4 results on '"Holy Ravalason"'
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2. Laccase/HBT and laccase-CBM/HBT treatment of softwood kraft pulp: impact on pulp bleachability and physical properties
- Author
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Jean-Claude Sigoillot, Sacha Grisel, Holy Ravalason, Michel Petit-Conil, Caroline Olivé, Frédérique Bertaud, Katia Ruel, Jean-Paul Joseleau, Isabelle Herpoël-Gimbert, Valérie Meyer, Biodiversité et Biotechnologie Fongiques (BBF), École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Centre Technique du Papier (CTP), Centre de Recherches sur les Macromolécules Végétales (CERMAV), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Biorenew European project: NMP2-CT-2006-026456, Centre Technique du Papier, Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Université Joseph Fourier - Grenoble 1 (UJF)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Ravalason, Holly
- Subjects
0106 biological sciences ,[SDV.SA]Life Sciences [q-bio]/Agricultural sciences ,[SDV.BIO]Life Sciences [q-bio]/Biotechnology ,Heterojunction bipolar transistor ,010501 environmental sciences ,01 natural sciences ,Lignin ,Chlorine dioxide ,chemistry.chemical_compound ,oxygène ,Waste Management and Disposal ,pycnoporus cinnabarinus ,pâte cellulosique ,biology ,Chemistry ,Pulp (paper) ,microscopie électronique ,General Medicine ,blanchiment ,Pulp and paper industry ,Biobleaching ,Pycnoporus ,Agricultural sciences ,traitement enzymatique ,Kraft process ,Aspergillus niger ,Biotechnology ,Paper ,CBM ,Environmental Engineering ,Softwood ,Laccase ,Softwood kraft pulp ,Bioengineering ,Biotechnologies ,engineering.material ,hydroxybenzotriazole ,Industrial Microbiology ,Microscopy, Electron, Transmission ,stomatognathic system ,010608 biotechnology ,Cellulose 1,4-beta-Cellobiosidase ,propriété physique ,Oxygen pressure ,0105 earth and related environmental sciences ,Renewable Energy, Sustainability and the Environment ,Pycnoporus cinnabarinus ,Triazoles ,biology.organism_classification ,pâte kraft ,stomatognathic diseases ,dioxyde de chlore ,engineering ,Sciences agricoles - Abstract
Pycnoporus cinnabarinus laccase and a chimeric laccase-CBM were applied in softwood kraft pulp biobleaching in the presence of 1-hydroxybenzotriazole (HBT). The presence of CBM could enhance the laccase biobleaching potential as a decrease in the enzymatic charge and chlorine dioxide consumption, as well as an increase in pulp brightness were observed. Laccase/HBT treatment could be improved by increasing oxygen pressure from 1 to 3bar and pulp consistency from 5% to 10%. Conversely, under the same conditions, no improvement of laccase-CBM/HBT treatment was observed, indicating a different behavior of both systems. However, laccase-CBM/HBT treatment led to a better preservation of pulp properties. This effect was probably due to fiber surface modifications involving the action of the CBM. Transmission electron microscopy examination of pulp fibers indicated a retention of laccase-CBM inside the pulp fibers due to CBM binding and an increased external microfibrillation of the fibers due to enzymatic treatments.
- Published
- 2012
3. Fusion of a family 1 carbohydrate binding module of Aspergillus niger to the Pycnoporus cinnabarinus laccase for efficient softwood kraft pulp biobleaching
- Author
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Frédérique Bertaud, Cees A. M. J. J. van den Hondel, Michel Petit-Conil, Jean-Claude Sigoillot, Marcel Asther, Holy Ravalason, Isabelle Herpoël-Gimbert, Eric Record, Sacha Grisel, Sandra de Weert, Unité mixte de recherche de biotechnologie des champignons filamenteux, Université de la Méditerranée - Aix-Marseille 2-Institut National de la Recherche Agronomique (INRA)-Université de Provence - Aix-Marseille 1, Centre Technique du Papier (CTP), Universiteit Leiden, Université de Provence - Aix-Marseille 1-Institut National de la Recherche Agronomique (INRA)-Université de la Méditerranée - Aix-Marseille 2, and Leiden University
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Paper ,Softwood ,Recombinant Fusion Proteins ,[SDV]Life Sciences [q-bio] ,Carbohydrates ,Bioengineering ,Applied Microbiology and Biotechnology ,Fungal Proteins ,03 medical and health sciences ,Industrial Microbiology ,LACCASE ,Botany ,BINDING ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,PAPER PULP ,SOFTWOOD KRAFT PULP ,[SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering ,SOFTWOOD ,Cloning, Molecular ,030304 developmental biology ,Laccase ,chemistry.chemical_classification ,0303 health sciences ,biology ,Molecular mass ,ASPERGILLUS NIGER ,030306 microbiology ,Aspergillus niger ,Temperature ,FUNGI ,Oxides ,PYCNOPORUS CINNABARINUS ,General Medicine ,Pycnoporus cinnabarinus ,biology.organism_classification ,Wood ,Pycnoporus ,BIOBLEACHING ,Enzyme ,Kraft process ,Biochemistry ,chemistry ,Carbohydrate Metabolism ,Carbohydrate-binding module ,Chlorine Compounds ,Biotechnology - Abstract
International audience; Pycnoporus cinnabarinus laccase was fused to the C-terminal linker and carbohydrate binding module (CBM) of Aspergillus niger cellobiohydrolase B (CBHB). The chimeric enzyme of molecular mass 100 kDa was successfully produced in A. niger. Laccase-CBM was further purified to determine its main biochemical properties. The Michaelis-Menten constant and pH activity profile were not modified, but the chimeric enzyme was less thermostable than either the P. cinnabarinus laccase or the recombinant laccase produced in the same strain. Laccase-CBM was able to bind to a cellulosic substrate and, to a greater extent, to softwood kraft pulp. Binding to the pulp was shown to be mainly time and temperature-dependent. Laccase-CBM was further investigated for its softwood kraft pulp biobleaching potential and compared with the P. cinnabarinus laccase. Addition of a CBM was shown to greatly improve the delignification capabilities of the laccase in the presence of 1-hydroxybenzotriazole (HBT). In addition, ClO2 reduction using 5 U of chimeric enzyme per gram of pulp was almost double than that observed using 20 U of P. cinnabarinus laccase per gram of pulp. We demonstrated that conferring a carbohydrate binding capability to the laccase could significantly enhance its biobleaching properties
- Published
- 2009
4. Secretome analysis of Phanerochaete chrysosporium strains CIRM-BRFM41 grown on softwood
- Author
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Sacha Grisel, Catherine Lapierre, Brigitte Pollet, Holy Ravalason, Michel Petit-Conil, Frédérique Bertaud, Gwénaël Jan, Maryvonne Pasco, Marcel Asther, Daniel Mollé, Isabelle Herpoël-Gimbert, Jean-Claude Sigoillot, Pedro M. Coutinho, Biodiversité et Biotechnologie Fongiques (BBF), École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Science et Technologie du Lait et de l'Oeuf (STLO), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Architecture et fonction des Macromolécules Biologiques - UMR 6098 (AFMB), Université de Provence - Aix-Marseille 1-Centre National de la Recherche Scientifique (CNRS), Chimie Biologique (UCB), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Domaine Universitaire, Centre Technique du Papier (CTP), Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA)-École Centrale de Marseille (ECM), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and Centre National de la Recherche Scientifique (CNRS)-Université de Provence - Aix-Marseille 1
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Proteomics ,Softwood ,SECRETOME ,Molecular Sequence Data ,Phanerochaete ,Tandem mass spectrometry ,Lignin ,Applied Microbiology and Biotechnology ,CHEMICAL PULPING ,Fungal Proteins ,Industrial Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,Electrophoresis, Gel, Two-Dimensional ,Amino Acid Sequence ,SOFTWOOD ,protéome ,électrophorèse ,030304 developmental biology ,Chrysosporium ,Gel electrophoresis ,0303 health sciences ,Chlorine dioxide ,Phanerochaete chrysosporium ,Chromatography ,biology ,030306 microbiology ,General Medicine ,biology.organism_classification ,Wood ,champignon filamenteux ,Protein Transport ,filamentous fungus ,[SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology ,chemistry ,electrophoresis ,biology.protein ,Extracellular Space ,Kraft paper ,Biotechnology ,Peroxidase - Abstract
Abstract Proteomic analysis was performed to determine and differentiate the composition of the secretomes of Phanerochaete chrysosporium CIRM-BRFM41, a peroxidase hypersecretory strain grown under ligninolytic conditions and on softwood chips under biopulping conditions. Extracellular proteins from both cultures were analyzed by bidimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry. A total of 37 spots were identified. The secretome in liquid synthetic medium comprised mainly peroxidases, while several wood-degrading enzymes and enzymes involved in fungal metabolism were detected in biopulping cultures on softwood. This prompted an analysis of the impact of secretome modulation in the presence of softwood chips. Biotreated wood was submitted to kraft cooking and chemical bleaching using chlorine dioxide. The fungal pre-treatment led to a significant increase in pulp yield and a better bleachability of the pulp. This bleachability improvement could be explained by the production of specific lignocellulose-degrading enzymes.
- Published
- 2008
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