产纤溶酶菌株L21的鉴定与发酵条件研究

Identification of fibrinolytic enzyme-producing strain L21 and its fermentation conditions

利用纤维蛋白平板法从海参体内肠道中筛选到一株产纤溶酶活力较高的菌株L21,通过16S r DNA序列测定比对分析,初步鉴定菌株L21为交替假单胞菌(Pseudoalteromonas sp.)。采用单因素试验、Plackett-Burman试验及响应面法对菌株L21的发酵条件进行优化,结果表明,菌株L21最佳发酵工艺条件为NaCl 1 g/L,CaCl_21.03 g/L,MgSO_40.8 g/L,初始p H 7.40。在此工艺条件下,菌株L21纤溶酶活力达到399.86 U/m L,较优化前(86.09 U/m L)提高了4.64倍。体外溶血实验结果表明该菌株具有作为安全性溶栓剂的潜力。

A high activity fibrinolytic enzyme-producing strain L21 was isolated from the intestinal tract of sea cucumbers by fibrinogen plate method. Strain L21 was identified as Pseudoalteromonas sp. by 16S rDNA sequence determination and analysis. The single factor experiments, Plackett-Burman experiments and response surface methodology were applied to optimize the fermentation conditions of strain L21. The results showed that the optimum fermentation process conditions of strain L21 were NaCl 1 g/L, CaCl2 1.03 g/L, MgSO4 0.8 g/L and initial pH 7.40. Under the conditions, the fibrinolytic enzyme activity of strain L21 was up to 399.86 U/ml, which was 4.64 times higher than that of before optimization （86.09 U/mL）. The results of in vitro hemolysis experiments indicated that strain L21 had potential as a safe-soluble suppository.