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Pesquisa : D08.811.277.450.420.200 [Categoria DeCS]
Referências encontradas : 21 [refinar]
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  1 / 21 LILACS  
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Id: biblio-1087169
Autor: Rodríguez-Mendoza, Johan; Santiago-Hernández, Alejandro; Alvarez-Zúñiga, María Teresa; Gutiérrez-Antón, Marina; Aguilar-Osorio, Guillermo; Hidalgo-Lara, María Eugenia.
Título: Purification and biochemical characterization of a novel thermophilic exo-ß-1, 3-glucanase from the thermophile biomass-degrading fungus Thielavia terrestris Co3Bag1
Fonte: Electron. j. biotechnol;41:60-71, sept. 2019. graf, tab, ilus.
Idioma: en.
Projeto: Departamento de Biotecnología y Bioingeniería, CINVESTAV-IPN, México.
Resumo: Background: The aim of this work was to purify and characterize exo-ß-1,3-glucanase, namely, TtBgnA, from the thermophilic fungus Thielavia terrestris Co3Bag1 and to identify the purified enzyme. Results: The thermophilic biomass-degrading fungus T. terrestris Co3Bag1 displayed ß-1,3-glucanase activity when grown on 1% glucose. An exo-ß-1,3-glucanase, with an estimated molecular mass of 129 kDa, named TtBgnA, was purified from culture filtrates from T. terrestris Co3Bag1. The enzyme exhibited optimum activity at pH 6.0 and 70°C and half-lives (t1/2) of 54 and 37 min at 50 and 60°C, respectively. Substrate specificity analysis showed that laminarin was the best substrate studied for TtBgnA. When laminarin was used as the substrate, the apparent KM and Vmax values were determined to be 2.2 mg mL-1 and 10.8 U/mg, respectively. Analysis of hydrolysis products by thin-layer chromatography (TLC) revealed that TtBgnA displays an exo mode of action. Additionally, the enzyme was partially sequenced by tandem mass spectrometry (MS/MS), and the results suggested that TtBgnA from T. terrestris Co3Bag1 could be classified as a member of the GH-31 family. Conclusions: This report thus describes the purification and characterization of TtBgnA, a novel exo-ß-1,3-glucanase of the GH-31 family from the thermophilic fungus T. terrestris Co3Bag1. Based on the biochemical properties displayed by TtBgnA, the enzyme could be considered as a candidate for potential biotechnological applications.
Descritores: Sordariales/enzimologia
Glucana 1,3-beta-Glucosidase/química
-Temperatura
Estabilidade Enzimática
Celulases
Glucana 1,3-beta-Glucosidase/isolamento & purificação
Eletroforese em Gel de Poliacrilamida
Espectrometria de Massas em Tandem
Ensaios Enzimáticos
Concentração de Íons de Hidrogênio
Responsável: CL1.1 - Biblioteca Central


  2 / 21 LILACS  
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Id: biblio-1053552
Autor: Smuga-Kogut, Malgorzata; Piskier, Tomasz; Walendzik, Bartosz; Szymanowska-Powalowska, Daria.
Título: Assessment of wasteland derived biomass for bioethanol production
Fonte: Electron. j. biotechnol;41:1-8, sept. 2019. tab, ilus, graf.
Idioma: en.
Projeto: National Science Centre as part of MINIATURA 1.
Resumo: Background: The bioethanol produced from biomass is a promising alternative fuel. The lignocellulose from marginal areas or wasteland could be a promising raw material for bioethanol production because it is present in large quantities, is cheap, renewable and has favorable environmental properties. Despite these advantages, lignocellulosic biomass is much more difficult to process than cereal grains, due to the need for intensive pretreatment and relatively large amounts of cellulases for efficient hydrolysis. Therefore, there is a need to develop an efficient and cost-effective method for the degradation and fermentation of lignocellulosic biomass to ethanol. Results: The usefulness of lignocellulosic biomass from wasteland for the production of bioethanol using pretreatment with the aid of ionic liquids of 1-ethyl-3-methylimidazolium acetate and 1-ethyl-3-methylimidazolium chloride was evaluated in this study. The pretreatment process, enzymatic hydrolysis and alcoholic fermentation lasted a total of 10 d. The largest amounts of bioethanol were obtained from biomass originating from agricultural wasteland, in which the dominant plant was fireweed (Chamaenerion angustifolium) and from the field where the common broom (Cytisus scoparius) was the dominant. Conclusions: The plants such as fireweed, common broom, hay and goldenrod may be useful for the production of liquid biofuels and it would be necessary in the further stage of research to establish and optimize the conditions for the technology of ethyl alcohol producing from these plant species. Enzymatic hydrolysis of biomass from agricultural wastelands results in a large increase in fermentable sugars, comparable to the enzymatic hydrolysis of rye, wheat, rice or maize straw.
Descritores: Solo/química
Biomassa
Etanol/metabolismo
-Biodegradação Ambiental
Celulases/análise
Enzimas/metabolismo
Líquidos Iônicos
Biocombustíveis
Hidrólise
Lignina/análise
Responsável: CL1.1 - Biblioteca Central


  3 / 21 LILACS  
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Id: biblio-1049943
Autor: Pena Júnior, Carlos Eduardo.
Título: Efeito das glicosilações sobre a estrutura e dinâmica da celulase Cel7A de Trichoderma reesei / Effect of glycosylations on the structure and dynamics of Cel7A cellulase from Trichoderma reesei.
Fonte: Rio de Janeiro; s.n; 2019. xiv, 152 p. ilus.
Idioma: pt.
Tese: Apresentada a Instituto Oswaldo Cruz para obtenção do grau de Doutor.
Resumo: Celulases fúngicas têm sido usadas para degradar a biomassa lignocelulósica para a produção de bioetanol. Celulases industriais como Cel7A de Trichoderma reesei (TrCel7A) são críticas neste processo. A compreensão da estrutura e dinâmica é crucial para a reengenharia da atividade celulolítica. Esta enzima é formada por dois domínios ligados por um linker flexível e altamente glicosilado. No entanto, a flexibilidade do linker tem dificultado a determinação da estrutura completa da Cel7A. Assim, na ausência de dados experimentais de alta resolução, aplicamos a modelagem integrativa para construir um modelo da enzima completa. Em seguida, estudamos os efeitos da glicosilação na estrutura e dinâmica da apo TrCel7A por meio de simulações. A análise da dinâmica essencial mostrou que a O-glicosilação no linker levou à estabilização da dinâmica global da proteína. Os glicanos O-ligados parecem restringir a distribuição dos ângulos diedros desta região, selecionando conformações mais alongadas. Além da flexibilidade reduzida, os movimentos interdomínios funcionais foram preservados no sistema glicosilado. Em contraste, observamos grande plasticidade conformacional na ausência de glicosilação, mas os domínios funcionais frequentemente colapsaram. Nós relatamos aqui evidências de que a flexibilidade dirigida no linker de Cel7A por mutações pontuais, incluindo modificações de sítios de glicosilação, poderia ser uma estratégia promissora para melhorar a atividade da celulase. (AU)
Descritores: Trichoderma
Glicosilação
Mutagênese Insercional
Celulases
Limites: Humanos
Responsável: BR15.1 - Biblioteca de Ciências Biomédicas


  4 / 21 LILACS  
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Texto completo SciELO Brasil
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Id: biblio-1039268
Autor: Cardoso, Wilton Soares; Queiroz, Paula Viana; Tavares, Gabriella Peterlini; Santos, Fernando Almeida; Soares, Filippe Elias de Freitas; Kasuya, Maria Catarina Megumi; Queiroz, José Humberto de.
Título: Multi-enzyme complex of white rot fungi in saccharification of lignocellulosic material
Fonte: Braz. j. microbiol;49(4):879-884, Oct.-Dec. 2018. tab, graf.
Idioma: en.
Resumo: ABSTRACT The multi-enzyme complex (crude extract) of white rot fungi Pleurotus ostreatus, Pleurotus eryngii, Trametes versicolor, Pycnosporus sanguineus and Phanerochaete chrysosporium were characterized, evaluated in the hydrolysis of pretreated pulps of sorghum straw and compared efficiency with commercial enzyme. Most fungi complexes had better hydrolysis rates compared with purified commercial enzyme.
Descritores: Proteínas Fúngicas/química
Sorghum/química
Celulases/química
Fungos/enzimologia
Lignina/química
-Proteínas Fúngicas/metabolismo
Caules de Planta/microbiologia
Caules de Planta/química
Sorghum/microbiologia
Celulases/metabolismo
Biocatálise
Fungos/química
Hidrólise
Lignina/metabolismo
Responsável: BR1.1 - BIREME


  5 / 21 LILACS  
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Martins, Meire Lelis Leal
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Id: biblio-849049
Autor: Oliveira, Luciana Ribeiro Coutinho; Barbosa, João Batista; Martins, Meire Lelis Leal; Martins, Marco Antônio.
Título: Extracellular production of avicelase by the thermophilic soil bacterium Bacillus sp SMIA-2 / Produção de avicelase extracelular pela bactéria termofílica Bacillus sp SMIA-2
Fonte: Acta sci., Biol. sci;36(2):215-222, abr.- jun. 2014. ilus, tab.
Idioma: en.
Resumo: Nowadays, the isolation of new bacterial strains that produce enzymes with novel properties is a subject of great relevance to the scientific community. This study, in order to search for producers of new cellulase strains, investigated the avicelase production by thermophilic Bacillus sp. strain SMIA-2. The best avicelase activity was observed in a culture medium containing 0.5% (w v-1) avicel and 0.5% (w v-1) corn steep liquor with initial pH 7.5- 8.0 incubated at 50 oC. When avicel was replaced in the medium by the treated sugarcane bagasse (0.5%, w v-1) the avicelase activity levels were not affected. Studies on the avicelase characterization revealed that the optimum pH of the enzyme was found to be 8.5 and the enzyme retained more than 80% of its activity after incubation at room temperature for 2h at pH 6.5-8.5. The optimum temperature of this enzyme was 70oC and the enzyme retained 67% of the original activity after 20 min. of heat treatment at 70oC. Avicelase was stimulated by Mn2+ and Co2+, whereas Hg2+ greatly inhibited the enzyme activity.

Atualmente, o isolamento de estirpes de bactérias que produzem enzimas com novas propriedades é um tema de grande relevância para a comunidade científica. Este trabalho, buscando por novas cepas produtoras de celulases, investigou a produção de avicelases pelo termofílico Bacillus sp. cepa SMIA-2. A melhor atividade da enzima foi obtida em uma cultura contendo 0,5% (p v-1) avicel e 0,5% (p v-1) água de maceração de milho com pH inicial de pH 7,5-8,0 e incubada a 50oC. A substituição da avicel no meio de cultura pelo bagaço de cana- de- açúcar tratado (0,5%, p v-1) não afetou os níveis de atividade da avicelase. Estudos sobre a caracterização da avicelase revelaram que o pH para atividade ótima da enzima foi 8,5 e que a mesma reteve mais de 80% de sua atividade após ser incubada à temperatura ambiente por 2 h a pH 6,5-8,5. A temperatura ótima da avicelase foi 70oC e a enzima reteve 67% da sua atividade original após 20 min. de incubação a 70oC. A avicelase foi estimulada pelos íons Mn2+ e Co2+, ao passo que Hg2+ inibiu a atividade da enzima.
Descritores: Bacillus
Celulases
Saccharum
Zea mays
Responsável: BR513.1 - Biblioteca Central


  6 / 21 LILACS  
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Id: biblio-847977
Autor: Faheina Junior, Genilton da Silva; Amorim, Mariza Vieira da Fonseca Sabóia; Souza, Caroline Gondim de; Sousa, Diego Menezes de; Sousa, Kally Alves de; Pinto, Gustavo Adolfo Saavedra.
Título: Strategies to increase cellulase production with submerged fermentation using fungi isolated from the Brazilian biome / Estratégias para produção de celulases através de fermentação submersa utilizando fungos isolados do bioma brasileiro
Fonte: Acta sci., Biol. sci;37(1):15-22, jan.- mar. 2015. ilus.
Idioma: en.
Resumo: Studies on new microbial sources of cellulase and accurate assessment of the steps that increase cellulase production are essential strategies to reduce costs of various processes using such enzymes. This study aimed at the selection of cellulase-producing filamentous fungi, and at the research of parameters involving cellulase production by submerged fermentation. The first test consisted of selecting the best cellulase-producing microorganisms (FPase) in Erlenmeyer flasks containing 200 mL of specific growth medium. The next test was designed to further investigate the enzyme production in fermentation with four types of soluble sugars: glucose, lactose, sucrose and xylose. In bioreactor tests, three different inoculation strategies were analyzed. The best FPase activity was presented by the strain Trichoderma sp. CMIAT 041 (49.9 FPU L-1) and CMCase by the fungus Lasiodiplodia theobromae CMIAT 096 (350.0 U L-1). Sucrose proved to be the best option among the soluble sugars tested, with higher rates of FPase activity (49.9 FPU L-1) and CMCase (119.7 U L-1). The best inoculation strategy for the bioreactor was a spore suspension obtained from a semi-solid state fermentation of wheat bran for 72h.

Estudos sobre novas fontes microbianas e análises mais acuradas das etapas que compõem a produção de celulases são essenciais como estratégias para diminuir os custos gerados pelo uso de celulases nos processos de obtenção de açúcares fermentescíveis. O trabalho teve como objetivo a seleção de fungos filamentosos produtores de celulases e a investigação de parâmetros que envolvem a produção enzimática em fermentação submersa. O primeiro teste consistiu em selecionar os melhores fungos produtores de celulases totais em frascos Erlenmeyer contendo 200 mL de meio de cultura específico. O teste subsequente teve o intuito de investigar a produção enzimática com quatro tipos de açúcares solúveis: glicose, lactose, sacarose e xilose. Nos testes em biorreator foram analisados três diferentes estratégias de inoculação. Na etapa de seleção a melhor atividade de FPase foi apresentada por Trichoderma sp. CMIAT 041 (49,9 FPU L-1) e CMCase pelo fungo Lasiodiplodia theobromae CMIAT 096 (350,0 U L-1). O uso de sacarose mostrou-se ser a melhor opção dentre os açúcares solúveis testados, apresentando os maiores valores de atividade de FPase (49,9 FPU L-1) e CMCase (119,7 U L-1). A melhor estratégia de inoculação foi a suspensão de esporos obtidos a partir de fermentação em farelo de trigo, no tempo 72h.
Descritores: Brasil
Celulases
Ecossistema
Fermentação
Fungos
Responsável: BR513.1 - Biblioteca Central


  7 / 21 LILACS  
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Texto completo SciELO Chile
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Id: biblio-840317
Autor: Bai, Xi; Yuan, Xianjun; Wen, Aiyou; Li, Junfeng; Bai, Yunfeng; Shao, Tao.
Título: Efficient expression and characterization of a cold-active endo-1, 4-β -glucanase from Citrobacter farmeri by co-expression of Myxococcus xanthus protein S
Fonte: Electron. j. biotechnol;19(6):79-83, Nov. 2016. ilus.
Idioma: en.
Projeto: Independent Innovation of Agricultural Sciences in Jiang Su Province; . National key Research and Development Program; . Network and Technology Served of Chinese Academy of Sciences Program (STS). Grassland agricultural system construction and industrialization demonstration of typical village (Jina village) in Tibet.
Resumo: Background: Cold-active endo-1, 4-β-glucanase (EglC) can decrease energy costs and prevent product denaturation in biotechnological processes. However, the nature EglC from C. farmeri A1 showed very low activity (800 U/L). In an attempt to increase its expression level, C. farmeri EglC was expressed in Escherichia coli as an N-terminal fusion to protein S (ProS) from Myxococcus xanthus. Results: A novel expression vector, pET(ProS-EglC), was successfully constructed for the expression of C. farmeri EglC in E. coli. SDS-PAGE showed that the recombinant protein (ProS-EglC) was approximately 60 kDa. The activity of ProS-EglC was 12,400 U/L, which was considerably higher than that of the nature EglC (800 U/L). ProS-EglC was active at pH 6.5-pH 8.0, with optimum activity at pH 7.0. The recombinant protein was stable at pH 3.5-pH 6.5 for 30 min. The optimal temperature for activity of ProS-EglC was 30°C-40°C. It showed greater than 50% of maximum activity even at 5°C, indicating that the ProS-EglC is a cold-active enzyme. Its activity was increased by Co2+ and Fe2+, but decreased by Cd2+, Zn2+, Li+, methanol, Triton-X-100, acetonitrile, Tween 80, and SDS. Conclusions: The ProS-EglC is promising in application of various biotechnological processes because of its cold-active characterizations. This study also suggests a useful strategy for the expression of foreign proteins in E. coli using a ProS tag.
Descritores: Celulases/metabolismo
Citrobacter/enzimologia
Escherichia coli/enzimologia
Myxococcus xanthus/enzimologia
-Temperatura Baixa
Vetores Genéticos
Proteínas Recombinantes
Responsável: CL1.1 - Biblioteca Central


  8 / 21 LILACS  
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Texto completo SciELO Chile
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Id: biblio-840314
Autor: Lin, Ling; Liu, Xiaozhou; Zhou, Yating; Guan, Linyan; Jiajia, He; Huang, Weiqian.
Título: A novel pH-stable, endoglucanase (JqCel5A) isolated from a salt-lake microorganism, Jonesia quinghaiensis
Fonte: Electron. j. biotechnol;19(6):56-62, Nov. 2016. ilus.
Idioma: en.
Projeto: Key Laboratory of Biotic Environment and Ecology Safety in Anhui Province. Anhui Provincial Natural Science Foundation.
Resumo: Background: Endoglucanase, one of three type cellulases, can randomly cleave internal p-1,4-linkages in cellulose polymers. Thus, it could be applied in agricultural and industrial processes. Results: A novel endoglucanase gene (JqCel5A) was cloned from Jonesia quinghaiensis and functionally expressed in Escherichia coli Rosetta (DE3). It contained 1722 bp and encoded a 573-residue polypeptide consisting of a catalytic domain of glycoside hydrolase family 5 (GH5) and a type 2 carbohydrate-binding module (CBM2), together with a predicted molecular mass of 61.79 kD. The purified JqCel5A displayed maximum activity at 55°C and pH 7.0, with 21.7 U/mg, 26.19 U/mg and 4.81 U/mg towards the substrate carboxymethyl cellulose, barley glucan and filter paper, respectively. Interestingly, JqCel5A exhibited high pH stability over a broad pH range of pH (3-11), and had good tolerance to a wide variety of deleterious chemicals including heavy metals and detergent. The catalytic mechanism of JqCel5A was also investigated by site mutagenesis and homology-modeling in this study. Conclusions: It was believed that these properties might make JqCel5A to be potentially used in the suitable industrial catalytic condition, which has a broad pH fluctuation and/or chemical disturbance.
Descritores: Actinomycetales/enzimologia
Celulases/química
Celulases/isolamento & purificação
-Celulases/genética
Concentração de Íons de Hidrogênio
Testes de Mutagenicidade
Temperatura
Responsável: CL1.1 - Biblioteca Central


  9 / 21 LILACS  
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Texto completo SciELO Brasil
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Id: lil-775128
Autor: Alrumman, Sulaiman A..
Título: Enzymatic saccharification and fermentation of cellulosic date palm wastes to glucose and lactic acid
Fonte: Braz. j. microbiol;47(1):110-119, Jan.-Mar. 2016. tab, graf.
Idioma: en.
Resumo: Abstract The bioconversion of cellulosic wastes into high-value bio-products by saccharification and fermentation processes is an important step that can reduce the environmental pollution caused by agricultural wastes. In this study, enzymatic saccharification of treated and untreated date palm cellulosic wastes by the cellulases from Geobacillus stearothermophilus was optimized. The alkaline pre-treatment of the date palm wastes was found to be effective in increasing the saccharification percentage. The maximum rate of saccharification was found at a substrate concentration of 4% and enzyme concentration of 30 FPU/g of substrate. The optimum pH and temperature for the bioconversions were 5.0 and 50 °C, respectively, after 24 h of incubation, with a yield of 31.56 mg/mL of glucose at a saccharification degree of 71.03%. The saccharification was increased to 94.88% by removal of the hydrolysate after 24 h by using a two-step hydrolysis. Significant lactic acid production (27.8 mg/mL) was obtained by separate saccharification and fermentation after 72 h of incubation. The results indicate that production of fermentable sugar and lactic acid is feasible and may reduce environmental pollution by using date palm wastes as a cheap substrate.
Descritores: Celulases/metabolismo
Celulose/metabolismo
Geobacillus stearothermophilus/enzimologia
Glucose/metabolismo
Resíduos Industriais
Ácido Láctico/metabolismo
Phoeniceae/metabolismo
-Álcalis
Biotransformação
Fermentação
Concentração de Íons de Hidrogênio
Phoeniceae/efeitos dos fármacos
Temperatura
Responsável: BR1.1 - BIREME


  10 / 21 LILACS  
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Id: lil-769645
Autor: Isaac, George Saad; Abu-Tahon, Medhat Ahmed.
Título: Enhanced alkaline cellulases production by the thermohalophilic Aspergillus terreus AUMC 10138 mutated by physical and chemical mutagens using corn stover as substrate
Fonte: Braz. j. microbiol;46(4):1269-1277, Oct.-Dec. 2015. tab, graf.
Idioma: en.
Resumo: Abstract A thermohalophilic fungus, Aspergillus terreus AUMC 10138, isolated from the Wadi El-Natrun soda lakes in northern Egypt was exposed successively to gamma and UV-radiation (physical mutagens) and ethyl methan-sulfonate (EMS; chemical mutagen) to enhance alkaline cellulase production under solid state fermentation (SSF) conditions. The effects of different carbon sources, initial moisture, incubation temperature, initial pH, incubation period, inoculum levels and different concentrations of NaCl on production of alkaline filter paper activity (FPase), carboxymethyl cellulase (CMCase) and β-glucosidase by the wild-type and mutant strains of A. terreus were evaluated under SSF. The optimum conditions for maximum production of FPase, CMCase and β-glucosidase were found to be the corn stover: moisture ratio of 1:3(w/v), temperature 45 °C, pH range, 9.0–11.0, and fermentation for 4, 4 and 7 day, respectively. Inoculum levels of 30% for β-glucosidase and 40% for FPase, CMCase gave the higher cellulase production by the wild-type and mutant strains, respectively. Higher production of all three enzymes was obtained at a 5% NaCl. Under the optimized conditions, the mutant strain A. terreus M-17 produced FPase (729 U/g), CMCase (1,783 U/g), and β-glucosidase (342 U/g), which is, 1.85, 1.97 and 2.31-fold higher than the wild-type strain. Our results confirmed that mutant strain M-17 could be a promising alkaline cellulase enzyme producer employing lignocellulosics especially corn stover.
Descritores: Aspergillus/enzimologia
Aspergillus/metabolismo
Celulases/metabolismo
Mutagênese
Zea mays/metabolismo
-Aspergillus/efeitos dos fármacos
Aspergillus/efeitos da radiação
Meios de Cultura/química
Egito
Metanossulfonato de Etila
Concentração de Íons de Hidrogênio
Lagos/microbiologia
Técnicas Microbiológicas
Cloreto de Sódio/metabolismo
Temperatura
Raios Ultravioleta
Responsável: BR1.1 - BIREME



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