豆渣固体发酵产纳豆激酶的工艺优化及其部分酶学性质研究

STUDY ON THE TECHNOLOGIES AND SOME ENXYME PROPERTY OF NATTO-KINASE PRODUCED FRCM THE SOLID FERMENTATION OF SOYBEAN RESIDUE

研究纳豆菌固体发酵产纳豆激酶的工艺及其部分酶学性质。采用单因素和正交试验,对以豆渣为原料纳豆菌固体发酵生产纳豆激酶的工艺条件进行优化,并利用最佳发酵工艺制备纳豆激酶粗品,对纳豆激酶的部分性质进行研究。结果表明固体发酵培养基最佳配比:豆渣:麸皮=5:2,初始含水量65%,接种量为 10%,初始 pH为 8.0,培养温度 30℃。采用最适培养基和优化工艺,在250 ml三角瓶中进行验证实验,纳豆激酶的酶的产率可达到 1577U·.g- 1。酶学性质研究表明,最适反应温度为60℃,37℃以下稳定,最适反应pH为8.0,在 pH7-9 溶液中基本稳定。体外溶栓作用表明,纳豆激酶溶解纤维蛋白的方式是直接溶解,而不是通过激活纤溶酶原。

Study on the technologies and some enzyme property of Natto-kinase produced from the solid fermentation of soybean residue was conducted. With single-factor and orthogonal test. The results showed that the optimal medium of solid fermentation was as follows soybean was residue:wheat bran was 5∶2;initial moisture content was 65%;the inoculum size was 10%;initial pH 8.0, and temperature was 30℃.Natto-kinase activity was 1577 U·g-1 when the strain was grown on the optimal medium under the above culture conditions in 250 mL Erlenmeyer fiask. The optimum temperature and pH for hydrolysis of casein were 60℃ and 8.0 respectively.The enzyme was stable up to 37℃,within the pH range of 7-9.The fibrinolysis activity was performed by degrading the fibrous protein directly according to the experiment in vitro.