medium pH; the maximum biosorption capacities for Cu2+ and Ni2+ were 140.8 ± 8.2 mg/g and 226.3 ± 3.3 mg/g at pH 5.0; however, for Cr6+ it was 215.2 ± 5.1 mg/g at pH 5.5. Infrared spectrometry analysis demonstrated that the groups of O-H, C=O, and C-O-C were the main function groups for the adsorption of JL2810 EPS with the heavy metals. The adsorption equilibrium of JL2810 EPS for Ni2+ was further analyzed, and the equilibrium data could be better represented by the Langmuir isotherm model. The novel EPS could be potentially used in industrial applications as a novel bio-resource for the removal of heavy metals.


Assuntos
Alteromonas/química , Metais Pesados/metabolismo , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/farmacologia , Adsorção , Água do Mar/microbiologia
7.
J Cosmet Sci ; 68(1): 126-132, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29465393

RESUMO

Through natural selection, living organisms have evolved well-adapted survival strategies over time. The shallow salt waters of Moorea lagoon are the site of accumulation of microbial mats called "Kopara," in the native Polynesian language. This unique ecosystem is rich in film-forming exopolysaccharides (EPSs) secreted by microorganisms within the biofilm, as a mean to protect themselves from environmental stress (strong ultraviolet [UV], pH, salinity … ). Using blue biotechnology, a manufacturing process was developed to obtain an EPS with skin benefits. The active ingredient (EPS-229) protects against urban pollution, including free radicals, heavy metals, hydrocarbons, and PM2.5 (particulate matter with a size lower than 2.5 µm). METHODS: The anti-lipid peroxidation action of EPS-229 was studied in an in vitro UVB-irradiated keratinocyte culture model, using lipophilic fluorescent probe. The chelating properties of EPS-229 were evaluated in tubo in the presence of cadmium and lead. The protective effect of EPS-229 on pollution-exposed skin explants was investigated through quantification of released malondialdehyde (MDA) and histological observation of skin morphology using optical microscopy. Clinical evaluation of the protective and cleansing efficacy of a water solution containing EPS-229 (0.02% and 0.01% w/v, respectively) was performed, against placebo, on a panel of 18 volunteers. For these studies, the forearms of volunteers were treated with EPS-229 before (anti-adhesion affect) or after (cleansing effect) application of PM2.5 (iron particles of 1 µm). The presence of skin-adherent particles was observed and quantified by image analysis, using specific digital masks. RESULTS: In vitro, EPS-229 significantly protected keratinocyte cell membranes from lipid peroxidation. A decrease of 28% was achieved when a concentration of 0.001% w/v EPS-229 was applied to the cell culture. In tubo, EPS-229 also presented strong chelating properties. Maximal adsorption was estimated at 154 mg/g (1.37 mmol/g) of EPS-299 for cadmium and at 250 mg/g (1.21 mmol/g) of EPS-229 for lead. In the skin explant model of pollution exposure, EPS-229 (0.03% w/v) reduced MDA production by 44%, preserved cell integrity, improved dermal-epidermal cohesion, and normalized the collagen network. In vivo, treatment of skin with EPS-229 before exposure to PM2.5 created a protective film limiting particle adhesion. When used in a cleansing solution after exposure to PM2.5, EPS-229 formed a mesh that entrapped particles and removed them from the skin surface. CONCLUSION: Inspired by the French Polynesia Kopara unique ecosystem, a bioactive exopolysaccharide (EPS-229) has been developed that offers protection from environmental aggression. As a biomimetic shield at the surface of the skin, EPS-229 provides an immediate multiprotective action that efficiently fights the harmful effects of urban pollution and smog.


Assuntos
Biomimética , Poluentes Ambientais/efeitos adversos , Polissacarídeos/farmacologia , Substâncias Protetoras/farmacologia , Pele/efeitos dos fármacos , Alteromonas/química , Alteromonas/metabolismo , Fármacos Dermatológicos/química , Fármacos Dermatológicos/farmacologia , Fermentação , Radicais Livres/efeitos adversos , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Metais Pesados/toxicidade , Higiene da Pele , Saúde da População Urbana
8.
J Hazard Mater ; 318: 443-451, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27450336

RESUMO

In this study, we investigated the effects of a symbiotic bacterium and phosphate (PO4(3-)) nutrition on the toxicity and metabolism of arsenate (As(V)) in Dunaliella salina. The bacterium was identified as Alteromonas macleodii based on analysis of its 16S rRNA gene sequence. When no As(V) was added, A. macleodii significantly enhanced the growth of D. salina, irrespective of PO4(3-) nutrition levels, but this effect was reversed after As(V)+PO4(3-) treatment (1.12mgL(-1)) for 3 days. Arsenic (As) absorption by the non-axenic D. salina was significantly higher than that by its axenic counterpart during incubation with 1.12mgL(-1) PO4(3-). However, when the culture was treated with 0.112mgL(-1) PO4(3-), As(V) reduction and its subsequent arsenite (As(III)) excretion by non-axenic D. salina were remarkably enhanced, which, in turn, contributed to lower As absorption in non-axenic algal cells from days 7 to 9. Moreover, dimethylarsinic acid was synthesized by D. salina alone, and the rates of its production and excretion were accelerated when the PO4(3-) concentration was 0.112mgL(-1). Our data demonstrate that A. macleodii strongly affected As toxicity, uptake, and speciation in D. salina, and these impacts were mediated by PO4(3-) in the cultures.


Assuntos
Alteromonas/metabolismo , Arseniatos/metabolismo , Clorófitas/metabolismo , Alteromonas/química , Arseniatos/toxicidade , Biotransformação , Clorófitas/classificação , Clorófitas/efeitos dos fármacos , Meios de Cultura , Fosfatos/farmacologia , Simbiose
9.
Mikrobiol Z ; 77(5): 47-54, 2015.
Artigo em Russo | MEDLINE | ID: mdl-26638484

RESUMO

Alteromonas macleodii strains isolated from the Black sea water were similar in their fatty acids composition with the type strain of this species. Analysis of lipid composition of 10 A. macleodii strains isolated from the deep and surface water layers in different World ocean regions including the Black sea water has shown that the deep and surface isolates of this species formed two groups different in their fatty acids profiles. The Black sea isolates of Pseudoalteromonas haloplanktis, P. citrea, P. flavipulchra conformed to these species type strains in their fatty acids composition. On the basis of the fatty acids spectra similarity of three Pseudoalteromonas species strains with Plipolytica described in 2010 has been established. Presence of three isomers C16:1ψ7, C 16:1ψ9 and C16:1ψ6--components of hexadecenic acid in the Black sea isolates of Shewanella baltica has been shown.


Assuntos
Alteromonas/química , Ácidos Graxos/análise , Água do Mar/microbiologia , Alteromonas/classificação , Alteromonas/isolamento & purificação , Mar Negro , Especificidade da Espécie , Ucrânia
10.
PLoS One ; 10(11): e0142690, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26571122

RESUMO

Most marine bacteria produce exopolysaccharides (EPS), and bacterial EPS represent an important source of dissolved organic carbon in marine ecosystems. It was proposed that bacterial EPS rich in uronic acid is resistant to mineralization by microbes and thus has a long residence time in global oceans. To confirm this hypothesis, bacterial EPS rich in galacturonic acid was isolated from Alteromonas sp. JL2810. The EPS was used to amend natural seawater to investigate the bioavailability of this EPS by native populations, in the presence and absence of ammonium and phosphate amendment. The data indicated that the bacterial EPS could not be completely consumed during the cultivation period and that the bioavailability of EPS was not only determined by its intrinsic properties, but was also determined by other factors such as the availability of inorganic nutrients. During the experiment, the humic-like component of fluorescent dissolved organic matter (FDOM) was freshly produced. Bacterial community structure analysis indicated that the class Flavobacteria of the phylum Bacteroidetes was the major contributor for the utilization of EPS. This report is the first to indicate that Flavobacteria are a major contributor to bacterial EPS degradation. The fraction of EPS that could not be completely utilized and the FDOM (e.g., humic acid-like substances) produced de novo may be refractory and may contribute to the carbon storage in the oceans.


Assuntos
Alteromonas/química , Consórcios Microbianos , Polissacarídeos Bacterianos/química , Água do Mar/microbiologia , Microbiologia da Água , Compostos de Amônio/química , Bacteroidetes , Carbono/química , China , DNA Ribossômico/genética , Ecossistema , Glucose/química , Ácidos Hexurônicos/química , Substâncias Húmicas , Hidrólise , Peso Molecular , Oceanos e Mares , Fosfatos/química , RNA Ribossômico 16S/genética , Espectrometria de Fluorescência , Ácidos Urônicos/química
11.
Biochemistry ; 54(41): 6423-33, 2015 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-26418828

RESUMO

The enzyme organophosphorus acid anhydrolase (OPAA), from Alteromonas sp. JD6.5, has been shown to rapidly catalyze the hydrolysis of a number of toxic organophosphorus compounds, including several G-type chemical nerve agents. The enzyme was cloned into Escherichia coli and can be produced up to approximately 50% of cellular protein. There have been no previous reports of OPAA activity on VR {Russian VX, O-isobutyl S-[2-(diethylamino)ethyl] methylphosphonothioate}, and our studies reported here show that wild-type OPAA has poor catalytic efficacy toward VR. However, via application of a structurally aided protein engineering approach, significant improvements in catalytic efficiency were realized via optimization of the small pocket within the OPAA's substrate-binding site. This optimization involved alterations at only three amino acid sites resulting in a 30-fold increase in catalytic efficiency toward racemic VR, with a strong stereospecificity toward the P(+) enantiomer. X-ray structures of this mutant as well as one of its predecessors provide potential structural rationales for their effect on the OPAA active site. Additionally, a fourth mutation at a site near the small pocket was found to relax the stereospecificity of the OPAA enzyme. Thus, it allows the altered enzyme to effectively process both VR enantiomers and should be a useful genetic background in which to seek further improvements in OPAA VR activity.


Assuntos
Alteromonas/enzimologia , Alteromonas/genética , Arildialquilfosfatase/genética , Arildialquilfosfatase/metabolismo , Compostos Organotiofosforados/metabolismo , Alteromonas/química , Alteromonas/metabolismo , Arildialquilfosfatase/química , Domínio Catalítico , Clonagem Molecular , Cristalografia por Raios X , Escherichia coli/genética , Hidrólise , Modelos Moleculares , Mutagênese Sítio-Dirigida , Conformação Proteica , Engenharia de Proteínas , Estereoisomerismo , Especificidade por Substrato
12.
Biomed Res Int ; 2015: 508656, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26090416

RESUMO

GY785 is an exopolysaccharide produced by a mesophilic bacterial strain Alteromonas infernus discovered in the deep-sea hydrothermal vents. GY785 highly sulfated derivative (GY785 DRS) was previously demonstrated to be a promising molecule driving the efficient mesenchymal stem cell chondrogenesis for cartilage repair. This glycosaminoglycan- (GAG-) like compound was modified in a classical solvent (N,N'-dimethylformamide). However, the use of classical solvents limits the polysaccharide solubility and causes the backbone degradation. In the present study, a one-step efficient sulfation process devoid of side effects (e.g., polysaccharide depolymerization and/or degradation) was developed to produce GAG-like derivatives. The sulfation of GY785 derivative (GY785 DR) was carried out using ionic liquid as a reaction medium. The successful sulfation of this anionic and highly branched heteropolysaccharide performed in ionic liquid would facilitate the production of new molecules of high specificity for biological targets such as tissue engineering or regenerative medicine.


Assuntos
Condrogênese/efeitos dos fármacos , Líquidos Iônicos/administração & dosagem , Células-Tronco Mesenquimais/efeitos dos fármacos , Polissacarídeos/administração & dosagem , Alteromonas/química , Organismos Aquáticos/química , Líquidos Iônicos/química , Polissacarídeos/química , Medicina Regenerativa , Sulfatos/química , Engenharia Tecidual
13.
ACS Chem Biol ; 10(7): 1684-93, 2015 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-25856271

RESUMO

Within a superfamily, functionally diverged metalloenzymes often favor different metals as cofactors for catalysis. One hypothesis is that incorporation of alternative metals expands the catalytic repertoire of metalloenzymes and provides evolutionary springboards toward new catalytic functions. However, there is little experimental evidence that incorporation of alternative metals changes the activity profile of metalloenzymes. Here, we systematically investigate how metals alter the activity profiles of five functionally diverged enzymes of the metallo-ß-lactamase (MBL) superfamily. Each enzyme was reconstituted in vitro with six different metals, Cd(2+), Co(2+), Fe(2+), Mn(2+), Ni(2+), and Zn(2+), and assayed against eight catalytically distinct hydrolytic reactions (representing native functions of MBL enzymes). We reveal that each enzyme metal isoform has a significantly different activity level for native and promiscuous reactions. Moreover, metal preferences for native versus promiscuous activities are not correlated and, in some cases, are mutually exclusive; only particular metal isoforms disclose cryptic promiscuous activities but often at the expense of the native activity. For example, the L1 B3 ß-lactamase displays a 1000-fold catalytic preference for Zn(2+) over Ni(2+) for its native activity but exhibits promiscuous thioester, phosphodiester, phosphotriester, and lactonase activity only with Ni(2+). Furthermore, we find that the five MBL enzymes exist as an ensemble of various metal isoforms in vivo, and this heterogeneity results in an expanded activity profile compared to a single metal isoform. Our study suggests that promiscuous activities of metalloenzymes can stem from an ensemble of metal isoforms in the cell, which could facilitate the functional divergence of metalloenzymes.


Assuntos
Alteromonas/enzimologia , Escherichia coli/enzimologia , Metais/metabolismo , Pseudomonas aeruginosa/enzimologia , Salmonella/enzimologia , beta-Lactamases/metabolismo , Alteromonas/química , Escherichia coli/química , Hidrólise , Metais/química , Modelos Moleculares , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismo , Pseudomonas aeruginosa/química , Salmonella/química , beta-Lactamases/química
14.
PLoS One ; 9(6): e98798, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24932690

RESUMO

The present study demonstrates exopolysaccharide production by an osmotolerant marine isolate and also describes further application of the purified polysaccharide for production of colloidal suspension of silver nanoparticles with narrow size distribution. Phylogenetic analysis based on 16S r RNA gene sequencing revealed close affinity of the isolate to Alteromonas macleodii. Unlike earlier reports, where glucose was used as the carbon source, lactose was found to be the most suitable substrate for polysaccharide production. The strain was capable of producing 23.4 gl(-1) exopolysaccharide with a productivity of 7.8 gl(-1) day(-1) when 15% (w/v) lactose was used as carbon source. Furthermore, the purified polysaccharide was able to produce spherical shaped silver nanoparticles of around 70 nm size as characterized by Uv-vis spectroscopy, Dynamic light scattering and Transmission electron microscopy. These observations suggested possible commercial potential of the isolated strain for production of a polysaccharide which has the capability of synthesizing biocompatible metal nanoparticle.


Assuntos
Alteromonas/isolamento & purificação , Nanopartículas Metálicas/química , Polissacarídeos Bacterianos/biossíntese , Prata/metabolismo , Alteromonas/química , Alteromonas/metabolismo , Microscopia Eletrônica de Transmissão e Varredura , Tamanho da Partícula , Filogenia , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de RNA , Prata/química
15.
Antonie Van Leeuwenhoek ; 103(2): 265-75, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22965754

RESUMO

Bacteria of the genus Alteromonas are Gram-negative, strictly aerobic, motile, heterotrophic marine bacteria known for their versatile metabolic activities. Identification and classification of novel species belonging to the genus Alteromonas generally involves DNA-DNA hybridization (DDH) as distinct species often fail to be resolved at the 97 % threshold value of the 16S rRNA gene sequence similarity. In this study, the applicability of Multilocus Phylogenetic Analysis (MLPA) and Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) for the differentiation of Alteromonas species has been evaluated. Phylogenetic analysis incorporating five house-keeping genes (dnaK, sucC, rpoB, gyrB, and rpoD) revealed a threshold value of 98.9 % that could be considered as the species cut-off value for the delineation of Alteromonas spp. MALDI-TOF MS data analysis reconfirmed the Alteromonas species clustering. MLPA and MALDI-TOF MS both generated data that were comparable to that of the 16S rRNA gene sequence analysis and may be considered as useful complementary techniques for the description of new Alteromonas species.


Assuntos
Alteromonas/classificação , Alteromonas/genética , DNA Bacteriano/química , DNA Bacteriano/genética , Filogenia , Análise de Sequência de DNA/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Alteromonas/química , Análise por Conglomerados , Genes Essenciais , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , RNA Ribossômico 16S/genética
16.
Microb Ecol ; 65(3): 720-30, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23269455

RESUMO

Biodiversity estimates based on ribosomal operon sequence diversity rely on the premise that a sequence is characteristic of a single specific taxon or operational taxonomic unit (OTU). Here, we have studied the sequence diversity of 14 ribosomal RNA operons (rrn) contained in the genomes of two isolates (five operons in each genome) and four metagenomic fosmids, all from the same seawater sample. Complete sequencing of the isolate genomes and the fosmids establish that they represent strains of the same species, Alteromonas macleodii, with average nucleotide identity (ANI) values >97 %. Nonetheless, we observed high levels of intragenomic heterogeneity (i.e., variability between operons of a single genome) affecting multiple regions of the 16S and 23S rRNA genes as well as the internally transcribed spacer 1 (ITS-1) region. Furthermore, the ribosomal operons exhibited intergenomic heterogeneity (i.e., variability between operons located in separate genomes) in each of these regions, compounding the variability. Our data reveal the extensive heterogeneity observed in natural populations of A. macleodii at a single point in time and support the idea that distinct lineages of A. macleodii exist in the deep Mediterranean. These findings highlight the potential of rRNA fingerprinting methods to misrepresent species diversity while simultaneously failing to recognize the ecological significance of individual strains.


Assuntos
Alteromonas/genética , DNA Espaçador Ribossômico/genética , Variação Genética , Óperon , RNA Ribossômico/genética , Água do Mar/microbiologia , Alteromonas/química , Alteromonas/classificação , Alteromonas/isolamento & purificação , Sequência de Bases , Biodiversidade , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Espaçador Ribossômico/química , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Filogenia , RNA Ribossômico/química
17.
J Microbiol Biotechnol ; 22(12): 1621-8, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23221523

RESUMO

The agar-degrading bacterium GNUM-1 was isolated from the brown algal species Sargassum serratifolium, which was obtained from the West Sea of Korea, by using the selective artificial seawater agar plate. The cells were Gram-negative, 0.5-0.6 micrometer wide and 2.0-2.5 micrometer long curved rods with a single polar flagellum, forming nonpigmented, circular, smooth colonies. Cells grew at 20 degrees C- 37 degrees C, between pH 5.0 and 9.0, and at 1-10% (w/v) NaCl. The DNA G+C content of the GNUM-1 strain was 45.5 mol%. The 16S rRNA sequence of the GNUM-1 was very similar to those of Alteromonas stellipolaris LMG 21861 (99.86% sequence homology) and Alteromonas addita R10SW13 T (99.64% sequence homology), which led us to assign it to the genus Alteromonas. It showed positive activities for agarase, amylase, gelatinase, alkaline phosphatase, esterase (C8), lipase (C14), leucine arylamidase, valine arylamidase, alpha-chymotrypsin, acid phosphatase, naphthol- AS-BI-phosphohydrolase, alpha-galactosidase, beta-galactosidase, beta-glucosidase, catalase, and urease. It can utilize citrate, malic acid, and trisodium citrate. The major fatty acids were summed feature 3 (21.5%, comprising C16:1omega7c/iso- C15:0 2-OH) and C16:0 (15.04%). On the basis of the variations in many biochemical characteristics, GNUM-1 was considered as unique and thus was named Alteromonas sp. GNUM-1. It produced the highest agarase activity in modified ASW medium containing 0.4% sucrose, but lower activity in rich media despite superior growth, implying that agarase production is tightly regulated and repressed in a rich nutrient condition. The 30 kDa protein with agarase activity was identified by zymography, and this report serves as the very first account of such a protein in the genus Alteromonas.


Assuntos
Alteromonas/enzimologia , Alteromonas/isolamento & purificação , Glicosídeo Hidrolases/biossíntese , Ágar/metabolismo , Alteromonas/química , Alteromonas/genética , Contagem de Células , Meios de Cultura , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/isolamento & purificação , Glicosídeo Hidrolases/metabolismo , Concentração de Íons de Hidrogênio , Coreia (Geográfico) , Dados de Sequência Molecular , Fenótipo , Filogenia , Sargassum/microbiologia , Cloreto de Sódio , Microbiologia da Água
18.
Biosci Biotechnol Biochem ; 76(8): 1452-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22878186

RESUMO

The KNS-16 algicidal strain was isolated from a harmful alga bloom (HAB) area and identified as Alteromonas sp. based on 16S rDNA sequencing. The KNS-16 strain was found to control HABs by producing algicidal compounds in an indirect interaction. Four active compounds were isolated from KNS-16 culture, and their structures were analyzed by interpreting nuclear magnetic resonance and mass spectroscopy data. The structures were identified as 2-undecen-1'-yl-4-quinolone (1), 2-undecyl-4-quinolone (2), 3-hexyl-6-pentyl-4-hydroxyl-2H-pyran-2-one (3), and 6-heptyl-3-hexyl-4-hydroxyl-2H-pyran-2-one (4). Compound 1 was most active against HABs such as Heterosigma akashiwo, Cochlodinium polykrikoides, and Alexandrium tamarense with LC(50) values of 0.5-1.1 µg/mL. The four compounds exhibited high LC(50) values against aquaculture algae such as Tetaselmis suecica, Isochrysis galbana, and Pavlova lutheri at 39-66 µg/mL. Based on toxicity tests on the brine shrimp Artemia salina and the rotifer Brachionus rotundiformis, the four compounds showed ranges of 409-608 and 189-224 µg/mL of LC(50) for the two organisms, respectively. The LC(50) values for juvenile fish of Sebastes schlegelii were 284-304 µg/mL.


Assuntos
Alteromonas/química , Proliferação Nociva de Algas/efeitos dos fármacos , Lactonas/farmacologia , Pironas/farmacologia , Quinolonas/farmacologia , RNA Ribossômico 16S/genética , Alteromonas/genética , Proliferação Nociva de Algas/fisiologia , Concentração Inibidora 50 , Lactonas/química , Lactonas/isolamento & purificação , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Pironas/química , Pironas/isolamento & purificação , Quinolonas/química , Quinolonas/isolamento & purificação , Análise de Sequência de DNA
19.
J Gen Appl Microbiol ; 58(2): 129-35, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22688244

RESUMO

The phenotypic, chemotaxonomic and genetic peculiarities of 5 deep strains of Alteromonas macleodii (isolated from Adriatic and Ionian Sea water from a depth of 1,000-3,500 m) and 5 strains of the same species isolated from the surface layer of Aegean, Andaman, Black Sea and Atlantic Ocean water near the British shore have been studied. Electron microscopy has shown that the deep strains' cells were, on average, two times longer (2.1±0.2×0.7±0.1 µm) than the surface strains' (1.1±0.1×0.6±0.1 µm). Using fatty acid analysis (particularly the mono-unsaturated C16:1 and C18:1 fatty acids contents) the deep and surface isolates were clearly separated into two clusters. Distinctions between them were also found in different lectin binding capacity, which is probably determined by the structure of their extracellular polysaccharide matrix. Analysis of the results of PCR with primers to repeated nucleotide sequences revealed a higher level of genetic polymorphism in surface strains in comparison with the deep isolates. This division was confirmed by the cluster analysis method though it was not as clear as in the fatty acids analysis. The described peculiarities are probably reflective of specific conditions in which A. macleodii strains live on the surface or in the depth of the world's oceans.


Assuntos
Alteromonas/classificação , Alteromonas/fisiologia , Ecossistema , Água do Mar/microbiologia , Alteromonas/química , Alteromonas/genética , Técnicas de Tipagem Bacteriana , Análise por Conglomerados , Ácidos Graxos/análise , Genética Populacional , Microscopia Eletrônica , Oceanos e Mares , Fenótipo , Reação em Cadeia da Polimerase , Polimorfismo Genético , Polissacarídeos/análise
20.
Carbohydr Polym ; 90(1): 49-59, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-24751009

RESUMO

Some marine bacteria collected around deep-sea hydrothermal vents are able to produce, in laboratory conditions, complex and innovative exopolysaccharides. In a previous study, the mesophilic strain Alteromonas macleodii subsp. fijiensis biovar deepsane was collected on the East Pacific Rise at 2600 m depth. It was isolated from a polychaete annelid Alvinella pompejana and is able to synthesise and excrete the exopolysaccharide deepsane. Biological activities have been screened and some protective properties have been established. Deepsane is commercially available in cosmetics under the name of Abyssine(®) for soothing and reducing irritation of sensitive skin against chemical, mechanical and UVB aggression. This study presents structural data for this original and complex bacterial exopolysaccharide and highlights some structural similarities with other known EPS produced by marine Alteromonas strains.


Assuntos
Alteromonas/química , Polissacarídeos Bacterianos/química , Sequência de Carboidratos , Metilação , Monossacarídeos/análise , Monossacarídeos/isolamento & purificação , Ressonância Magnética Nuclear Biomolecular , Oligossacarídeos/análise , Oligossacarídeos/isolamento & purificação , Polissacarídeos Bacterianos/isolamento & purificação , Espectrometria de Massas por Ionização por Electrospray
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