title: Characterization and biotechnological application of recombinant xylanases from Aspergillus nidulans.
abstract: Two xylanases from Aspergillus nidulans, XlnB and XlnC, were expressed in Pichia pastoris, purified and characterized. XlnB and XlnC achieved maximal activities at 60°C and pH 7.5 and at 50°C and pH 6.0, respectively. XlnB showed to be very thermostable by maintaining 50% of its original activity after 49h incubated at 50°C. XlnB had its highest activity against wheat arabinoxylan while XlnC had the best activity against beechwood xylan. Both enzymes were completely inhibited by SDS and HgCl2. Xylotriose at 1mg/ml also totally inibited XlnB activity. TLC analysis showed that the main product of beechwood xylan hydrolysis by XlnB and XlnC was xylotetraose. An additive effect was shown between XlnB and XlnC and the xylanases of two tested commercial cocktails. Sugarcane bagasse saccharification results showed that these two commercial enzymatic cocktails were able to release more glucose and xylose after supplementation with XlnB and XlnC.
authors.affiliation: Department of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, MG, Brazil; Fungal Physiology, CBS-KNAW Fungal Biodiversity Centre & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands. Electronic address: gabmaitan@yahoo.com.br.
authors.forename: Gabriela P
authors.initials: GP
authors.lastname: Maitan-Alfenas
authors.affiliation: Department of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, MG, Brazil; Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
authors.forename: Mariana B
authors.initials: MB
authors.lastname: Oliveira
authors.affiliation: Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
authors.forename: Ronaldo A P
authors.initials: RA
authors.lastname: Nagem
authors.affiliation: Fungal Physiology, CBS-KNAW Fungal Biodiversity Centre & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands.
authors.forename: Ronald P
authors.initials: RP
authors.lastname: de Vries
authors.affiliation: Department of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, MG, Brazil.
authors.forename: Valéria M
authors.initials: VM
authors.lastname: Guimarães
mesh_terms: D001233:Aspergillus nidulans / Q000201:enzymology* / Q000235:genetics; D001709:Biotechnology; D002482:Cellulose / Q000378:metabolism; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D010843:Pichia / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D031786:Saccharum / Q000737:chemistry; D013696:Temperature
chemical_list: D011994:Recombinant Proteins; D002482:Cellulose; C027433:bagasse; D043364:Endo-1,4-beta Xylanases
keywords: Aspergillus nidulans; Pichia pastoris; Saccharification; Sugarcane bagasse; Xylanase