Consulta: creatorFacets:"Hours,Roque Alberto"
Registros recuperados: 5
Data/hora: 12/06/2024 17:16:17

Role of PPase-SE in Geotrichum klebahnii, a yeast-like fungus able to solubilize pectin
Provedor de dados: Electronic Journal of Biotechnology
Autores: Rojas,Natalia Lorena; Cavalitto,Sebastián Fernando; Mignone,Carlos Fernando; Hours,Roque Alberto.
Protopectinases (PPases) constitute a heterogeneous group of extracellular enzymes able to release soluble pectin from insoluble protopectin in plant tissues. Geotrichum klebahnii (ATCC 42397) produces PPase-SE with endopolygalacturonase activity. PPase-SE has been used for pectin extraction and maceration of plant tissues. Here, the capacity of G. klebahnii to use different pectins as carbon and energy sources (CES) was studied, in addition to PPase-SE capacity to release pectin from lemon peel. The strain was unable to use pectin from different origins as CES. When G. klebahnii was cultivated with mixtures of different amounts of glucose and citrus pectin as CES, the biomass obtained was proportional to the initial concentration of glucose, which was...
Tipo: Journal article
Palavras-chave: Carbon balance; Enzymatic pectin extraction; Microbial pectin utilization; Pectinases; Synthetic medium.
Ano: 2008
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582008000100012

Biotechnological processes for chitin recovery out of crustacean waste: A mini-review
Provedor de dados: Electronic Journal of Biotechnology
Autores: Gortari,María Cecilia; Hours,Roque Alberto.
Background: Chitin is an important natural resource. The annual worldwide production is estimated in approximately 10(10)-10(12) ton. It is produced by arthropods (insects and crustaceans), molluscs and fungi. Its main biological function is structural. Crustacean shells are the most important chitin source for commercial use due to its high content and ready availability. Chitin and its derivatives have great economical value because of their numerous applications: food, cosmetics, pharmaceuticals, textile industries, waste water treatment and agriculture. In nature, chitin is closely associated with proteins, minerals, lipid and pigments, which have to be removed. Results: Several techniques to extract chitin from different sources have been reported....
Tipo: Journal article
Palavras-chave: Biological extraction; Chitin production; Crustacean waste.
Ano: 2013
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582013000300014

Aspergillus kawachii produces an inulinase in cultures with yacon (Smallanthus sonchifolius) as substrate
Provedor de dados: Electronic Journal of Biotechnology
Autores: Chesini,Mariana; Neila,Lorena Paola; de la Parra,Dante Fratebianchi; Rojas,Natalia Lorena; Contreras Esquivel,Juan Carlos; Cavalitto,Sebastian Fernando; Ghiringhelli,Pablo Daniel; Hours,Roque Alberto.
Background: Inulinases have been extracted and characterized from inulin-storing tissues; however, production of microbial inulinases have recently draw much attention as they offer several industrial advantages. Many microorganisms, including filamentous fungi, yeast and bacteria have been claimed as inulinase producers. These hydrolases are usually inducible and their exo-acting forms may hydrolyze fructose polymers (inulin) and oligosaccharides such as sucrose and raffinose. Fungal inulinase extracts are often produced as stable mixture of highly active fructanhydrolases. From a practical prospective, the best known inulinases to date are those produced by species of Penicillium, Aspergillus and Kluyveromyces. Results: The production of extracellular...
Tipo: Journal article
Palavras-chave: Acidophilic enzymes; Batch cultures; Inulin degradation; Submerged cultures.
Ano: 2013
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582013000300008

Extracellular enzymes of Fusarium graminearum isolates
Provedor de dados: Brazilian Archives of Biology and Technology
Autores: Kikot,Gisele Eleonora; Hours,Roque Alberto; Alconada,Teresa María.
Fusarium graminearum isolates from three different agroecological regions in Argentina were examined according to the production of different extracellular enzyme activities of potential biotechnological interest: pectinases (PGase: polygalacturonase and PMGase: polymethylgalacturonase), cellulase (CMCase: carboxymethylcellulase) and hemicellulase (xylanase). The isolates were grown in minimum salt medium supplemented with 0.25% glucose, 0.125% citric pectin and 0.125% oat bran as carbon sources and/or enzyme inducers. PGase activity was detected early (after two days of incubation) in all the cultures; it was found to be the highest for all the isolates. PMGase was high only for those isolates of the II region. CMCase and endoxylanase activities were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Extracellular enzymes; Fusarium graminearum; Pectinases; Cellulases; Hemicellulases.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132010000400005

Purification and Characterization of a Polygalacturonase Produced by Wickerhamomyces anomalus
Provedor de dados: Brazilian Archives of Biology and Technology
Autores: Martos,María Alicia; Butiuk,Ana Paula; Rojas,Natalia Lorena; Hours,Roque Alberto.
The aim of this work was to study the purification and physicochemical properties of an endo-polygalacturonase (PG) produced by Wickerhamomyces anomalus isolated from the citrus fruit peels. The enzyme was purified to homogeneity from the culture filtrate of W. anomalus grown on the yeast nitrogen base medium with glucose as carbon and energy source and citrus pectin as inductor. After anion-exchange chromatography and gel filtration chromatography, PG activity was eluted as a single peak, yielding 21% of the original activity. After dialysis and cation-exchange chromatography, only one fraction with PG activity was obtained, recovering 56% of initial enzyme activity and 1.3-fold increase in specific activity. The molecular weight of the enzyme was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Wickerhamomyces anomalus; Polygalacturonase; Purification; Characterization.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132014000400587