Folia Microbiologica

, Volume 49, Issue 1, pp 13–18

Purification and characterization of xylanases fromAspergillus giganteus

Article

DOI: 10.1007/BF02931639

Cite this article as:
Fialho, M.B. & Carmona, E.C. Folia Microbiol (2004) 49: 13. doi:10.1007/BF02931639

Abstract

A strain ofAspergillus giganteus cultivated in a medium with xylan produced two xylanases (xylanase I and II) which were purified to homogeneity. Their molar mass, estimated by SDS-PAGE, were 21 and 24 kDa, respectively. Both enzymes are glycoproteins with 50 °C temperature optimum; optimum pH was 6.0–6.5 for xylanase I and 6.0 for xylanase II. At 50 °C xylanase I exhibited higher thermostability than xylanase II. Hg2+, Cu2+ and SDS were strong inhibitors, 1,4-dithiothreitol stimulated the reaction of both enzymes. Both xylanases are xylan-specific; kinetic parameters indicated higher efficiency in the hydrolysis of oat spelts xylan. In hydrolysis of this substrate, xylotriose, xylotetraose and larger xylooligosaccharides were released and hence the enzymes were classified as endoxylanases.

Copyright information

© Institute of Microbiology, Academy of Sciences of the Czech Republic 2004

Authors and Affiliations

  1. 1.Departmento de Bioquímica e Microbiologia. Instituto de BiociênciasUNESPRio Claro, São PauloBrazil