title: A new xylanase from a Trichoderma harzianum strain.
abstract: A new xylanase (XYL2) was purified from solid-state cultures of Trichoderma harzianum strain C by ultrafiltration and gel filtration. SDS-PAGE of the xylanase showed an apparent homogeneity and molecular weight of 18 kDa. It had the highest activity at pH 5.0 and 45 degrees C and was stable at 50 degrees C and pH 5.0 up to 4 h xylanase. XYL2 had a low Km with insoluble oat spelt xylan as substrate. Compared to the amino acid composition of xylanases from Trichoderma spp, xylanase XYL2 presented a high content of glutamate/glutamine, phenylalanine and cysteine, and a low content of serine. Xylanase XYL2 improved the delignification and selectivity of unbleached hardwood kraft pulp.
authors.affiliation: Laboratório de Enzimologia, Departamento de Biologia Celular, Universidade de Brasília, Brasília, DF, CEP 70910-900, Brazil.
authors.forename: F Q
authors.initials: FQ
authors.lastname: de Paula Silveira
authors.forename: M V
authors.initials: MV
authors.lastname: Sousa
authors.forename: C A
authors.initials: CA
authors.lastname: Ricart
authors.forename: A M
authors.initials: AM
authors.lastname: Milagres
authors.forename: C L
authors.initials: CL
authors.lastname: de Medeiros
authors.forename: E X
authors.initials: EX
authors.lastname: Filho
mesh_terms: D000596:Amino Acids / Q000032:analysis; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D008970:Molecular Weight; D014242:Trichoderma / Q000201:enzymology*; D014462:Ultrafiltration; D014934:Wood; D043325:Xylan Endo-1,3-beta-Xylosidase; D014995:Xylosidases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D000596:Amino Acids; D014995:Xylosidases; D043325:Xylan Endo-1,3-beta-Xylosidase