细菌酶制剂对烟叶中蛋白质的降解作用研究  

Using Bacterial Enzyme to Degrade Protein in Tobacco(Nicotiana tabacum) Leaves

作　　者：王继莲[1] 李明源[1] 马永凯 王毅 魏云林[2] 

机构地区：[1]喀什师范学院生物与地理科学系,叶尔羌绿洲生态与生物资源自治区重点实验室,喀什844000 [2]昆明理工大学生物工程与技术研究中心,昆明650224 [3]红塔烟草集团有限责任公司,玉溪653100

出　　处：《农业生物技术学报》2014年第4期486-494,共9页Journal of Agricultural Biotechnology

基　　金：云南省中烟工业公司项目(No.2008YL06)

摘　　要：如何有效利用外源酶降解烟叶中的残留蛋白质,进一步提升烟叶质量成为烟草行业研究的新课题。本研究通过对玉溪烤烟叶面的细菌菌株的筛选鉴定,得到一株高产蛋白酶菌株,对其发酵培养制备成酶制剂,测定酶制剂活力并进行酶制剂性质研究。通过正交试验设计考察该酶制剂在不同施酶量(40、80和120 U/g烟叶)、温度(25、35和45℃)、相对湿度(50%、60%、70%)和作用时间(30、60和90 h)条件下对烟草(Nicotiana tabacum)K326中蛋白质的降解作用,并进一步分析了最优条件处理下烟叶香气成分的含量变化。结果表明,分离自烤烟烟叶表面的高产蛋白酶活菌株为短小芽胞杆菌(Bacillus pumilus)B1,所产蛋白酶活力为4 200 U/mL,最适温度50℃,最适pH 6.0。正交试验表明,其降解烟草蛋白的最适水平为加酶量120 U/g、温度35℃、相对湿度70%、作用时间60 h,蛋白质降解率为18.64%,氨基酸增加率为12.72%,同时烟叶中各香气成分也有不同程度增加。研究结果提示,以玉溪烟叶表面的细菌菌株为材料制得的细菌酶制剂处理醇化烟叶,可有效降解烟草中的大分子蛋白,缩短烟叶醇化时间,同时烟叶品质得到提升,该酶制剂可望在工业生产中应用。How to use exogenous enzyme effectively to degradate the protein in tobacco leaf,improving tobacco quality is a new research task in tobacco industry. A protease high-yielding strain was isolated from the surface of Yuxi tobacco（Nicotiana tabacum） leaves.The strain was cultivated and the protease was concentrated from the strain fermentation metabolites, protease activities and characterization of the enzyme were introduced in this paper. Orthogonal test was designed to detect the effection of enzyme quantity（40, 80 and 120 U/g）,temperature （25, 35 and 45 ℃）, relative humidity（50%、60% and 70%）） and reaction time（30, 60 and 90 h） to tabacco protein, aroma component was also analzsed under optimal conditions. Results illustrated that the activity of Bacillus pumilus strain B1 was 4 200 U/mL, the highest activity was under the conditions of pH 6.0 and 50 ℃. The optimal conditions for the enzyme was enzyme quantity120 U/g, temperature 35 ℃, relative humidity 70%, reaction time 60 h, the degradability rate of protein was 18.64% and the amino acid increased 12.72%, GC/MS showed that the amount of volatile aroma content increased significantly. The results suggested that the enzyme produced by the strain B1 isolated from the surface of Yu Xi tobacco leaves can degrade protein in flue-cured tobacco leaves, increasing the availability of lower - grade variety of tabacco, improving the qudlity of tabacco leave. And The enzymes can be applied in industrial production.

关 键 词：烤烟 GC MS 蛋白酶 

分 类 号：S852.2[农业科学—基础兽医学]