Discipline: Animal Science
Xylanases from eight different commercial preparations that were produced from Trichoderma, Aspergillus or Penicillium species were characterized. Xylanase activity ranged from 76 to 30,873 U/g solid. The optimum temperature of xylanase was 60°C from Trichoderma sp and Aspergillus sp, and 50°C for Penicillium sp. The optimum pH for xylanase activity of the three species was at pH 4 or 5.3. In general, the enzymes were resistant to pepsin (550 U/ml) and trypsin (9300 U/ml) degradation. However, the xylanases were thermally stable after 20 seconds exposure up to 70°C only.