基于酵母表面展示技术的耐热木聚糖酶全细胞催化剂的构建及酶学性质研究  

Construction of the thermostable xylanase whole-cell biocatalyst based on yeast cell surface display technology and enzymatic analyses

作　　者：邓香连 刘清怡 熊海容 张莉[1] DENG Xiang-lian;LIU Qing-yi;XIONG Hai-rong;ZHANG Li(College of Life Sciences,South-Central University for Nationalities,Wuhan 430074,China)

机构地区：[1]中南民族大学生命科学学院,武汉430074

出　　处：《湖北农业科学》2021年第7期120-125,134,共7页Hubei Agricultural Sciences

基　　金：国家自然科学基金青年项目(31802096);中央高校基本科研业务费专项资金资助项目(CZD19002)。

摘　　要：木聚糖酶是一种重要的工业用酶,在饲料、造纸、纺织、食品等领域有巨大的应用潜力。使用毕赤酵母表面展示技术,以细胞壁蛋白Gcw61为锚定蛋白,将实验室前期筛选获得的耐热木聚糖酶(DSB)展示在毕赤酵母表面,摇瓶发酵获得的全细胞催化剂的酶活力最高达13510 U/g。然后对DSB的全细胞催化剂和游离酶的酶学性质进行比较分析,2种酶的最适反应温度均为65℃,最适反应pH均为6.5,但在70℃高温条件和pH 3.0的酸性条件下,DSB全细胞催化剂的稳定性均优于DSB游离酶。此外在高浓度NaCl、高浓度甲醇、多种金属离子(Na^(+)、Ca^(2+)、Ni^(2+))的环境条件下,DSB全细胞催化剂均能维持较高的酶活且稳定性优于DSB游离酶。Xylanase is an important industrial enzyme with great potential for applications in feed,paper,textiles,food and other fields.In this study,the xylanase DSB was displayed on the cell surface of pichia pastoris using the cell wall protein Gcw61 as an anchor protein.The highest activity of DSB whole-cell biocatalyst reached 13510 U/g by shake-flask fermentation.Then the enzymatic properties of DSB whole-cell biocatalyst and free enzyme were determined.The results showed that the optimum reaction temperature of both enzymes was 65℃and the optimum reaction pH was 6.5.But the thermal stability of DSB whole-cell biocatalyst was better than free xylanase under high temperature condition 70℃and acidic condition pH 3.0.In addition,the DSB whole-cell biocatalyst could maintain high enzyme activity and was more stable than free xylanase under high concentration of NaCl,methanol and various metal ions(Na^(+),Ca^(2+),Ni^(2+)).

关 键 词：耐热木聚糖酶 全细胞催化剂 毕赤酵母 酶学特性 

分 类 号：Q814.9[生物学—生物工程]