拟康宁木霉聚半乳糖醛酸酶的酶学特征及潜在应用  

Enzymatic Characterization and Potential Application of Polygalacturonase from Trichoderma koningiopsis

作　　者：杨成玮 朱婧 韦云伊 杨媚 许文婷 程忠 YANG Chengwei;ZHU Jing;WEI Yunyi;YANG Mei;XU Wenting;CHENG Zhong(State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources,College of Life Science and Technology,Guangxi University,Nanning 530004,China;College of Food and Quality Engineering,Nanning University,Nanning 530200,China)

机构地区：[1]广西大学生命科学与技术学院,亚热带农业生物资源保护与利用国家重点实验室,广西南宁530004 [2]南宁学院食品与质量工程学院,广西南宁530200

出　　处：《食品科学》2023年第10期215-223,共9页Food Science

基　　金：广西高校中青年教师科研基础能力提升项目(2019KY0924);南宁学院科研项目(2018XJ42);南宁学院博士科研基金项目(2021DSRF01)。

摘　　要：从桂北果园土壤中筛选到1株产聚半乳糖醛酸酶(酶活力为29.2 U/mL)的丝状真菌,鉴定该菌为拟康宁木霉(Trichoderma koningiopsis)。以聚半乳糖醛酸为底物,测得该酶最适反应温度为50℃,且在50℃条件下保温1 h,仍能保持70%以上最大酶活力,属于中高温酶。该酶具有独特的弱酸性催化特征,最适反应pH 5.0,且在pH 6.0仍具有73%最大酶活力,并在pH 2.5~8.0条件下具有一定耐受性。Zn^(2+)对酶活性具有部分激活作用,Mn^(2+)则对该酶有一定抑制作用。针对5种弱酸性水果果浆(木瓜、香蕉、芭蕉及火龙果(红心和白心))脱胶实验结果显示,该酶对5种水果的脱胶效果都有不同程度提高,其中芭蕉果浆出汁率提高了24.4%,木瓜果浆黏度下降了82.5%,红心火龙果果浆透光率提高了31.9%,3种水果脱胶效果显著。本研究挖掘出一种新型产聚半乳糖醛酸酶菌株,对于热带、亚热带易腐烂水果的果汁生产具有较好的应用前景。A filamentous fungus producing polygalacturonase(29.2 U/mL)was isolated from orchard soil in northern Guangxi,and identified as Trichoderma koningiopsis.Using polygalacturonic acid as the substrate,the optimum reaction temperature of the enzyme was 50℃,and it maintained more than 70% of the maximum activity at 50℃ for 1 h,which was identified as a medium-high temperature tolerant enzyme.The enzyme had unique weakly acidic catalytic characteristics.The optimum reaction pH was 5.0,and it retained 73% of its maximum activity at pH 6.0,and was tolerant to pH 2.5-8.0.Zn^(2+)partially activated the enzyme activity,while Mn^(2+)inhibited the enzyme.It could depectinize five weakly acid fruit pulps(papaya,banana,banana,and white-and red-fleshed pitaya)but to different extents.The yield of juice of banana pulp increased by 24.4%,the viscosity of papaya pulp decreased by 82.5%,and the transmittance of red-fleshed pitaya pulp increased by 31.9%,indicating good depectinization efficiency for the three fruits.The polygalacturonase-producing strain has good prospects for its application in juice production from tropical and subtropical perishable fruits.

关 键 词：聚半乳糖醛酸酶 拟康宁木霉 鉴定 酶学性质 果浆脱胶 

分 类 号：TS261.1[轻工技术与工程—发酵工程]