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Search Results: 1 - 10 of 56246 matches for " Ursula Fabiola Rodríguez-Zú?iga "
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Produ??o de celulases por Aspergillus niger por fermenta??o em estado sólido
Rodríguez-Zú?iga, Ursula Fabiola;Farinas, Cristiane Sanchez;Bertucci Neto, Victor;Couri, Sonia;Crestana, Silvio;
Pesquisa Agropecuária Brasileira , 2011, DOI: 10.1590/S0100-204X2011000800018
Abstract: the objective of this work was to evaluate cellulase enzyme production by the filamentous fungus aspergillus niger by solid-state fermentation of different substrates. the solid substrates sugarcane bagasse, wheat bran, soybean meal, and their mixtures were evaluated. the effects of substrate moisture contents (60, 70, and 80% in humid basis) and of the supplementation with culture media: sucrose, basic mandels & weber, modified mandels & weber, with the addition of carboxymethyl cellulose, and czapeck dox, were evaluated in substrate with 90% bagasse and 10% soybean meal. the highest total cellulose and endoglucanase activities, in wheat bran, were obtained after 72 hours: 0.4 and 21.0 iu g-1, respectively. there was an expressive increase in enzymatic activities as the proportion of bran in the substrate increased, in comparison to fermentation with sugarcane bagasse only. the 50% moisture content was insufficient to fully hydrate sugarcane bagasse, and the ideal humidity varies according to the medium used for supplementation and is between 70 and 80%. the modified mandels &weber medium shows the best result as an inductor of enzymatic activity.
Production of Biomass-Degrading Multienzyme Complexes under Solid-State Fermentation of Soybean Meal Using a Bioreactor
Gabriela L. Vitcosque,Rafael F. Fonseca,Ursula Fabiola Rodríguez-Zúñiga,Victor Bertucci Neto
Enzyme Research , 2012, DOI: 10.1155/2012/248983
Abstract:
Production of Biomass-Degrading Multienzyme Complexes under Solid-State Fermentation of Soybean Meal Using a Bioreactor
Gabriela L. Vitcosque,Rafael F. Fonseca,Ursula Fabiola Rodríguez-Zú?iga,Victor Bertucci Neto,Sonia Couri,Cristiane S. Farinas
Enzyme Research , 2012, DOI: 10.1155/2012/248983
Abstract: Biomass-degrading enzymes are one of the most costly inputs affecting the economic viability of the biochemical route for biomass conversion into biofuels. This work evaluates the effects of operational conditions on biomass-degrading multienzyme production by a selected strain of Aspergillus niger. The fungus was cultivated under solid-state fermentation (SSF) of soybean meal, using an instrumented lab-scale bioreactor equipped with an on-line automated monitoring and control system. The effects of air flow rate, inlet air relative humidity, and initial substrate moisture content on multienzyme (FPase, endoglucanase, and xylanase) production were evaluated using a statistical design methodology. Highest production of FPase (0.55?IU/g), endoglucanase (35.1?IU/g), and xylanase (47.7?IU/g) was achieved using an initial substrate moisture content of 84%, an inlet air humidity of 70%, and a flow rate of 24?mL/min. The enzymatic complex was then used to hydrolyze a lignocellulosic biomass, releasing 4.4?g/L of glucose after 36 hours of saccharification of 50?g/L pretreated sugar cane bagasse. These results demonstrate the potential application of enzymes produced under SSF, thus contributing to generate the necessary technological advances to increase the efficiency of the use of biomass as a renewable energy source. 1. Introduction Biomass-degrading enzymes are one of the most costly inputs affecting the economic viability of the biochemical route for biomass conversion into biofuels. This is due to the large scale of the processes involved in biofuel production, and the considerable quantities of enzymes that are required. In addition to quantity, the quality of the enzymatic complex is an important issue, since a cocktail containing cellulases, hemicellulases, pectinases, and other accessory enzymes, acting in synergy in the degradation process, is necessary due to the high recalcitrance of plant biomass. This enzymatic complex is produced by a wide variety of microorganisms (bacteria and fungi); however, the aerobic fungi are known for their higher growth and protein secretion rates [1, 2]. Most commercial cellulases are produced by filamentous fungi of the genera Trichoderma and Aspergillus [3]. The use of solid-state fermentation (SSF) is particularly advantageous for enzyme production by filamentous fungi, since it simulates the natural habitat of the microorganisms [4]. From the environmental point of view, the main benefit of SSF is the ability to use agroindustrial waste (sugarcane bagasse, wheat bran, soybean meal, etc.) as a solid substrate that
Efectos de la extracción no controlada de madera sobre la comunidad y estructura de tama?os de los manglares de Alvarado, Veracruz, México
Rodríguez-Zú?iga, María Teresa;Ramírez-García, Pedro;Gutiérrez-Granados, Gabriel;
Boletín de la Sociedad Botánica de México , 2011,
Abstract: we analyzed the effects of uncontrolled timber extraction on community and diameter-size of mangroves in alvarado. we sampled 15 sites, gathering data on floristic composition, height, and basal area. changes in diameter-size were evaluated through the size-distribution analysis. avicennia germinans, laguncularia racemosa, and rhizophora mangle were present in the area. structure parameters were similar to others documented in similar latitudes in mexico, but the sites under human influence had shifts in species dominance. the analysis of diameter-size distributions indicated that l. racemosa was underrepresented due to logging, mainly of individuals < 10 cm in diameter. we suggest that current extraction trends threaten the distribution of l. racemosa.
EFECTOS DE LA EXTRACCIóN NO CONTROLADA DE MADERA SOBRE LA COMUNIDAD Y ESTRUCTURA DE TAMA OS DE LOS MANGLARES DE ALVARADO, VERACRUZ, MéXICO
MARíA TERESA RODRíGUEZ-Zú?IGA,PEDRO RAMíREZ-GARCíA,GABRIEL GUTIéRREZ-GRANADOS
Boletín de la Sociedad Botánica de México , 2011,
Abstract: En este trabajo se analizó el efecto de la extracción no controlada de madera sobre la comunidad y estructura de tama os de los manglares de Alvarado. Para realizar ésto se muestrearon 15 sitios de los cuales se obtuvo la composición florística, altura y área basal. Los efectos sobre la estructura de tama os se evaluaron con un análisis de la distribución de individuos por categoría de tallas. Se documentó la presencia de Avicennia germinans, Laguncularia racemosa y Rhizophora mangle. Los parámetros estructurales fueron similares a los registrados en otros manglares de la zona tropical de México; sin embargo, los sitios con mayor influencia humana presentan cambios en la dominancia de especies. El análisis por categoría de tama os indica que L. racemosa tiene problemas de regeneración debido principalmente a la extracción de individuos < 10 cm de diámetro de tallo. Los datos sugieren que de continuar con la extracción actual de tallos de L. racemosa, la situación local de la especie puede estar en riesgo.
CARACTERIZACIóN DE PLAYAS DE ANIDACIóN Y ZONAS DE ALIMENTACIóN DE TORTUGAS MARINAS EN EL ARCHIPIéLAGO DE SAN BERNARDO, CARIBE COLOMBIANO
Rincón-Díaz,Martha Patricia; Rodríguez-Zárate,Clara Jimena;
Boletín de Investigaciones Marinas y Costeras - INVEMAR , 2004,
Abstract: the san bernardo archipelago, in the colombian caribbean zone, is well recognized for being a sporadic nesting and feeding area for the green, hawksbill and loggerhead turtles. due to the fact that the san bernardo archipelago has outstanding coral areas, marine grasses and sandy beaches and their environmental offers for the marine turtles have not been described yet, it was opportune to carry out this study between july and october of 2002. thus, this research tends to fill this gap by describing the nesting beaches and feeding areas according to their geomorphologic and biotic aspects and, for the later areas, some oceanographic aspects too. seven potential nesting beaches and 20 stations on feeding areas were evaluated to identify natural and anthropogenic threats that could affect sea turtles and their habitats. the only species that still nests on these islands is the hawksbill turtle, but its nesting areas are being reduced because of erosion and constructions on the beach. the remaining nesting places observed during the 2002 season were on the southeastern side of palma island and on the northern side of tintipán island. in the feeding areas, the majority of stations (n=14) have marine grass with predominance of soft bottom. from these characterizations in the feeding areas, nine sponges and two seaweeds species were described as index species hawksbill turtles feed on. in order to gather information about the marine turtles diet components, five stomach contents of hawskbill turtle and six of green turtle were analyzed. they showed that the sponges eicionemia sp. and geodia sp. are the principal diet components (96% dry weight) in the hawksbill turtle diet. in the case of the green turtle, thalassia testudinum and syringodium filiforme grasses were identified as index species (98% dry weight); they were the most common during the field observations. the principal threat for sea turtles was the direct capture of adults and juveniles in feeding areas, for wh
TAC multicorte y arteritis de Takayasu Multiple slices CT scan and Takayasu arteritis
Elías Forero,Antonio Iglesias,Eduardo Zú?iga Rodríguez
Acta Medica Colombiana , 2006,
Abstract:
Effect of Inoculation with Three Phytohormone Producers Phytobacteria with ACC Deaminase Activity on Root Length of Lens esculenta Seedlings  [PDF]
Natalia Elenes Zazueta, Orlando Ortega Acosta, Laura Martínez Herrera, Raúl Alcalde Vázquez, Eugenia López López, Angelica Guerrero Zú?iga, Angelica Rodríguez Dorantes
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.411273
Abstract: Plant-associated bacteria that inhabit the rhizosphere may influence the plant growth by their contribution to the endogenous pool of phytohormones and by the activity of ACC deaminase to decrease the ethylene concentration. The aim of this study was to analyse the root length growth by the promoting effect of indole acetic acid producers phytobacteria with ACC deaminase activity, on inoculated seeds of Lens esculenta as synergistic effect on root elongation. In this study, although the roots of L. esculenta seedlings do not show a significant promotion, these phytobacteria could be recommended to treat plants analyzing their added inoculum to increase plant biomass and retard the effect of ethylene on cultures supplied with Tryptophan and ACC.
Retinoblastoma: revisión y reporte de un caso
Rodríguez Rodríguez,Carlos; Romero Cubero,David; Zú?iga Arias,Pedro; Picado Rodríguez,Luis Alonso;
Acta Pediátrica Costarricense , 2003,
Abstract: los autores presentan el caso de un paciente de 2 a?os con historia de ser portador de retinoblastoma bilateral diagnosticado en octubre del 2001. recibió n° 6 ciclos de quimioterapia y no hubo respuesta adecuada. fue tratado con cirugía láser en colombia y luego recibió no2 ciclos más de quimioterapia. actualmente consulta por tumoración en ojo izquierdo. se le realiza tac de órbita que muestra masa de tejidos blandos que proyecta el globo ocular hacia adelante y persistencia de calcificaciones previas
The herbicides dalapon and diuron tested for genotoxicity in Drosophila melanogaster
Rosario Rodríguez Arnaiz,Patricia Ramos Morales,Juan Carlos Gaytán Oyarzún,Dora Lydia Rodríguez Zú?iga
Revista internacional de contaminación ambiental , 1989,
Abstract: Se evaluaron los efectos genotóxicos de los herbicidas dalapón y diurón, ampliamente usados en México. Para ambos compuestos se analizó la inducción de mutaciones letales recesivas ligadas al sexo. La prueba de pérdida de cromosomas sexuales, utilizando un sistema deficiente en reparación, se corrió solamente para el diurón. Bajo las condiciones experimentales el dalapón ~esultó negativo y el diurón positivo en el estudio de letales recesivos. Los resultados obtenidos en la prueba que mide la pCrdida de los cromosomas sexuales son negativos. No hay indicación de efectos verdaderamente genotóxicos del diurón en este ensayo.
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