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Kokki Sakai - One of the best experts on this subject based on the ideXlab platform.
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Bleaching of Hardwood Kraft Pulp with Manganese Peroxidase Secreted from Phanerochaete sordida YK-624.
Applied and environmental microbiology, 1994Co-Authors: Ryuichiro Kondo, Koichi Harazono, Kokki SakaiAbstract:In vitro bleaching of an unbleached hardwood Kraft Pulp was performed with manganese peroxidase (MnP) from the fungus Phanerochaete sordida YK-624. When the Kraft Pulp was treated with partially purified MnP in the presence of MnSO(4), Tween 80, and sodium malonate with continuous addition of H(2)O(2) at 37 degrees C for 24 h, the Pulp brightness increased by about 10 points and the kappa number decreased by about 6 points compared with untreated Pulp. The Pulp brightness was also increased by 43 points to 75.5% by multiple (six) treatments with MnP combined with alkaline extraction. Our results indicate that in vitro degradation of residual lignin in hardwood Kraft Pulp with MnP is possible.
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In vitro bleaching of hardwood Kraft Pulp by extracellular enzymes excreted from white rot fungi in a cultivation system using a membrane filter.
Applied and environmental microbiology, 1994Co-Authors: Ryuichiro Kondo, Kenji Kurashiki, Kokki SakaiAbstract:To clarify the role of excreted extracellular enzymes during long-term incubation in a Pulp biobleaching system with white rot fungi, we developed a cultivation system in which a membrane filter is used; this membrane filter can prevent direct contact between hyphae and Kraft Pulp, but allows extracellular enzymes to attack the Kraft Pulp. Phanerochaete sordida YK-624 brightened the Pulp 21.4 points to 54.0% brightness after a 5-day in vitro treatment; this value was significantly higher than the values obtained with Phanerochaete chrysosporium and Coriolus versicolor after a 7-day treatment. Our results indicate that cell-free, membrane-filtered components from the in vitro bleaching system are capable of delignifying unbleached Kraft Pulp. Obvious candidates for filterable reagents capable of delignifying and bleaching Kraft Pulp are peroxidase and phenoloxidase proteins. The level of secreted manganese peroxidase activity in the filterable components was substantial during strain YK-624 in vitro bleaching. A positive correlation between the level of manganese peroxidase and brightening of the Pulp was observed.
Ryuichiro Kondo - One of the best experts on this subject based on the ideXlab platform.
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Bleaching of Hardwood Kraft Pulp with Manganese Peroxidase Secreted from Phanerochaete sordida YK-624.
Applied and environmental microbiology, 1994Co-Authors: Ryuichiro Kondo, Koichi Harazono, Kokki SakaiAbstract:In vitro bleaching of an unbleached hardwood Kraft Pulp was performed with manganese peroxidase (MnP) from the fungus Phanerochaete sordida YK-624. When the Kraft Pulp was treated with partially purified MnP in the presence of MnSO(4), Tween 80, and sodium malonate with continuous addition of H(2)O(2) at 37 degrees C for 24 h, the Pulp brightness increased by about 10 points and the kappa number decreased by about 6 points compared with untreated Pulp. The Pulp brightness was also increased by 43 points to 75.5% by multiple (six) treatments with MnP combined with alkaline extraction. Our results indicate that in vitro degradation of residual lignin in hardwood Kraft Pulp with MnP is possible.
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In vitro bleaching of hardwood Kraft Pulp by extracellular enzymes excreted from white rot fungi in a cultivation system using a membrane filter.
Applied and environmental microbiology, 1994Co-Authors: Ryuichiro Kondo, Kenji Kurashiki, Kokki SakaiAbstract:To clarify the role of excreted extracellular enzymes during long-term incubation in a Pulp biobleaching system with white rot fungi, we developed a cultivation system in which a membrane filter is used; this membrane filter can prevent direct contact between hyphae and Kraft Pulp, but allows extracellular enzymes to attack the Kraft Pulp. Phanerochaete sordida YK-624 brightened the Pulp 21.4 points to 54.0% brightness after a 5-day in vitro treatment; this value was significantly higher than the values obtained with Phanerochaete chrysosporium and Coriolus versicolor after a 7-day treatment. Our results indicate that cell-free, membrane-filtered components from the in vitro bleaching system are capable of delignifying unbleached Kraft Pulp. Obvious candidates for filterable reagents capable of delignifying and bleaching Kraft Pulp are peroxidase and phenoloxidase proteins. The level of secreted manganese peroxidase activity in the filterable components was substantial during strain YK-624 in vitro bleaching. A positive correlation between the level of manganese peroxidase and brightening of the Pulp was observed.
Tero Tynjala - One of the best experts on this subject based on the ideXlab platform.
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Biomass-based carbon capture and utilization in Kraft Pulp mills
Mitigation and Adaptation Strategies for Global Change, 2019Co-Authors: Katja Kuparinen, Esa Vakkilainen, Tero TynjalaAbstract:Corporate image, European Emission Trading System and Environmental Regulations, encourage Pulp industry to reduce carbon dioxide (CO_2) emissions. Kraft Pulp mills produce CO_2 mainly in combustion processes. The largest sources are the recovery boiler, the biomass boiler, and the lime kiln. Due to utilizing mostly biomass-based fuels, the CO_2 is largely biogenic. Capture and storage of CO_2 (CCS) could offer Pulp and paper industry the possibility to act as site for negative CO_2 emissions. In addition, captured biogenic CO_2 can be used as a raw material for bioproducts. Possibilities for CO_2 utilization include tall oil manufacturing, lignin extraction, and production of precipitated calcium carbonate (PCC), depending on local conditions and mill-specific details. In this study, total biomass-based CO_2 capture and storage potential (BECCS) and potential to implement capture and utilization of biomass-based CO_2 (BECCU) in Kraft Pulp mills were estimated by analyzing the impacts of the processes on the operation of two modern reference mills, a Nordic softwood Kraft Pulp mill with integrated paper production and a Southern eucalyptus Kraft Pulp mill. CO_2 capture is energy-intensive, and thus the effects on the energy balances of the mills were estimated. When papermaking is integrated in the mill operations, energy adequacy can be a limiting factor for carbon capture implementation. Global carbon capture potential was estimated based on Pulp production data. Kraft Pulp mills have notable CO_2 capture potential, while the on-site utilization potential using currently available technologies is lower. The future of these processes depends on technology development, desire to reuse CO_2, and prospective changes in legislation.
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Biomass-based carbon capture and utilization in Kraft Pulp mills
Mitigation and Adaptation Strategies for Global Change, 2019Co-Authors: Katja Kuparinen, Esa Vakkilainen, Tero TynjalaAbstract:Corporate image, European Emission Trading System and Environmental Regulations, encourage Pulp industry to reduce carbon dioxide (CO_2) emissions. Kraft Pulp mills produce CO_2 mainly in combustion processes. The largest sources are the recovery boiler, the biomass boiler, and the lime kiln. Due to utilizing mostly biomass-based fuels, the CO_2 is largely biogenic. Capture and storage of CO_2 (CCS) could offer Pulp and paper industry the possibility to act as site for negative CO_2 emissions. In addition, captured biogenic CO_2 can be used as a raw material for bioproducts. Possibilities for CO_2 utilization include tall oil manufacturing, lignin extraction, and production of precipitated calcium carbonate (PCC), depending on local conditions and mill-specific details. In this study, total biomass-based CO_2 capture and storage potential (BECCS) and potential to implement capture and utilization of biomass-based CO_2 (BECCU) in Kraft Pulp mills were estimated by analyzing the impacts of the processes on the operation of two modern reference mills, a Nordic softwood Kraft Pulp mill with integrated paper production and a Southern eucalyptus Kraft Pulp mill. CO_2 capture is energy-intensive, and thus the effects on the energy balances of the mills were estimated. When papermaking is integrated in the mill operations, energy adequacy can be a limiting factor for carbon capture implementation. Global carbon capture potential was estimated based on Pulp production data. Kraft Pulp mills have notable CO_2 capture potential, while the on-site utilization potential using currently available technologies is lower. The future of these processes depends on technology development, desire to reuse CO_2, and prospective changes in legislation.
Fred S Archibald - One of the best experts on this subject based on the ideXlab platform.
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Kraft Pulp bleaching and delignification by trametes versicolor
Journal of Biotechnology, 1997Co-Authors: Fred S Archibald, Regis Bourbonnais, Laura Jurasek, M.g. Paice, I D ReidAbstract:In 1989 we reported that the white-rot basidiomycete fungus Trametes versicolor could delignify and substantially brighten unbleached Kraft Pulps. Since that time, considerable effort has been dedicated to understanding the biological mechanisms of this efficient delignification system in the hope that part or all of the system can be applied industrially. Early work indicated that all components necessary for extensive Kraft Pulp bleaching and delignification are secreted by the fungus, but that one or more of these components must be constantly replaced or renewed. T. versicolor can bleach O2-delignified and extended-cooking Pulps as well as conventional hardwood and softwood Kraft Pulps. The fungus demethylates and solubilizes the residual lignin in the Pulps, seemingly without depolymerization. Enzyme families secreted by T. versicolor which may be involved in delignification include lignin peroxidases (LiP), manganese peroxidases (MnP), laccases, and cellobiose dehydrogenases (CDH). Each of these families has been investigated for its interactions with Kraft Pulp lignin. Two laccase isozymes (laccase I and II) have been purified. The reactivities of the two isozymes on all substrates tested, including Kraft lignin, were similar, with no evidence of lignin depolymerization by either enzyme. However the presence of the mediator 2,2′-azinobis (3-ethylbenzthiazoline-6-sulphonate) (ABTS) prevented and reversed the polymerization of Kraft lignin by either laccase. Both laccases were able to delignify Kraft Pulp, but only in the presence of the mediator. Secreted MnP activity and the presence of substantial available Mn(II) ions appear necessary for delignification and Pulp brightening by T. versicolor. Mutants unable to secrete MnP cannot delignify. Purified MnP substantially delignifies Pulp when supplied with Mn (II), H2O2 and Mn (II)-complexing agents. Furthermore, the resulting Pulp is made easier to bleach to high brightness with alkaline hydrogen peroxide. LiP, while produced under secondary metabolic conditions, appears to play no role in the delignification of Kraft Pulp by T. versicolor. White-rot fungi typically carry out net oxidation of the lignin and hydrolytic depolymerization of the carbohydrate in wood. Is there likely to be a significant role in delignification for enzymes which oxidize wood carbohydrates and reduce lignin? The family of carbohydrate-oxidizing, quinone-, metal ion- and organic free radical-reducing enzymes known as the cellobiose oxidases and cellobiose dehydrogenases (CBO, CDH, formerly CBQase) are reported to occur in a number of wood-degrading fungi. A CDH from T. versicolor has been purified, characterized and shown to decolorize and prevent laccase-mediated lignin polymerization. It can help supply MnP with chelator, hydrogen peroxide, and manganese. The rate of diffusion of enzymes or mediators in the Kraft fiber wall may be a limiting factor for delignification. In order to visualize these diffusion bottlenecks we have built a model of the secondary wall and compared the pore sizes in the wall with the sizes of potential diffusible delignification agents.
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Kraft Pulp bleaching and delignification by dikaryons and monokaryons of trametes versicolor
Applied and Environmental Microbiology, 1993Co-Authors: Katherine Addleman, Fred S ArchibaldAbstract:The ability of 10 dikaryotic and 20 monokaryotic strains of Trametes (Coriolus) versicolor to bleach and delignify hardwood and softwood Kraft Pulps was assessed. A dikaryon (52P) and two of its mating-compatible monokaryons (52J and 52D) derived via protoplasting were compared. All three regularly bleached hardwood Kraft Pulp more than 20 brightness points (International Standards Organization) in 5 days and softwood Kraft Pulp the same amount in 12 days. Delignification (kappa number reduction) by the dikaryon and the monokaryons was similar, but the growth of the monokaryons was slower. Insoluble dark pigments were commonly found in the mycelium, medium, and Pulp of the dikaryon only. Laccase and manganese peroxidase (MnP) but not lignin peroxidase activities were secreted during bleaching by all three strains. Their laccase and MnP isozyme patterns were compared on native gels. No segregation of isozyme bands between the monokaryons was found. Hardwood Kraft Pulp appeared to adsorb several laccase isozyme bands. One MnP isozyme (pI, 3.2) was secreted in the presence of Pulp by all three strains, but a second (pI, 4.9) was produced only by 52P. A lower level of soluble MnP activity in one monokaryon (52D) was associated with reduced bleaching ability and a lower level of methanol production. Since monokaryon 52J bleached Pulp better than its parent dikaryon 52P, especially per unit of biomass, this genetically simpler monokaryon will be the preferred subject for further genetic manipulation and improvement of fungal Pulp biological bleaching.
Herbert Sixta - One of the best experts on this subject based on the ideXlab platform.
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Ionic liquid extraction method for upgrading eucalyptus Kraft Pulp to high purity dissolving Pulp
Cellulose, 2014Co-Authors: Annariikka Roselli, Michael Hummel, Alireza Monshizadeh, Thaddeus Maloney, Herbert SixtaAbstract:High purity cellulose from wood is an important raw material for many applications such as cellulosic fibers, films or the manufacture of various cellulose acetate products. Hitherto, multi-step refining processes are needed for an efficient hemicellulose removal, most of them suffering from severe cellulose losses. Recently, a novel method for producing high purity cellulose from bleached paper grade birch Kraft Pulp was presented. In this so called IONCELL process, hemicelluloses are extracted by an ionic liquid–water mixture and both fractions can be recovered without yield losses or polymer degradation. Herein, it is demonstrated that bleached Eucalyptus urograndis Kraft Pulp can be refined to high purity acetate grade Pulp via the IONCELL process. The hemicellulose content could be reduced from initial 16.6 to 2.4 wt% while persevering the cellulose I crystal form by using an optimized 1-ethyl-3-methylimidazolium dimethylphosphate-water mixture as the extraction medium. The degree of polymerization was then reduced by a sulfuric acid treatment for subsequent acetylation of the Pulp, resulting in a final hemicellulose content of 2.2 wt%. When pre-treating the Pulp enzymatically with endoxylanase, the final hemicellulose content could be reduced even to 1.7 wt%. For comparison, the eucalyptus Kraft Pulp was also subjected to cold caustic extraction and the same subsequent acid treatment which led to 3.9 wt% of residual hemicelluloses. The performance in acetylation of all produced Pulps was tested and compared to commercial acetate grade Pulp. The endoxylanase-IONCELL-treated Pulp showed superior properties. Thus, an ecologically and economically efficient alternative for the production of highest value cellulose Pulp is presented.
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ionic liquid extraction method for upgrading eucalyptus Kraft Pulp to high purity dissolving Pulp
Cellulose, 2014Co-Authors: Annariikka Roselli, Michael Hummel, Alireza Monshizadeh, Thaddeus Maloney, Herbert SixtaAbstract:High purity cellulose from wood is an important raw material for many applications such as cellulosic fibers, films or the manufacture of various cellulose acetate products. Hitherto, multi-step refining processes are needed for an efficient hemicellulose removal, most of them suffering from severe cellulose losses. Recently, a novel method for producing high purity cellulose from bleached paper grade birch Kraft Pulp was presented. In this so called IONCELL process, hemicelluloses are extracted by an ionic liquid–water mixture and both fractions can be recovered without yield losses or polymer degradation. Herein, it is demonstrated that bleached Eucalyptus urograndis Kraft Pulp can be refined to high purity acetate grade Pulp via the IONCELL process. The hemicellulose content could be reduced from initial 16.6 to 2.4 wt% while persevering the cellulose I crystal form by using an optimized 1-ethyl-3-methylimidazolium dimethylphosphate-water mixture as the extraction medium. The degree of polymerization was then reduced by a sulfuric acid treatment for subsequent acetylation of the Pulp, resulting in a final hemicellulose content of 2.2 wt%. When pre-treating the Pulp enzymatically with endoxylanase, the final hemicellulose content could be reduced even to 1.7 wt%. For comparison, the eucalyptus Kraft Pulp was also subjected to cold caustic extraction and the same subsequent acid treatment which led to 3.9 wt% of residual hemicelluloses. The performance in acetylation of all produced Pulps was tested and compared to commercial acetate grade Pulp. The endoxylanase-IONCELL-treated Pulp showed superior properties. Thus, an ecologically and economically efficient alternative for the production of highest value cellulose Pulp is presented.
