Stability and chemical modification of xylanase from Aspergillus sp. (2M1 strain).
The 2M1 strain of Aspergillus sp., which showed high extracellular xylanolytic activities in a pre-screening, was studied. Oat-spelt, birch, eucalyptus and pine xylans were used as xylanolytic inductors. The following activities were found at 50 degrees C in the presence of 1% xylan: 120 units/ml (oat-spelt xylan), 132 units/ml (birch xylan), 107 units/ml (eucalyptus xylan), 67 units/ml (pine xylan) and 137 units/ml (larch-wood xylan). Xylanase induced by pine xylan exhibited a higher stability than those induced by the other xylans. The stability was improved by addition of glycerol. In the crude extract, reagents which were found to affect xylanase activity were 1-ethyl-3-(3-dimethylaminopropyl)carbodi-imide for amidation of carboxylic groups and N-bromosuccinimide at a concentration of 0.5 mM for indole oxidation. Methylene Blue, butane-2,3-dione, N-acetylimidazole, chloramine-T and iodoacetate had little effect on the enzyme activity (more than 97% of the original activity remained).
Angelo
R
R
Instituto de Quimica, Universidade Estadual de Campinas, S.P., Brazil.
Aguirre
C
C
Curotto
E
E
Esposito
E
E
Fontana
J D
JD
Baron
M
M
Milagres
A M
AM
Durán
N
N
D001230:Aspergillus / Q000201:enzymology*; D002850:Chromatography, Gel; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D013696:Temperature; D043325:Xylan Endo-1,3-beta-Xylosidase; D014995:Xylosidases / Q000737:chemistry* / Q000302:isolation & purification
D014995:Xylosidases; D043325:Xylan Endo-1,3-beta-Xylosidase