A novel thermoacidophilic family 10 xylanase from Penicillium pinophilum C1

Article abstract of DOI:10.1016/j.procbio.2011.09.018

A novel endo-β-1,4-xylanase gene (xyn10C1) was cloned from Penicillium pinophilum C1 and overexpressed in Pichia pastoris. The 1071-bp full-length gene encodes a 356-residue polypeptide containing the catalytic domain of glycoside hydrolase 10. Deduced XYN10C1 shares highest amino acid sequence identity of 49.3% with a putative xylanase from Glomeella graminicola M1.001. Purified recombinant XYN10C1 showed maximal activity at pH 4.0-5.5 and 75 °C, exhibited good adaptability to broad acidic pH and temperature ranges (>69.0% activity at pH 2.5-6.5; and >91.0% activity at 70-80 °C and 22.2% even at 90 °C), and was highly stable at pH 2.0-7.0 for 1 h at 37 °C. The specific activity, K_m and V_max values for birchwood xylan and soluble wheat arabinoxylan were 100.7 and 137.4 U/mg, 4.3 and 6.9 mg/ml, and 195.4 and 209.3 μmol/min/mg, respectively. The enzyme was strongly resistant to most metal ions and proteases (pepsin and trypsin). Under simulated mashing conditions, addition of XYN10C1 (80 U) to the brewery mash (12.5 g in 50 ml system) significantly increased the filtration rate by 26.7% and reduced the viscosity by 9.8%, respectively. All these favorable enzymatic properties make XYN10C1 attractive for potential applications in the food and animal feed industries.