Purification and characterization of a thermostable cellulase-free xylanase from the newly isolated Paecilomyces themophila

• Published in: Enzyme and microbial technology Vol. 38; no. 6; pp. 780 - 787
• Main Authors: Li, Lite, Tian, Hongmei, Cheng, Yongqiang, Jiang, Zhengqiang, Yang, Shaoqing
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.04.2006; Elsevier Science
• Subjects: Biological and medical sciences; Biotechnology; Characterization; Fundamental and applied biological sciences. Psychology; Glycoprotein; Paecilomyces; Paecilomyces themophila; Purification; Thermostable; Xylanase; MOPS; Purification; Glycoprotein; DNS; TLC; CHES; EDTA; PDA; PVDF; Characterization; BSA; SDS-PAGE; Xylanase; CMC; Thermostable; Paecilomyces themophila; CAPS; Paecilomyces themophila: Purification; Enzyme; Endo-1,4-β-xylanase; Thermal stability; Fungi; Paecilomyces; Glycosidases; Hydrolases; Fungi Imperfecti; O-Glycosidases; Thallophyta
• ISSN: 0141-0229; 1879-0909
• DOI: 10.1016/j.enzmictec.2005.08.007

The newly isolated thermophilic fungus, Paecilomyces themophila J18, when grown on a medium containing corncob (4%, w/v) at 50 °C for 5 days, produced 1470 U ml −1 of xylanase. Xylanase was purified 2.4-fold to homogeneity with a recovery yield of 38.3%. It appeared as a single protein band on SDS-PAGE gel with a molecular mass of approximately 25.8 kDa. The xylanase was a glycoprotein with a neutral carbohydrate content of 21.0%. It had an optimum pH of 7.0, and was stable over pH 6.0–11.0. The optimal temperature of the xylanase was 75–80 °C and it was stable up to 75 °C at pH 7.0. Apparent K m values of the xylanase for birchwood, beechwood, soluble and insoluble oat-spelt xylans were 1.6, 2.4, 2.0 and 11.8 mg ml −1, respectively. The xylanase hydrolyzed beechwood xylan and xylooligosaccharides to yield mainly xylotriose and xylobiose as end products, suggesting it is an endo-xylanase. This is the first report on the purification and characterization of a thermostable xylanase from Paecilomyces themophila. These findings in this study have great implications for the future applications of the xylanase.