Bacillus subtilis γ-DES36纤溶酶发酵条件的优化研究

Optimization of fermentation conditions for fibrinolysin from B. subtilis γ-DES36

摘要: 以高活性纤溶酶突变株Bacillus subtilis γ-DES36为发酵菌株，研究其纤溶酶液体发酵的最佳工艺条件。通过对不同接种量、碳源、氮源、碳氮比、表面活性剂、金属离子等单因素研究，使用麦芽糖和胰胨时纤溶酶活性达2900 IU/mL左右。为了降低成本，使用廉价的碳氮源麸皮和豆粕粉。正交试验得到该菌株产纤溶酶的优化液体发酵条件为：麸皮1%，麦芽糖1%，胰胨0.25%，豆粕粉1.5%，吐温40 0.15%，酵母膏0.1%，K₂HPO₄ 0.25%，KH₂PO₄ 0.1%，复合无机盐0.2 mL/(100 mL)，接种量1%，发酵液纤溶酶酶活达到2300 IU/mL。

Abstract: The optimum fermentation conditions for the fibrinolysin from Bacillus subtilis γ-DES36 were investigated, and a mutant producing high-yield fibrinolysin was studied. The effects of inoculating amount, carbon source, nitrogen source, C/N ratio, surface activity agents and metal salts on the fibrinolysin production of mutant γ-DES36 were investigated, the fibrinolysin activity reached nearly 2900 IU/mL after adding maltose and tryptone. The best fermentation media were found to be: 1% maltose, 1% wheat bran, 0.5% tryptone, 1.5% soybean grit powder, 0.15% tween 40, 0.1% yeast extract, 0.25% K₂HPO₄,0.1% KH₂PO₄, 0.2 mL/(100 mL) mixture inorganic salts, and the proper inoculating amount 1%(v/v). The fibrinolysin activity of the fermented broth reached 2300 IU/mL.