一株产纤溶酶菌株的分离、鉴定及其酶活特征的初步研究

Isolation and identification of a fibrinolytic bacterium

摘要:

【目的】分离筛选并鉴定产纤溶酶的菌株。【方法】采用血粉培养基富集, 琼脂糖-纤维蛋白平板筛选, 从自然界中分离筛选出一株产纤溶活性物质的菌株。通过形态学特征、生理生化特征研究, 并结合16S rRNA基因序列分析及分子系统发育树的构建结果, 确定菌株的种类。【结果】从自然界分离筛到一株产纤溶酶的菌株EF608, 经鉴定该菌株为粪肠球菌(Enterococcus faecalis)。SDS-PAGE和纤维蛋白自显影表明该纤溶酶的分子量为37 kD, 最适反应温度和pH分别为35 °C和7.5, EDTA能完全抑制其纤溶活性, 而PMSF对其活性无抑制作用。菌株EF608发酵液不仅可以直接水解纤维蛋白, 而且具有体外溶栓的作用, 对血红细胞没有溶解作用。【结论】筛选到一株具有纤溶活性的粪肠球菌——EF608, 为获取新型纤溶酶提供了一种的新的菌源。

Abstract:

[Objective] We isolated and identified strains producing fibrinolytic enzyme. [Methods] A strain with fibrinolytic activity was isolated from the environment by using blood powder plates and agar-fibrin plates. We identified the strain by morphological, physiological and biochemical characterization, combined with 16S rRNA gene sequence and phylogenetic tree. [Results] A strain (named EF608) with fibrinolytic activity was obtained and identified as Enterococcus faecalis. Fermentation broth of strain EF608 had fibrinolytic activity. Its optimal reactive temperature and pH value were 35 °C and 7.5, respectively, and the molecular weight is 37 kD by SDS-PAGE and fibrin autography. EDTA completely inhibited the fibrinolytic activity, but PMSF exerted little effect on it. The fermentation broth dissolved thrombus in vitro, directly degrade the fibrin, and did not hydrolyze blood cells. [Conclusion] The strain might provide a new source for novel fibrinolytic enzymes.