解淀粉芽孢杆菌产纤溶酶的19L发酵罐实验及其酶学性质  

Production and Characterization of Fibrinolytic Enzyme from Bacillus amyloliquefaciens in 19 L Fermenter and Investigation of Its Properties

作　　者：刘林[1] 谢和[1] 

机构地区：[1]贵州大学生命科学学院,贵州贵阳550025

出　　处：《食品科学》2014年第7期176-180,共5页Food Science

摘　　要：在摇瓶实验的基础上,对解淀粉芽孢杆菌(Bacillus amyloliquefaciens)GZJSI-12-7产纤溶酶最佳条件进行19 L发酵罐实验,结果表明:GZJSI-12-7在发酵罐中培养6 h时开始产纤溶酶,78 h后纤溶酶产量基本稳定,达到4 178.39 IU/mL,产酶高峰比摇瓶发酵提前12 h左右。将发酵液经离心除菌、硫酸铵分级盐析、透析除盐、Sephadex G-75凝胶过滤,得到纤溶酶的纯化倍数为9.84倍,酶活力回收率为42.52%,比活力为48 073.193 IU/mg。对纤溶酶的酶学性质研究表明,该酶的分子质量约为30.2 kD,最适温度和pH值分别为40℃、7.5;在40℃以下酶的稳定性良好,超过50℃后酶活力迅速降低,耐热性较差;金属离子Mg2+、Ca2+、Mn2+对纤溶酶活性均有较强的激活作用,而Cu2+和Fe3+对酶活性具有明显的抑制作用。As an extension of our previous fermentation experiments in shake flasks,the objective of this study was to optimize the fermentation conditions for the production of fibrinolytic enzyme by Bacillus amyloliquefaciens GZJSI-12-7 in a 19 L fermenter.The results showed that plasmin activity began to appear after incubation for 6 h and remained constant after 78 h at a level of 4 178.39 IU/mL.The peak of enzyme production occurred about 12 h earlier than in shake flasks.Fibrinolytic enzyme was purified from the fermented liquid medium by bactofugation,ammonium sulfate precipitation,dialysis and Sephadex G-75 gel filtration,with a purification fold of 9.84 and an activity recovery of 42.52％.The specific activity of the purified fibrinolytic enzyme was 48 073.193 IU/mg.Enzymatic characterization showed that the molecular weight of the fibrinolytic enzyme was about 30.2 kD,and its optimum temperature and pH were 40 ℃ and 7.5,respectively.The purified fibrinolytic enzyme was stable blow 40 ℃ but sharply decreased above 50 ℃.The enzymatic activity was markedly catalyzed by Mg2＋,Ca2＋ and Mn2＋,but strongly inhibited by Cu2＋ and Fe3＋.

关 键 词：解淀粉芽孢杆菌 纤溶酶 发酵 分离纯化 酶学性质 

分 类 号：TQ464.8[化学工程—制药化工]