摘要
从白酒大曲中分离纯化米曲霉菌种,对其进行发酵培养;再对米曲霉的发酵干曲中性蛋白酶进行分离,并对其酶学性质进行研究.结果表明:米曲霉中性蛋白酶的最佳提取方法为加入生理盐水,置于恒温(30℃)下,提取30 min.硫酸铵沉淀中性蛋白酶的最适浓度为80%.该中性蛋白酶的最适作用温度为55℃,最适pH值为7.0,该酶在40℃下的稳定性较好,该中性蛋白酶pH稳定范围为6.0～8.0;NaCl和EDTA对中性蛋白酶活力具有抑制作用.
Aspergillus oryzae was produced from yeast of liquor by inclined plate separation.A neutral protease was separated from A.oryzae and its characteristics were also studied.The results showed that the suitable extraction conditions of neutral protease were at 30℃,with saline,for 30 minutes.The extraction was stirred per 10 min,finally filtered with 4 layers of gauze.The optimal concentration of ammonium sulphate for enzyme precipitation was 80%.The optimum temperature and pH for neutral protease catalysis were 55℃ and 7.0.The enzyme remained stable at 40℃,when treated at 50℃ for 80 minutes and 60℃ for 20 minutes,the activity of crude enzyme could not be detected.The stable range of pH for neutral protease was 6.0~8.0.NaCl and EDTA had inhibitory effect on the enzyme.
出处
《河南科技学院学报（自然科学版）》
2011年第2期43-48,共6页
Journal of Henan Institute of Science and Technology(Natural Science Edition)
关键词
米曲霉
中性蛋白酶
酶学性质
Aspergillus oryzae
neutral protease
enzyme properties
