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1.
J Basic Microbiol ; 54(5): 333-9, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-23681744

RESUMEN

This study investigates the production of glucoamylase from Aspergillus phoenicis in Machado Benassi (MB) medium using 1% maltose as carbon source. The maximum amylase activity was observed after four days of cultivation, on static conditions at 30 °C. Glucoamylase production was induced by maltose and inhibited by different glucose concentrations. The optimum of temperature and pH were 60-65 °C, and 4.5 or 5.0 to sodium acetate and Mcllvaine buffers, respectively. It was observed that the enzyme was totally stable at 30-65 °C for 1 h, and the pH range was 3.0-6.0. The enzyme was mainly activated by manganese (176%), and calcium (130%) ions. The products of starch hydrolysis were analyzed by thin layer chromatography and after 3 h, only glucose was detected, characterizing the amylolytic activity as a glucoamylase.


Asunto(s)
Aspergillus/enzimología , Aspergillus/crecimiento & desarrollo , Calcio/metabolismo , Activadores de Enzimas/metabolismo , Glucano 1,4-alfa-Glucosidasa/aislamiento & purificación , Glucano 1,4-alfa-Glucosidasa/metabolismo , Manganeso/metabolismo , Cromatografía en Capa Delgada , Medios de Cultivo/química , Inhibidores Enzimáticos/metabolismo , Fermentación , Glucosa/metabolismo , Concentración de Iones de Hidrógeno , Hidrólisis , Maltosa/metabolismo , Acetato de Sodio/metabolismo , Almidón/metabolismo , Temperatura
2.
Enzyme Res ; 2013: 324061, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24455209

RESUMEN

A protein extract containing a plant lipase from oleaginous seeds of Pachira aquatica was tested using soybean oil, wastewater from a poultry processing plant, and beef fat particles as substrate. The hydrolysis experiments were carried out at a temperature of 40°C, an incubation time of 90 minutes, and pH 8.0-9.0. The enzyme had the best stability at pH 9.0 and showed good stability in the alkaline range. It was found that P. aquatica lipase was stable in the presence of some commercial laundry detergent formulations, and it retained full activity up to 0.35% in hydrogen peroxide, despite losing activity at higher concentrations. Concerning wastewater, the lipase increased free fatty acids release by 7.4 times and promoted the hydrolysis of approximately 10% of the fats, suggesting that it could be included in a pretreatment stage, especially for vegetable oil degradation.

3.
Bioprocess Biosyst Eng ; 34(3): 347-55, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21046416

RESUMEN

Solid-state fermentation obtained from different and low-cost carbon sources was evaluated to endocellulases and endoxylanases production by Aspergillus japonicus C03. Regarding the enzymatic production the highest levels were observed at 30 °C, using soy bran added to crushed corncob or wheat bran added to sugarcane bagasse, humidified with salt solutions, and incubated for 3 days (xylanase) or 6 days (cellulase) with 70% relative humidity. Peptone improved the xylanase and cellulase activities in 12 and 29%, respectively. The optimum temperature corresponded to 60 °C and 50-55 °C for xylanase and cellulase, respectively, both having 4.0 as optimum pH. Xylanase was fully stable up to 40 °C, which is close to the rumen temperature. The enzymes were stable in pH 4.0-7.0. Cu++ and Mn++ increased xylanase and cellulase activities by 10 and 64%, respectively. A. japonicus C03 xylanase was greatly stable in goat rumen fluid for 4 h during in vivo and in vitro experiments.


Asunto(s)
Aspergillus/enzimología , Celulasa/biosíntesis , Celulasa/química , Endo-1,4-beta Xilanasas/biosíntesis , Endo-1,4-beta Xilanasas/química , Aditivos Alimentarios , Alimentación Animal , Animales , Aspergillus/metabolismo , Carbono/metabolismo , Celulasa/metabolismo , Endo-1,4-beta Xilanasas/metabolismo , Estabilidad de Enzimas , Fermentación , Proteínas Fúngicas/biosíntesis , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Cabras , Concentración de Iones de Hidrógeno , Microbiología Industrial , Residuos Industriales/análisis , Nitrógeno/metabolismo , Nitrógeno/provisión & distribución , Rumen/enzimología , Rumen/metabolismo , Rumiantes , Temperatura
4.
J Microbiol ; 48(3): 331-6, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20571951

RESUMEN

Thermophilic fungi produce thermostable enzymes which have a number of applications, mainly in biotechnological processes. In this work, we describe the characterization of a protease produced in solidstate (SSF) and submerged (SmF) fermentations by a newly isolated thermophilic fungus identified as a putative new species in the genus Myceliophthora. Enzyme-production rate was evaluated for both fermentation processes, and in SSF, using a medium composed of a mixture of wheat bran and casein, the proteolytic output was 4.5-fold larger than that obtained in SmF. Additionally, the peak of proteolytic activity was obtained after 3 days for SSF whereas for SmF it was after 4 days. The crude enzyme obtained by both SSF and SmF displayed similar optimum temperature at 50 degrees C, but the optimum pH shifted from 7 (SmF) to 9(SSF). The alkaline protease produced through solid-state fermentation (SSF), was immobilized on beads of calcium alginate, allowing comparative analyses of free and immobilized proteases to be carried out. It was observed that both optimum temperature and thermal stability of the immobilized enzyme were higher than for the free enzyme. Moreover, the immobilized enzyme showed considerable stability for up to 7 reuses.


Asunto(s)
Proteínas Bacterianas/metabolismo , Endopeptidasas/metabolismo , Proteínas Fúngicas/metabolismo , Sordariales/enzimología , Alginatos , Proteínas Bacterianas/aislamiento & purificación , Endopeptidasas/aislamiento & purificación , Estabilidad de Enzimas , Enzimas Inmovilizadas/metabolismo , Fermentación , Proteínas Fúngicas/aislamiento & purificación , Ácido Glucurónico , Ácidos Hexurónicos , Concentración de Iones de Hidrógeno , Cinética , Filogenia , Sordariales/clasificación , Sordariales/genética , Sordariales/aislamiento & purificación , Temperatura
5.
Appl Biochem Biotechnol ; 150(3): 233-42, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18682900

RESUMEN

A new lipase from seeds of Pachira aquatica was purified to homogeneity by SDS-PAGE obtaining an enzyme with a molecular weight of approximately 55 kDa. The purified lipase exhibited maximum activity at 40 degrees C and pH 8.0, for an incubation time of 90 min. Concerning temperature stability, at the range from 4 to 50 degrees C, it retained approximately 47% of its original activity for 3 h. The enzyme activity increased in the presence of Ca(++) and Mg(++), but was inhibited by Hg(++), Mn(++), Zn(++), Al(+++) and various oxidizing and reducing agents. The lipase was highly stable in the presence of organic solvents, and its activity was stimulated by methanol. The values of K(m) and V(max) were 1.65 mM and 37.3 micromol mL(-1) min(-1), respectively, using p-nitrophenylacetate as substrate. The enzyme showed preference for esters of long-chain fatty acids, but demonstrated significant activity against a wide range of substrates.


Asunto(s)
Bombacaceae/enzimología , Lipasa/metabolismo , Proteínas de Plantas/metabolismo , Semillas/enzimología , Calcio/farmacología , Electroforesis en Gel de Poliacrilamida , Activación Enzimática/efectos de los fármacos , Estabilidad de Enzimas/efectos de los fármacos , Concentración de Iones de Hidrógeno , Cinética , Lipasa/química , Lipasa/aislamiento & purificación , Magnesio/farmacología , Manganeso/farmacología , Mercurio/farmacología , Metanol/farmacología , Peso Molecular , Proteínas de Plantas/química , Proteínas de Plantas/aislamiento & purificación , Solventes/farmacología , Especificidad por Sustrato , Temperatura , Zinc/farmacología
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