title: Efficient production of lignocellulolytic enzymes xylanase, β-xylosidase, ferulic acid esterase and β-glucosidase by the mutant strain Aspergillus awamori 2B.361 U2/1.
abstract: The production of xylanase, β-xylosidase, ferulic acid esterase and β-glucosidase by Aspergillus awamori 2B.361 U2/1, a hyper producer of glucoamylase and pectinase, was evaluated using selected conditions regarding nitrogen nutrition. Submerged cultivations were carried out at 30 °C and 200 rpm in growth media containing 30 g wheat bran/L as main carbon source and either yeast extract, ammonium sulfate, sodium nitrate or urea, as nitrogen sources; in all cases it was used a fixed molar carbon to molar nitrogen concentration of 10.3. The use of poor nitrogen sources favored the accumulation of xylanase, β-xylosidase and ferulic acid esterase to a peak concentrations of 44,880; 640 and 118 U/L, respectively, for sodium nitrate and of 34,580, 685 and 170 U/L, respectively, for urea. However, the highest β-glucosidase accumulation of 10,470 U/L was observed when the rich organic nitrogen source yeast extract was used. The maxima accumulation of filter paper activity, xylanase, β-xylosidase, ferulic acid esterase and β-glucosidase by A. awamori 2B.361 U2/1 was compared to that produced by Trichoderma reesei Rut-C30. The level of β-glucosidase was over 17-fold higher for the Aspergillus strain, whereas the levels of xylanase and β-xylosidase were over 2-fold higher. This strain also produced ferulic acid esterase (170 U/L), which was not detected in the T. reesei culture.
authors.affiliation: Bioprocess Laboratory, Embrapa Food Technology, Rio de Janeiro, RJ, Brazil.
authors.forename: Leda Maria Fortes
authors.initials: LM
authors.lastname: Gottschalk
authors.forename: Raquel
authors.initials: R
authors.lastname: de Sousa Paredes
authors.forename: Ricardo Sposina Sobral
authors.initials: RS
authors.lastname: Teixeira
authors.forename: Ayla Sant'Ana
authors.initials: AS
authors.lastname: da Silva
authors.forename: Elba Pinto
authors.initials: EP
authors.lastname: da Silva Bon
mesh_terms: D001230:Aspergillus / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D002244:Carbon / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D009584:Nitrogen / Q000378:metabolism; D013696:Temperature; D014995:Xylosidases / Q000378:metabolism*; D001617:beta-Glucosidase / Q000378:metabolism*
chemical_list: D003470:Culture Media; D002244:Carbon; D002265:Carboxylic Ester Hydrolases; C070196:feruloyl esterase; D014995:Xylosidases; D001617:beta-Glucosidase; D009584:Nitrogen
keywords: Aspergillus awamori 2B.361 U2/1; cellulases; hemicellulases; nitrogen nutrition; β-glucosidase