Publicação: Purification and characterization of xylanases from Aspergillus giganteus
Nenhuma Miniatura disponível
Data
2004-04-20
Autores
Orientador
Coorientador
Pós-graduação
Curso de graduação
Título da Revista
ISSN da Revista
Título de Volume
Editor
Tipo
Artigo
Direito de acesso
Acesso restrito
Resumo
A strain of Aspergillus giganteus cultivated in a medium with xylan produced two xylanases (xylanase I and II) which were purified to homogeneity. Their molar mass, estimated by SDS-PAGE, were 21 and 24 kDa, respectively. Both enzymes are glycoproteins with 50°C temperature optimum; optimum pH was 6.0-6.5 for xylanase I and 6.0 for xylanase II. At 50°C xylanase I exhibited higher thermostability than xylanase II. Hg2+, Cu 2+ and SDS were strong inhibitors, 1,4-dithiothreitol stimulated the reaction of both enzymes. Both xylanases are xylan-specific; kinetic parameters indicated higher efficiency in the hydrolysis of oat spelts xylan. In hydrolysis of this substrate, xylotriose, xylotetraose and larger xylooligosaccharides were released and hence the enzymes were classified as endoxylanases.
Descrição
Palavras-chave
ammonium sulfate, copper, dextran, dithiothreitol, dodecyl sulfate sodium, endo 1,4 beta xylanase, enzyme activator, enzyme inhibitor, fungal protein, glycoprotein, mercury derivative, sephadex, xylan, Aspergillus, chemistry, culture medium, enzyme specificity, enzyme stability, enzymology, gel chromatography, growth, development and aging, isolation and purification, kinetics, metabolism, molecular weight, pH, polyacrylamide gel electrophoresis, precipitation, temperature, Ammonium Sulfate, Chromatography, Gel, Copper, Culture Media, Dextrans, Dithiothreitol, Electrophoresis, Polyacrylamide Gel, Endo-1,4-beta Xylanases, Enzyme Activators, Enzyme Inhibitors, Enzyme Stability, Fractional Precipitation, Fungal Proteins, Glycoproteins, Hydrogen-Ion Concentration, Kinetics, Mercury Compounds, Molecular Weight, Sodium Dodecyl Sulfate, Substrate Specificity, Temperature, Xylans, Aspergillus giganteus
Idioma
Inglês
Como citar
Folia Microbiologica, v. 49, n. 1, p. 13-18, 2004.
