一株具有溶解血纤维蛋白活性的菌株 A1,经亚硝基胍和紫外线复合诱变获得一株纤溶活性较高的突变株 C2 2 ,其半成品酶比活力可达到 2 94 7.6 0 u·mg-1蛋白 ,产酶活力为未诱变菌株的 4 .2 3倍。本文对其产酶的最适条件进行了优化 ,结果表明产酶最适培养条件为 :培养基组成 2 .5%豆饼粉 ,0 .1%酵母提取物 ,0 .2 % Na Cl,0 .0 5% Mg SO4 · 7H2 O,0 .0 0 1% Fe SO4 · 7H2 O,用 0 .0 5mol· L-1,p H7.4的磷酸缓冲液配制 ;培养基起始 p H7.0～ 7.5,2 5℃旋转摇床培养 4 0 A strain with soluble fibrinolytic activity, A1, was mutagenized with nitrosoguanidine and UV to obtain a strain C2 2 with higher fibrinolytic activity. The specific activity of the semi-finished product was 2 94 7.6 0 u · mg -1 protein, producing enzyme activity was 4.2 times the non-mutagenized strains. In this paper, the optimal conditions for the enzyme production were optimized. The results showed that the optimal culture conditions for the enzyme production were as follows: the medium consisted of 2.5% soybean meal, 0.1% yeast extract and 0.2% NaCl, 0. 0 5% Mg SO 4 · 7H 2 O, 0.010% Fe SO 4 · 7H 2 O, formulated with 0,05 mol · L-1, p H7.4 phosphate buffer; medium initial p H7.0 ~ 7.5,2 5 ℃ rotary shaker training 4 0