title: Identification of thermostable beta-xylosidase activities produced by Aspergillus brasiliensis and Aspergillus niger.
abstract: Twenty Aspergillus strains were evaluated for production of extracellular cellulolytic and xylanolytic activities. Aspergillus brasiliensis, A. niger and A. japonicus produced the highest xylanase activities with the A. brasiliensis and A. niger strains producing thermostable beta-xylosidases. The beta-xylosidase activities of the A. brasiliensis and A. niger strains had similar temperature and pH optima at 75 degrees C and pH 5 and retained 62% and 99%, respectively, of these activities over 1 h at 60 degrees C. At 75 degrees C, these values were 38 and 44%, respectively. Whereas A. niger is a well known enzyme producer, this is the first report of xylanase and thermostable beta-xylosidase production from the newly identified, non-ochratoxin-producing species A. brasiliensis.
authors.affiliation: Bioprocess Engineering, Department of Chemical Engineering, Technical University of Denmark, Building 229, 2800, Kgs. Lyngby, Denmark.
authors.forename: Mads
authors.initials: M
authors.lastname: Pedersen
authors.forename: Henrik Klitgaard
authors.initials: HK
authors.lastname: Lauritzen
authors.forename: Jens Christian
authors.initials: JC
authors.lastname: Frisvad
authors.forename: Anne S
authors.initials: AS
authors.lastname: Meyer
mesh_terms: D001230:Aspergillus / Q000201:enzymology*; D001234:Aspergillus niger / Q000201:enzymology*; D002482:Cellulose / Q000378:metabolism; D004043:Dietary Fiber / Q000378:metabolism; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D013379:Substrate Specificity; D013696:Temperature; D013997:Time Factors; D014990:Xylans / Q000378:metabolism; D014995:Xylosidases / Q000378:metabolism*
chemical_list: D004043:Dietary Fiber; D014990:Xylans; D002482:Cellulose; C085118:arabinoxylan; D014995:Xylosidases; C026579:exo-1,4-beta-D-xylosidase