低温β-1,4-内切葡聚糖酶的基因挖掘、异源表达及其酶学性质表征  

Gene mining,heterologous expression and characterization of enzymatic properties of low-temperatureβ-1,4-endoglucanase

作　　者：圣弟青 钮成拓 闫亚楠 郑飞云[1] 刘春凤[1] 王金晶 李崎[1] SHENG Diqing;NIU Chengtuo;YAN Yanan;ZHENG Feiyun;LIU Chunfeng;WANG Jinjing;LI Qi(Key Laboratory of Industrial Biotechnology,Ministry of Education,Jiangnan University,Wuxi 214122,China)

机构地区：[1]工业生物技术教育部重点实验室(江南大学),江苏无锡214122

出　　处：《食品与发酵工业》2024年第4期17-24,共8页Food and Fermentation Industries

基　　金：国家重点研发计划子课题(2021YFC2100404)。

摘　　要：β-1,4-内切葡聚糖酶在洗涤行业有着广泛的应用价值,其中具有较好的低温和碱性耐受能力是其实现工业应用的重要前提。该论文通过基因挖掘获得一株具有低温耐受能力的Deinococcus cellulosilyticus来源新型β-1,4-内切葡聚糖酶基因EgDC,并将其在大肠杆菌中实现了可溶性表达,其中大部分存在于周质空间,少部分分泌至胞外。对EgDC酶的酶学性质进行了表征,发现该酶的最适温度和最适pH值分别为40℃和pH 6.5,其在20℃能保持70%以上活力,且在pH 8.0和pH 9.0的半衰期分别达到83.43 min和53.79 min。EgDC酶具有较好的催化性质,其比酶活力k_(cat)/K_(m)值分别为(26.38±1.43)U/mg和(520.03±17.07)s^(-1)/mg,且对于金属离子以及表面活性剂均具有较强耐受能力。由此可见,新型β-1,4-内切葡聚糖酶EgDC具有较好的催化能力,且在低温、碱性以及存在表面活性剂环境下较为稳定,因此具有潜在的工业应用价值。There is a wide range of applications forβ-1,4-endoglucanase in the detergent industry,which with good low temperature and alkaline tolerance is an important prerequisite for its industrial application.In this thesis,a novelβ-1,4-endoglucanase gene EgDC from Deinococcus cellulosilyticus with low-temperature tolerance was obtained by gene mining.It was expressed in Escherichia coli,with most of it existed in the periplasmic space and a small portion secreted to the extracellular space.The enzymatic properties of EgDC enzyme were characterized,and it was found that the optimum temperature and pH of the enzyme were 40°C and pH6.5,respectively.It could maintain more than 70%of its activity at 20°C,while its half-life reached 83.43 min and 53.79 min at pH8.0 and pH9.0.Theβ-1,4-endoglucanase EgDC had good catalytic properties with specific enzyme activity and k_(cat)/K_(m) values reaching(26.38±1.43)U/mg and(520.03±17.07)s^(-1)/mg,respectively,which is also highly tolerant to metal ions and surfactants.Thus,the newβ-1,4-endoglucanase EgDC has good catalytic ability and is stable at low temperature,alkaline environment and in the presence of surfactant.Therefore,it has potential industrial applications.

关 键 词：基因挖掘 β-1 4-内切葡聚糖酶 异源表达 酶学性质 低温 耐碱性 

分 类 号：Q789[生物学—分子生物学] TQ925[轻工技术与工程—发酵工程]