Cloning, expression and characterization of a novel acidic xylanase, XYL11B, from the acidophilic fungus Bispora

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• 作者：Huiying Luo ; Yaru Wang ; Jiang Li ; Hui wang ; Jun Yang ; Yuhui Yang ; Huoqing Huang ; Yunliu Fan ; Bin Yao
• 关键词：Acidophilic xylanase ; Acidophilic fungus ; Bispora sp. MEY-1 ; Overexpression ; Pichia pastoris
• 刊名：Enzyme and Microbial Technology
• 出版年：2009
• 出版时间：7 August 2009
• 年：2009
• 卷：45
• 期：2
• 页码：126-133
• 全文大小：1240 K

文摘

A xylanase gene (xyl11B) was cloned from Bispora sp. MEY-1 and expressed in Pichia pastoris. xyl11B, with a 66-bp intron, encodes a mature protein of 219 residues with highest identity (57.1 % ) to the Trichoderma reesei xylanase of glycoside hydrolase family 11. The purified recombinant XYL11B was acidophilic, exhibiting maximum activity at pH 2.6 and 65 °C. The enzyme was also thermostable, pH stable, and was highly resistant to both pepsin and trypsin, suggesting good performance in the digestive tract as a feed supplement to improve animal nutrition. The activity of XYL11B was enhanced by most metal ions but was inhibited weakly by Hg²⁺, Pb²⁺and Cu²⁺, which strongly inhibit many other xylanases. The specific activity of XYL11B for oat spelt xylan substrate was 2049 U mg⁻¹. The main hydrolysis products of xylan were xylose and xylobiose.