产中性蛋白酶菌株B_4发酵条件的研究

Studies on protease producing characteristics of Bacillus B_4

对从土壤中分离纯化得到的一株芽孢杆菌B4进行了发酵条件的探索。通过单因素碳源、氮源以及正交试验确定了B4最佳培养基配方。实验结果表明 :不同的碳、氮源及其配比对产酶有极大的影响。最佳培养基配方为 :玉米粉 2 %、豆饼粉 3%、麸皮 3%、Na2 HPO4·12H2 O 0 .4 %、KH2 PO40 .0 3%、ZnCl2 0 .1%、pH8.0 ,在最佳培养条件下 ,酶活由 2 71.5 6U/ml提高到 2 5 19.35U/ml,提高了 8倍多。同时还研究了金属离子、起始pH值、接种量对产酶的影响。

The fermentation conditions of Bacillus B_4 was studied on various carbon resources, various nitrogen resources and orthogonal experiment. The results showed that the fermentation medium had remarkable effects on protease producing. The optimum fermentation medium containing 2% corn meal, 2% soy bean cake powder, 3% bran, 0.4%Na_2HPO_4·12H_2O, 0.03% KH_2PO_4, 0.1% ZnCl_2, pH 8.0. Under the optimum conditions, protease activity was improved from 271.56 U/ml to 2519.35 U/ml. The effects of metal ions, primary pH value and inoculum size on protease producing were studied.