Sabiia Seb
PortuguêsEspañolEnglish
Embrapa
        Busca avançada

Botão Atualizar


Botão Atualizar

Ordenar por: RelevânciaAutorTítuloAnoImprime registros no formato resumido
Registros recuperados: 19
Primeira ... 1 ... Última
Imagem não selecionada

Imprime registro no formato completo
A biofilm-forming marine bacterium producing proteins as extracellular polymeric substances ArchiMer
Leroy, Celine; Delbarre Ladrat, Christine; Ghillebaert, François; Compere, Chantal; Combes, Didier.
EPS biochemical characterization and observation by epifluorescencemicroscopy. Development of a marine biofilmformation model onto a polystyrene microtiterplate using the “O’Tooleand Koltermethod”[1] adapted with the well known fluorescent DNA staining DAPI
Tipo: Text
Ano: 2005 URL: http://archimer.ifremer.fr/doc/00089/19998/17661.pdf
Imagem não selecionada

Imprime registro no formato completo
A marine bacterial adhesion microplate test using the DAPI fluorescent dye: a new method to screen antifouling agents ArchiMer
Leroy, Celine; Delbarre Ladrat, Christine; Ghillebaert, F; Rochet, Marie-joelle; Compere, Chantal; Combes, D.
Aims: To develop a method to screen antifouling agents against marine bacterial adhesion as a sensitive, rapid, quantitative microplate fluorescent test. Methods and Results: Our experimental method is based on a natural biofilm formed by mono-incubation of the marine bacterium Pseudoalteromonas sp. D41 in sterile natural sea water in a 96 wells polystyrene microplate. The 4'6-diamidino-2-phenylindole (DAPI) dye was used to quantify adhered bacteria in each well. Total measured fluorescence in wells was correlated with the amount of bacteria showing a detection limit of one bacterium per 5 µm2 and quantifying 2 x 107 to 2 x 108 bacteria adhered per cm2. The antifouling properties of three commercial surface active agents and chlorine were tested by this...
Tipo: Text Palavras-chave: Antifouling; Pseudoalteromonas; Screening; Microtiter plate; Adhesion; DAPI; Marine biofilm.
Ano: 2007 URL: http://archimer.ifremer.fr/doc/2006/publication-2017.pdf
Imagem não selecionada

Imprime registro no formato completo
Adhésion et substances polymériques extracellulaires d’une nouvelle espèce bactérienne marine ArchiMer
Leroy, Celine; Compere, Chantal; Delbarre Ladrat, Christine; Raguenes, Gerard; Ghillebaert, François; Combes, Didier.
Une nouvelle bactérie marine du genre Pseudoalteromonas sp., D41, formant rapidement des biofilms sur tout type de matériau (verre, acier inoxydable, Téflon) a été isolée en Baie de Brest. L’objectif de ce présent travail est de caractériser et décrire cette bactérie capable de produire des exopolymères constitués en majorité de protéines. Le rôle des protéines sécrétées, dans les mécanismes d’adhésion, est discuté.
Tipo: Text
Ano: 2005 URL: http://archimer.ifremer.fr/doc/00088/19950/17617.pdf
Imagem não selecionada

Imprime registro no formato completo
Assessment of biochemical methods to detect enzymatic depolymerization of polysaccharides ArchiMer
Rigouin, Coraline; Delbarre Ladrat, Christine; Sinquin, Corinne; Colliec-jouault, Sylvia; Dion, M.
To find biocatalyst allowing depolymerization of new polysaccharides, one needs to get a sensitive and well adapted method to a screening program. This led us to compare biochemical methods of detection of the depolymerization. Currently used methods such as reducing sugars assays, double bond monitoring or molecular weight determination were tested to follow the kinetic of depolymerization with different enzyme / polysaccharide couples. The range of concentrations of assorted enzymes allowed us to identify the most sensitive and appropriate method to detect polysaccharide degradation. Reducing sugars assays are quantitative, sensitive and almost usable with all kind of polysaccharide but some compounds may interfere with them. When polysaccharide is...
Tipo: Text Palavras-chave: Detection; Enzyme; Depolymerization; Carbohydrate.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/2008/publication-4723.pdf
Imagem não selecionada

Imprime registro no formato completo
Calpain and cathepsin activities in post mortem fish and meat muscles ArchiMer
Cheret, Romuald; Delbarre Ladrat, Christine; De Lamballerie Anton, Marie; Verrez-bagnis, Veronique.
Post mortem tenderization is one of the most unfavourable quality changes in fish muscle and this contrasts with muscle of mammalian meats. The tenderization can be partly attributed to the acid lysosomal cathepsins and cytosolic neutral calcium-activated calpains. In this study, these proteases from fish and bovine muscles were quantified and compared. The cathepsin B and L activities were in more important amounts in sea bass white muscle than in bovine muscle. On the other hand, cathepsin D activity was 1.4 times higher in meat that in fish muscle, while cathepsin H was negligible in both muscles. Calpain activities were similar in both types of muscle. Moreover, calpastatin (calpain endogenous inhibitor) level is 3.9 times higher in sea bass white...
Tipo: Text Palavras-chave: Meat; Fish; Protease; Cathepsin; Calpain.
Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/publication-3646.pdf
Imagem não selecionada

Imprime registro no formato completo
Characterization of biofilm extracts from two marine bacteria ArchiMer
Passerini, Delphine; Fecamp, Florian; Marchand, Laetitia; Kolypczuk, Laetitia; Bonnetot, Sandrine; Sinquin, Corinne; Verrez-bagnis, Veronique; Hervio Heath, Dominique; Colliec Jouault, Sylvia; Delbarre Ladrat, Christine.
In the marine environment, biofilm formation is an important lifestyle for microorganisms. A biofilm is comprised of cells embedded in an extracellular matrix that holds them close together and keeps the biofilm attached to the colonized surface. This predominant lifestyle and its main regulation pathway, namely quorum-sensing (QS), have been shown to induce specific bioactive metabolites. In this study, we investigated the biofilm formation by two marine bacteria belonging to the Vibrio species to discover potentially innovative bioactive compounds. We proposed a protocol to isolate biofilm extracts, to analyze their biochemical composition, and to compare them to planktonic cell extracts. Cells were grown attached to a plastic surface; extracts were...
Tipo: Text Palavras-chave: Vibrio; Biofilm; Polysaccharide; Quorum-sensing; Activity.
Ano: 2019 URL: https://archimer.ifremer.fr/doc/00592/70381/68461.pdf
Imagem não selecionada

Imprime registro no formato completo
Characterization of New Oligosaccharides Obtained by An Enzymatic Cleavage of the Exopolysaccharide Produced by the Deep-Sea Bacterium Alteromonas infernus Using its Cell Extract ArchiMer
Akoumany, Katy; Zykwinska, Agata; Sinquin, Corinne; Marchand, Laetitia; Fanuel, Mathieu; Ropartz, David; Rogniaux, Hélène; Pipelier, Muriel; Delbarre Ladrat, Christine; Colliec Jouault, Sylvia.
Bacteria from deep-sea hydrothermal vents constitute an attractive source of bioactive molecules. In particular, exopolysaccharides (EPS) produced by these bacteria become a renewable source of both biocompatible and biodegradable molecules. The low molecular weight (LMW) derivatives of the GY785 EPS produced by the deep-sea hydrothermal vent strain Alteromonas infernus have previously displayed some biological properties, similar to those of glycosaminoglycans (GAG), explored in cancer and tissue engineering. These GAG-mimetic derivatives are obtained through a free radical depolymerization process, which could, however, affect their structural integrity. In a previous study, we have shown that A. infernus produces depolymerizing enzymes active on its own...
Tipo: Text Palavras-chave: Deep-sea bacterium; Alteromonas infernus; Wild-type strain; Exopolysaccharides; Glycosaminoglycan-mimetic; Enzymatic depolymerization; Structural analysis; Mass spectrometry.
Ano: 2019 URL: https://archimer.ifremer.fr/doc/00515/62644/67021.pdf
Imagem não selecionada

Imprime registro no formato completo
Comparative genomics reveals a widespread distribution of an exopolysaccharide biosynthesis gene cluster among Vibrionaceae ArchiMer
Lebellenger, Lou; Verrez-bagnis, Veronique; Passerini, Delphine; Delbarre Ladrat, Christine.
Objectives The eps locus in Vibrio diabolicus is involved in the production of the biotechnologically valuable HE800 EPS. In this study, the distribution and diversity of similar eps gene clusters across Vibrionaceae and its variability in relation to phylogenetic relationship were investigated. The aim was to provide a better knowledge of the eps gene cluster importance and to facilitate discovery of new EPS with potent interesting bioactivities. Results Seventy percent of the 103 genome sequences examined display such an eps locus with a high level of synteny. However, genetic divergence was found inside some monophyletic clades or even between some strains of the same species. It includes gene insertions, truncations, and deletions. Comparative analysis...
Tipo: Text Palavras-chave: Vibrionaceae; Exopolysaccharide; Genetic biodiversity; Biosynthesis; Vibrio diabolicus; HE800 EPS.
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00424/53536/54392.pdf
Imagem não selecionada

Imprime registro no formato completo
Effect of high pressure on the calpain-calpastatin system in fish muscle ArchiMer
Cheret, Romuald; Delbarre Ladrat, Christine; Verrez-bagnis, Veronique; De Lamballerie, Marie.
Calpains (calcium-activated neutral proteases) of sea bass (Dicentrarchus labrax L.) muscle may participate in the degradation of muscle tissue during postmortem storage. These enzymes are regulated by calpastatin, their endogenous specific inhibitor. The objective of this study was to evaluate the changes encountered by the calpain system during the postmortem storage of fish muscle after high-pressure treatment. From 100 MPa, high-pressure treatment of purified calpains results in a loss of their activity as well as in the dissociation of the heterodimeric form. In muscle, the high-pressure processing decreases the initial activity of calpain. This loss in activity may be due to an inactivation by a change of structure. Initial calpastatin activity is...
Tipo: Text Palavras-chave: Postmortem denaturation; High pressure; Fish; Calpain system.
Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/publication-2786.pdf
Imagem não selecionada

Imprime registro no formato completo
Effects of commercial enzymes on the adhesion of a marine biofilm-forming bacterium ArchiMer
Leroy, C.; Delbarre Ladrat, Christine; Ghillebaert, F.; Compere, Chantal; Combes, D..
The antifouling potential of commercial hydrolases, four proteases, seven glycosidases and one lipase was evaluated on the adhesion of marine Pseudoalteromonas sp. D41. The experimental method, adapted to screen antifouling agents, was based on bacterial adhesion in natural sterile sea water in a microtiter plate and on total biomass quantification by the fluorescent dye DAPI (4[prime]6-diamidino-2-phenylindole). Savinase (subtilisin) was the most effective hydrolase in both the prevention of bacterial adhesion and the removal of adhered bacteria. However, some enzymatic preparations tested such as Amano protease were not only ineffective but also increased the number of adhered bacterial cells. Enumeration using epifluorescence microscopy of CTC...
Tipo: Text Palavras-chave: Marine biofilm; Antifouling; Pseudoalteromonas; Enzymes; Adhesion.
Ano: 2008 URL: http://archimer.ifremer.fr/doc/2008/publication-6140.pdf
Imagem não selecionada

Imprime registro no formato completo
Effects of high pressure on texture and microstructure of sea bass (Dicentrarchus labrax L.) fillets ArchiMer
Cheret, Romuald; Chapleau, Nicolas; Delbarre Ladrat, Christine; Verrez-bagnis, Veronique; De Lamballerie, Marie.
High pressure is an innovative non-thermal food-preservation technology. We studied the effect of high-pressure treatment up-to 500 MPa for 5 min on physical characteristics of sea bass fillets after 0, 7, and 14 d of refrigerated storage.. Color results exhibited an increase of lightness and a slight change of hue, which might be imperceptible in cooked fish. High-pressure treatment induced a decrease of exudation and water-holding capacity Pressure treatment above 300 MPa provoked higher fish hardness after storage than in untreated sample, proving the ability of high pressure to improve textural, quality of chilled, stored fish fillet. These assessments were corroborated with microstructure observations. We showed that high-pressure treatment at 500 MPa...
Tipo: Text Palavras-chave: Preservation; Microstructure; Texture profile analysis; High pressure; Fish.
Ano: 2005 URL: http://archimer.ifremer.fr/doc/2005/publication-734.pdf
Imagem não selecionada

Imprime registro no formato completo
In vitro proteolysis of myofibrillar and sarcoplasmic proteins of European sea bass (Dicentrarchus Labrax L) by an endogenous m-calpain ArchiMer
Verrez-bagnis, Veronique; Delbarre Ladrat, Christine; Noel, Joelle; Fleurence, Joel.
The effects of m-calpain isolated from the skeletal muscle of sea bass on sarcoplasmic and myofibrillar proteins isolated from the same tissue were examined in vitro. Incubation of sarcoplasmic proteins with m-calpain resulted in only a slight decrease (0.7 kDa) in the molecular weight (MW) of a 26.5 kDa protein. Degradation of myofibrils, monitored by quantification of TCA-soluble peptides generated, resulted in the maximum amount of peptides being generated after 1 h of incubation at 25degreesC. Noticeable modifications in the SDS-PAGE profile of digested myofibrils were observed, including partial denaturation of myosin heavy chain and the release of tropomyosin, similar to69 and similar to27 kDa doublet bands and a few polypeptides of MW lower than 20...
Tipo: Text Palavras-chave: Dicentrarchus labrax L; Proteolysis; Sarcoplasmic protein; Calpain; Myofibrillar protein.
Ano: 2002 URL: http://archimer.ifremer.fr/doc/2002/publication-1108.pdf
Imagem não selecionada

Imprime registro no formato completo
In vitro proteolysis of myofibrillar and sarcoplasmic proteins of white muscle of sea bass (Dicentrarchus labrax L.): effects of cathepsins B, D and L ArchiMer
Delbarre Ladrat, Christine; Verrez-bagnis, Veronique; Noel, Joelle; Fleurence, Joel.
The purpose of this study was to obtain additional information regarding proteolysis mechanisms and disorganization of fish myofibrils resulting in a loss of flesh quality. The ability of cathepsins to degrade in vitro myofibrillar and sarcoplasmic proteins from fish muscle was investigated in order to explain their role in post mortem softening. This led to the identification of substrates of the enzymes. Cathepsins degraded myosin heavy chain and a-actinin. Tropomyosin and actin were only susceptible to the action of cathepsin L. Troponin T (assumed 32 kDa component) was resistant only to the action of cathepsin D. Desmin was degraded by cathepsins B and L. Slight changes of some other myofibrillar or cytosolic proteins were also observed (creatine...
Tipo: Text Palavras-chave: Post mortem degradation; Fish muscle proteins; Cathepsins; In vitro proteolysis.
Ano: 2003 URL: http://archimer.ifremer.fr/doc/2003/publication-1684.pdf
Imagem não selecionada

Imprime registro no formato completo
Influence of subtilisin on the adhesion of a marine bacterium which produces mainly proteins as extracellular polymers ArchiMer
Leroy, Celine; Delbarre Ladrat, Christine; Ghillebaert, F; Compere, Chantal; Combes, D.
Aims: The nature of exopolymers involved in the adhesion of a marine biofilm-forming bacterium Pseudoalteromonas sp. D41 was investigated to evaluate and understand the antifouling potential of subtilisin. Methods and Results: The exopolymers of D41 produced by fermentation were analysed by FTIR and SDS-PAGE showing the presence of polysaccharides, glycoproteins and proteins. A high content of proteins was detected both in soluble and capsular fractions. The microscopic observations of fluorescamine and calcofluor stained adhered D41 indicated mainly the presence of proteins in exopolymers produced during adhesion. Subtilisin, the broad spectrum protease, tested in natural sea water and in polystyrene microplates showed that antifouling activity was...
Tipo: Text Palavras-chave: Subtilisin; Pseudoalteromonas; Exopolymer; Capsular protein; Biofilm; Antifouling.
Ano: 2008 URL: http://archimer.ifremer.fr/doc/2008/publication-4624.pdf
Imagem não selecionada

Imprime registro no formato completo
Mining of the biosynthetic mechanisms of Vibrio spp. polysaccharides and potential role in biofilm formation ArchiMer
Verrez-bagnis, Veronique; Soree, Marion; Passerini, Delphine; Kolypczuk, Laetitia; Marchand, Laetitia; Bonnetot, Sandrine; Fecamp, Florian; Lozach, Solen; Hervio Heath, Dominique; Delbarre Ladrat, Christine.
Vibrio spp. are ubiquitous marine bacteria that are ecologically and metabolically diverse members of planktonic and animal associated microbial communities. They encompass the ancient and well-studied human pathogen, Vibrio cholerae, and two other human pathogens, V. vulnificus and V. parahaemolyticus, as well as some less thoroughly characterized animal pathogens. Virulence is based on a wide diversity of mechanisms involved in motility and host colonization, in ability to persist and develop, and in damage generation. Polysaccharides may play major roles in virulence and are major components of extracellular polymeric matrix synthesized upon biofilm growth. They may also exhibit biological features, especially those similar to animal-derived...
Tipo: Text
Ano: 2019 URL: https://archimer.ifremer.fr/doc/00514/62605/66965.pdf
Imagem não selecionada

Imprime registro no formato completo
Proteins and proteolytic activity changes during refrigerated storage in sea bass (Dicentrarchus labrax L.) muscle after high-pressure treatment ArchiMer
Cheret, Romuald; Hernandez Andres, Aránzazu; Delbarre Ladrat, Christine; De Lamballerie, Marie; Verrez-bagnis, Veronique.
Contrary to other preservation methods like thermal treatments, high pressure can destroy microorganisms without affecting the nutritional quality, color, or food texture. The firm texture of fish flesh is an important quality parameter. During the refrigerated storage, the tissue becomes softer and the muscle is deteriorated by different proteases. The aim of this study was to study the modification of the fish muscle proteins after high-pressure treatment during the refrigerated storage and to evaluate the effect of high-pressure treatment level on the post-mortem protein changes and enzyme activities. The calpain activity decreased with the high-pressure treatment and evolved differently during the refrigerated storage, depending on the level of...
Tipo: Text Palavras-chave: Cathepsins; Calpains; Sarcoplasmic proteins; Myofibrillar proteins; Post mortem denaturation; High pressure; Fish.
Ano: 2006 URL: http://archimer.ifremer.fr/doc/2006/publication-1708.pdf
Imagem não selecionada

Imprime registro no formato completo
Proteolytic potential in white muscle of sea bass (Dicentrarchus labrax L.) during post mortem storage on ice: time-dependent changes in the activity of the components of the calpain system ArchiMer
Delbarre Ladrat, Christine; Verrez-bagnis, Veronique; Noel, Joelle; Fleurence, Joel.
The variations in the amounts of milli-calpain and its specific inhibitor in the white muscle of sea bass (Dicentrarchus labrax) during storage at 4 degreesC for up to 7 days were determined after separation by hydrophobic chromatography on a Phenyl Sepharose vel. There was a significant decline in post-slaughter m-calpain activity with an important inter-individual variability in the rate of decrease of the total activity. In contrast with the calpastatin of mammalian post mortem muscles, calpastatin remained constant within fish muscles after death. The initial levels of protease and inhibitor activities, and their behaviour through post mortem storage. are discussed and implications for the mechanism of tenderisation of fish muscle are suggested. (C)...
Tipo: Text Palavras-chave: Proteolysis; Post mortem; Fish muscle; Calpain; Calpastatin; Neutral calcium dependent protease.
Ano: 2004 URL: http://archimer.ifremer.fr/doc/2004/publication-1683.pdf
Imagem não selecionada

Imprime registro no formato completo
Relative contribution of calpain and cathepsins to protein degradation in muscle of sea bass (Dicentrarchus labrax L.) ArchiMer
Delbarre Ladrat, Christine; Verrez-bagnis, Veronique; Noel, Joelle; Fleurence, Joel.
The effects of a milli(m)-calpain isolated from the white muscle of sea bass (Dicentrarchus labrax L) and commercial cathepsins B, D and L, used in combination on the myofibrillar and sarcoplasmic proteins were examined. Protein digestion was first performed by the endogenous m-calpain, (luring 2 h before the addition of a mixture of cathepsins B, D and L and a further incubation up to 22 h. Calpain degraded a 27 kDa sarcoplasmic component as well as myosin heavy chain, a-actinin, desmin and a 32 kDa component from the myofibrillar fraction. A 97 kDa component and the assumed creatine kinase-aldolase doublet were degraded during the incubation of sarcoplasmic proteins with the cathepsin mixture while, among the myofibrillar proteins, myosin, actin,...
Tipo: Text Palavras-chave: Postmortem aging; Fish muscle; Proteolysis; Cathepsins; Neutral calcium dependent protease.
Ano: 2004 URL: http://archimer.ifremer.fr/doc/2004/publication-1682.pdf
Imagem não selecionada

Imprime registro no formato completo
Trends in postmortem aging in fish: Understanding of proteolysis and disorganization of the myofibrillar structure ArchiMer
Delbarre Ladrat, Christine; Cheret, Romuald; Taylor, Romuald; Verrez-bagnis, Veronique.
Introduction : Quality attributes of fish flesh, including food safety, organoleptic features, nutritional quality and aptitude to industrial transformation, influence consumption and acceptability of fish as food. Fish sensorial changes and texture properties are closely linked to freshness. Along with ante mortem muscle biochemistry, postmortem biochemical processes are directly linked to final quality attributes. The understanding of postmortem mechanisms is a prerequisite for an accurate control of the quality of commercialized fish by the identification of objective markers or indicators. Postmortem tenderization is one of the most important quality attributes of fish muscle. Loss of freshness is due to a complex combination of biochemical, chemical...
Tipo: Text Palavras-chave: Indicator; Quality; Proteolysis; Postmortem; Fish muscle.
Ano: 2006 URL: http://archimer.ifremer.fr/doc/2006/publication-1810.pdf
Registros recuperados: 19
Primeira ... 1 ... Última
 

Empresa Brasileira de Pesquisa Agropecuária - Embrapa
Todos os direitos reservados, conforme Lei n° 9.610
Política de Privacidade
Área restrita

Embrapa
Parque Estação Biológica - PqEB s/n°
Brasília, DF - Brasil - CEP 70770-901
Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco

Valid HTML 4.01 Transitional