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Registros recuperados: 37 | |
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Abreu,Heber S.; Latorraca,João V.F.; Pereira,Regina P.W.; Monteiro,Maria Beatriz O.; Abreu,Fábio A.; Amparado,Kelysson F.. |
In spite of the great importance of cellulose the lignin is considered the second most abundant substance of the wood. However, little attention has been given it, mainly to wood properties. The lignin as well as other structural compounds (cellulose and hemicelluloses), has obviously an important role on the wood properties, probably due its composition and existent bonds. In general lignins have β-O-4 (Alkyl Aril Ether) as majoritary bond. This bond in a continued structure form big molecules with spiral conformation as virtual model. Based on this idea, lignins that have high/low β-O-4 content may have differentiated spiraled structures,suggesting different behaviors on the wood properties,which shows that the lignins (Guaicyl:Syringyl (GS)) of... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lignin; Molecular conformation; Wood properties; Structure. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652009000100014 |
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Soto Sánchez, Alfonso. |
El objetivo del presente trabajo fue conocer la acción enzimática del hongo basidiomiceto Pleurotus sapidus al actuar sobre los subproductos agroindustriales: Paja de cebada (PC), Raicilla (RC) y la Mezcla PC y RC 75:25 (M), además los cambios en su composición química que permitieran mejorar la digestibilidad de los subproductos usados en la alimentación de rumiantes. Se realizaron dos experimentos, el primero fue evaluar la actividad enzimática de lacasas, celulasas y xilanasas, a los 0, 8, 16 y 24 días de cultivo; las muestras obtenidas para cada tiempo se prensaron para obtener un extracto líquido (complejo enzimático) y posteriormente en el prensado residual se determinó la composición bromatológica de PC, RC y M en relación al valor inicial. Los... |
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Palavras-chave: Fermentación en sustrato sólido; Digestibilidad; AGV; FDN; FDA; Lignina; Fermentation in solid substrate; Digestibility; VFA; NDF; ADF; Lignin; Ganadería; Doctorado. |
Ano: 2009 |
URL: http://hdl.handle.net/10521/2396 |
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França, Andrezza Araújo; UFPB; Guim, Adriana; UFRPE; Batista, Ângela Maria Vieira; UFRPE; Pimentel, Rejane Magalhães de Mendonça; UFRPE; Ferreira, Geane Dias Gonçalves; UFRPE; Martins, Isis Darlene Sabóia Leal; UFRPE. |
Avaliaram-se a composição química, o teor de compostos secundários, a degradabilidade in situ, a anatomia e a degradabilidade dos tecidos do feno de maniçoba, a partir de plantas em início de frutificação, oriundas de uma vegetação de caatinga em Ibimirim, Estado do Pernambuco. O caule apresentou células com variados graus de lignificação, destacando-se a presença de fibras gelatinosas, parênquima medular lignificado e espessas paredes celulares no xilema. As folhas se destacam pela presença da estrutura girder, caracterizam-se pela grande quantidade de mesofilo, constituído por células com paredes delgadas, contribuindo para a degradabilidade de matéria seca. Idioblastos contendo drusas de oxalato foram encontrados nos tecidos vasculares, na nervura... |
Tipo: Análise laboratorial; discrição de caracteres |
Palavras-chave: Ciências Agrárias; Zootecnia; Pastagem e Forragicultura parede celular; Lignina; Microscopia vegetal; Digestibilidade; Forrageira nativa Pastagem e Forragicultura cell wall; Lignin; Plant microscopy; Digestibility; Native forage. |
Ano: 2010 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/8800 |
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Radomski, Maria Izabel; Bull, Leonardo Theodoro. |
A espécie medicinal Maytenus ilicifolia (Mart. ex Reiss.) localiza-se naturalmente sob diferentes condições edafoclimáticas. Isto implica em prováveis mecanismos de adaptação das populações naturais, cujas características químicas podem estar fixadas geneticamente. Este estudo foi desenvolvido para determinar a influência do ambiente sobre a composição fitoquímica de M. ilicifolia. Amostras de plantas foram coletadas em quatro populações naturais localizadas sobre diferentes superfícies geológicas no Estado do Paraná e sob distintas condições de luminosidade (pleno sol, meia sombra e sombra). Os solos foram classificados segundo o Sistema Brasileiro de Classificação. Foram avaliados os teores foliares de N, P, K, Ca, Mg, Fe, Mn, Cu, Zn, Si, Al, lignina,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Espinheira-santa lignina tanino silício. Espinheira-santa; Lignin; Tannin; Silicon.. |
Ano: 2010 |
URL: http://pfb.cnpf.embrapa.br/pfb/index.php/pfb/article/view/93 |
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Goes, Rafael Henrique de Tonissi e Buschinelli de; Universidade Federal da Grande Dourados; Miyagi, Eliane Sayuri; Universidade Federal da Grande Dourados; Oliveira, Euclides Reuter de; Universidade Federal da Grande Dourados; Brabes, Kelly Cristina da Silva; Universidade Federal da Grande Dourados; Patussi, Rosielen Augusto; Universidade Federal da Grande Dourados; Dambrós, Carlos Eduardo; Universidade Federal da Grande Dourados. |
Thirty-six experimental silos arranged in a completely randomized 4 x 3 factorial design were provided to evaluate the chemical changes of sunflower silage treated with soybean hulls, sunflower crushed and urea at 14, 21 and 28 days of ensilage. The additives were based on 5% natural matter, whereas control consisted of silage with 100% sunflower plant. OM, NDIP, and MM had average rates 911.2; 86.6 and 92.9 g kg-1 of dry matter respectively. The addition of soybean hulls and sunflower crushed increased DM rates after 28 and 21 days. Urea increased nitrogen fractions and the addition of soybean hulls increased total carbohydrate content of silage by 5.1%, whereas the addition of sunflower crushed decreased the same by 2.18%. NDF, ADF and hemicellulose... |
Tipo: Pesquisa |
Palavras-chave: 5.04.03.03-6 sunflower crushed; Lignin; NDF; PH; Soybean hulls; Urea. |
Ano: 2013 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/14049 |
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Gréggio,Thiago Claudino; Assis,Luiz Carlos; Nahas,Ely. |
The decomposition of soil litter contributes to maintaining agricultural sustainability, since the nutrients released by microbial activity are determinants of the net productivity of the agroecosystem. The decomposition of rubber tree (Hevea brasiliensis [Willd. ex A. Juss.] Müll. Arg.) leaves located on the surface and buried in at 10 cm depth in Forest and Savannah (Cerradão) soils (Oxisols) was studied, with emphasis on the production of CO2 and the monthly variation of the remaining amounts of litter mass, soluble substances, cellulose and lignin. To evaluate CO2 production, H. brasiliensis leaves were incubated for 30 days in soils from the 0-2 cm and 10-12 cm layers. CO2 production increased in the 0-2 cm layer in comparison to the 10-12 cm layer.... |
Tipo: Journal article |
Palavras-chave: Litter mass; Cellulose; Lignin; Soluble substances; Litter-bags. |
Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392008000200002 |
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Orrico,Ana Carolina Amorim; Centurion,Stanley Ribeiro; Farias,Romildo Marques de; Orrico Junior,Marco Antonio Previdelli; Garcia,Rodrigo Garófallo. |
The objective was to evaluate the differences between distinct types of litter material and their combinations in the dynamics of degradation on the organic matter fractions and the quality of the final compound. The treatments were established according to material used as substrate for broiler litter: treatment 1 - rice husks; 2 - sugar cane bagasse; 3 - wood shavings; 4 - wood shavings + sugar cane bagasse; 5 - rice husks + sugar cane bagasse; and 6 - Napier grass. The following variables were monitored: temperature, levels of total solids (TS), volatile solids (VS), mass and volume of the pile, fibrous fraction, and levels and reductions of N, P and K during the process. Piles formed with Napier grass and sugar cane bagasse presented the highest... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Broiler production; Cellulose; Lignin; Temperature; Total solids. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982012000700028 |
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Morais,Rafael Fiusa de; Souza,Bruno Juscelino de; Leite,José Marcos; Soares,Luis Henrique de Barros; Alves,Bruno José Rodrigues; Boddey,Robert Michael; Urquiaga,Segundo. |
The objective of this work was to evaluate elephant grass (Pennisetum purpureum Schum.) genotypes for bioenergy production by direct biomass combustion. Five elephant grass genotypes grown in two different soil types, both of low fertility, were evaluated. The experiment was carried out at Embrapa Agrobiologia field station in Seropédica, RJ, Brazil. The design was in randomized complete blocks, with split plots and four replicates. The genotypes studied were Cameroon, Bag 02, Gramafante, Roxo and CNPGL F06-3. Evaluations were made for biomass production, total biomass nitrogen, biomass nitrogen from biological fixation, carbon/nitrogen and stem/leaf ratios, and contents of fiber, lignin, cellulose and ash. The dry matter yields ranged from 45 to 67 Mg... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pennisetum purpureum; Ash; Agroenergy; Biological nitrogen fixation; Genotype; Lignin. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2009000200004 |
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Mauri,Janaína; Pereira,Daniele Laís; Silva,Gabrielle Avelar; Davide,Lisete Chamma; Techio,Vânia Helena; Souza Sobrinho,Fausto; Pereira,Fabricio José. |
ABSTRACT: The digestibility potential of leaves from forages depends on the amount of nutrition in their tissues, with low lignin deposition in the cell wall, mainly parenchyma and phloem. This research evaluated the leaf structure of different Urochloa genotypes and discussed its potential for evaluating digestibility. The cultivars U. brizantha, U. decumbens, U. ruziziensis and three clones of U. ruziziensis (1, 95 and 97), which are under development in breeding programs, were evaluated. Plants were grown under the recommended culture conditions for the Urochloa species. Plants were cut 60 days after sowing, and leaves were collected at 15 days of regrowth. Leaves were fixed in FAA 70 and further stored in 70% ethanol until being submitted to the usual... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Digestibility; Forage production; Leaf anatomy; Sclerenchyma; Lignin. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782019000400401 |
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Rasmussen-Poblete,Susana; Valdes,Jorge; Gamboa,Maria Cecilia; Valenzuela,Pablo D.T; Krauskopf,Erwin. |
Eucalyptus globulus is the most important commercial temperate hardwood in the world because of its wood properties and due to its characteristics for biofuel production. However, only a very low number of expressed sequence tags (ESTs) are publicly available for this tree species. We constructed a cDNA from E. globulus seedlings subjected to low temperature and sequenced 9,913 randomly selected clones, generating 8,737 curated ESTs. The assembly produced 1,062 contigs and 3,879 singletons forming a Eucalyptus unigene set. Based on BLASTX analysis, 89.3% of the contigs and 88.5% of the singletons had significant similarity to known genes in the non-redundant database of GenBank. The Eucalyptus unigene set generated is a valuable public resource that... |
Tipo: Journal article |
Palavras-chave: Cellulose; Cold-temperature; EST database; Forest biotechnology; Lignin. |
Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582008000200008 |
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Harakava,Ricardo. |
Eucalyptus ESTs libraries were screened for genes involved in lignin biosynthesis. This search was performed under the perspective of recent revisions on the monolignols biosynthetic pathway. Eucalyptus orthologues of all genes of the phenylpropanoid pathway leading to lignin biosynthesis reported in other plant species were identified. A library made with mRNAs extracted from wood was enriched for genes involved in lignin biosynthesis and allowed to infer the isoforms of each gene family that play a major role in wood lignin formation. Analysis of the wood library suggests that, besides the enzymes of the phenylpropanoids pathway, chitinases, laccases, and dirigent proteins are also important for lignification. Colocalization of several enzymes on the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Eucalyptus; Lignin; Expressed sequenced tag; Phenylpropanoids pathway; Monolignols. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000400015 |
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Lidija,Begović; Lepeduš,Hrvoje; Lalić,Alojzije; Štolfa,Ivna; Jurković,Zorica; Kovačević,Josip; Cesar,Vera. |
ABSTRACT The aim of this study was to investigate anatomical characteristics of barley (Hordeum vulgare L.) internodes and to reveal the connection with activity of guaiacol-peroxidases, their isoenzyme profiles, lignin, and cellulose content. Three lower internodes were sampled at elongation stage and differed in their anatomical features by showing that lignin deposition follows developmental pattern. Epidermis and hypodermis in the first internode were characterized by continuous layer of the lignified cells while in the second and third internode thin walled parenchyma cells could be observed in the hypodermis. These observations were in accordance with increment of peroxidase activity from the first to the third internode. Two acidic and 2 basic... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lignin; Cell wall; Internode; Hordeum vulgare L.. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052017000300352 |
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Registros recuperados: 37 | |
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