An Acidophilic and Acid-Stable β-Mannanase from Phialophora sp. P13 with High Mannan Hydrolysis Activity under Simulated Gastric Conditions

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• 作者：Junqi Zhao ; Pengjun Shi ; Huiying Luo ; Peilong Yang ; Heng Zhao ; Yingguo Bai ; Huoqing Huang ; Hui Wang ; Bin Yao
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2010
• 出版时间：March 10, 2010
• 年：2010
• 卷：58
• 期：5
• 页码：3184-3190
• 全文大小：811K
• 年卷期：v.58,no.5(March 10, 2010)
• ISSN：1520-5118

文摘

A β-mannanase gene, man5AP13, was cloned from Phialophora sp. P13 and expressed in Pichia pastoris. The deduced amino acid sequence of the mature enzyme, MAN5AP13, had highest identity (53%) with the glycoside hydrolase family 5 β-mannanase from Bispora sp. MEY-1. The purified recombinant β-mannanase was acidophilic and acid stable, exhibiting maximal activity at pH 1.5 and retaining >60% of the initial activity over the pH range 1.5−7.0. The optimum temperature was 60 °C. The specific activity, K_m and V_max for locust bean gum substrate were 851 U/mg, 2.5 mg/mL, and 1667.7 U/min·mg, respectively. The enzyme had excellent activity and stability under simulated gastric conditions, and the released reducing sugar of locust bean gum was significantly enhanced by one-fold in simulated gastric fluid containing pepsin in contrast to that without pepsin. All these properties make MAN5AP13 a potential additive for use in the food and feed industries.