一株青藏高原冻土溶栓菌的筛选及鉴定

【目的】心脑血管疾病是一种世界性疾病,严重危害人类健康,溶栓酶是治疗该病的有效药物之一。而极端环境中的溶栓微生物因其特殊的生存方式,可能分泌高效、安全的新型溶栓酶。因此,为了获得这种具有特殊功能的溶栓酶,我们从青藏高原高海拔冻土中进行了溶栓菌的筛选。【方法】首先,本文通过血粉-琼脂平板初步筛选具有血粉水解功能的菌株,然后对其进行体外溶栓试验以检验其人工血栓溶解功能,并用纤维蛋白平板法测定其纤溶活性,最后通过生理生化试验和16S rRNA基因序列分析方法对该菌进行分类鉴定。【结果】本文从青海省玉树藏族自治州海拔4300 m的冻土样品中筛选获得了菌株DR-536,不仅具有水解血粉的功能,还具有体外溶栓功能,且能够水解纤维蛋白,纤溶活性为51.80 IU/mL(以尿激酶为标准)。最后,分类鉴定结果显示菌株DR-536是一株金黄节杆菌(Arthrobacter aurescens)。【结论】本文首次从青藏高原高海拔土壤中进行了溶栓菌的筛选,并获得了一株新型溶栓菌,为进一步研究和开发高效、安全的新型溶栓酶提供了菌源。

Isolation and identification of a fibrinolytic bacterium strain from frozen soil in the Tibetan Plateau

Abstract: Objective] Cardiovascular disease, harmful to human health, is a worldwide disease, for which fibrinolytic enzyme is usually used as an effective remedy. Fibrinolytic microbes under extreme environmental conditions may excrete some high efficient and safe fibrinolytic enzymes. So, for obtaining this fibrinolytic enzyme, we isolated fibrinolytic strains from frozen soil in the Tibetan Plateau. Methods] We screened microbes hydrolyzing blood powder by blood powder (bovine)-agar plate, followed by detection of thrombolysis effect through thrombolytic test in vitro. After that, we detected and measured the fibrinolytic activity of those microbes screened above with fibrin plates. Finally, we classified and identified the fibrinolytic microbes by combining physiological and biochemical test and 16S rRNA gene sequence analysis. Results] We isolated a strain DR-536 from frozen soil at 4300 m altitude in Yushu Tibetan Autonomous Prefecture, Qinghai Province. We found that the strain DR-536 not only hydrolyzed blood powder in the blood-agar plate, but also completely dissolved thrombus in vitro. We also found that strain DR-536 could hydrolyze fibrin, and the fibrinolytic activity was 51.80 IU/ml (with Urokinase as a standard). At last, results of classification and identification indicated that DR-536 is a new strain of Arthrobacter aurescens with fibrinolytic function. Conclusion] We provided a strain for research and exploitation of novel fibrinolytic enzymes.