A new xylanase from a Trichoderma harzianum strain.
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.
de Paula Silveira
F Q
FQ
Laboratório de Enzimologia, Departamento de Biologia Celular, Universidade de Brasília, Brasília, DF, CEP 70910-900, Brazil.
Sousa
M V
MV
Ricart
C A
CA
Milagres
A M
AM
de Medeiros
C L
CL
Filho
E X
EX
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
D000596:Amino Acids; D014995:Xylosidases; D043325:Xylan Endo-1,3-beta-Xylosidase