蛹虫草是著名的药用真菌，具有扩张气管、镇静、抗心律失常、降血压、抗病原微生物、抗恶性肿瘤等多种药理活性。本研究采用蛋白纤维平板法筛选出具有溶纤活性的蛹虫草菌株，通过综合分析，选择产纤溶酶比活性最高的菌株，并对该菌株的产酶条件进行了优化。研究结果显示：菌株产酶最佳营养条件的组分为2%葡萄糖，2%蛋白胨，碳氮比为1/1；最佳环境条件为温度25 ℃，pH为6，装液量60 mL，发酵周期9 d，接种量2%，转速150 r/min。在此条件下，发酵液纤溶酶活力可达到111.85 U/mL。

Cordyceps militaris was one of the most popular edible mushrooms. It is a nutritious food source and contains bioactive metabolites with several medicinal effects including anti-tumor, hypocholesterolemic, antioxidant and anti-diabetic activities. In this study, fibrin fibrinolytic enzyme-producing strains were screened from Cordyceps militaris by plate method and specific activity. The fermentation conditions of the fibrinolytic enzyme producing were investigated. The results showed that the best fermentation medium contained 2% glucose, 2% peptone and 1/1 the ratios of carbon to nitrogen. The optimum fermentation conditions were pH 6.0, the temperature 25 ℃, the rotation speed 150 r/min, the fermentation time 9 d, the inoculum size 2% and medium volume 60 mL. Under such conditions, the fibrinolytic enzyme activity was 111.85 U/mL.

国家自然科学基金项目（31071837，30371000），广东省科技计划项目（2010A020501001，2011B090400412，2012B020316004），广东省科技攻关重点项目（2012A020100010）