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

以高活性纤溶酶突变株B acillus subtilisγ-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%,K2HPO40.25%,KH2PO40.1%,复合无机盐0.2mL/(100 mL),接种量1%,发酵液纤溶酶酶活达到2300 IU/mL。

The optimum fermentation conditions for the fibrinolysin from Bacillus subtilis T-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 T-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.