摘要
以泸型大曲中分离的黑曲霉为菌种,采用固态发酵来产酸性蛋白酶,以发酵产物中酸性蛋白酶酶活为指标,对菌种产酸性蛋白酶的发酵条件进行了优化,同时对所产酸性蛋白酶的酶学性质进行了研究,实验结果表明:当麸皮:豆粕=6:4、玉米粉2.0%(g/g)、NH4Cl浓度2.5%(g/g)、持水量95%(mL/g)、初始pH6.0,培养时间50h,培养温度28℃,接种量6.0%时,发酵产物酸性蛋白酶酶活达24350U/g,平均酶活比初始培养基提高64.6%。对菌株所产酸性蛋白酶酶学性质的研究得出:该酶最佳反应温度为55℃,最佳反应pH为3.5,温度50℃以下该酶较稳定,2mmoL/L的K+、Cu2+、Ca2+、Fe+、Ag+离子对该酶具有激活作用,而同浓度的Fe3+、Fe2+、Zn2+离子对该酶具有抑制作用。
Acid protease was obtained by solid fermentation of Aspergillus niger , The fermentation conditions and enzymatic properties of the acid proteases were studied,and fermentation conditions were optimized.It was showed that, when the proportion of wheat bran and soybean meal was 6：4, corn flour 1.0%（g/g）, NH4Cl 2.5%（g/g）, water holding capacity 95%（mL/g）,pH6.0, fermentation time is 50 hours, fermentation temperature is 28 ℃, and 6.0% inoculation. The activity of acid protease reached to 24350U/g , which was increased by 64.6% after optimized.The enzymatic properties was also studied.The enzyme acted optimally at 55℃ ,pH3.5 ,and was stable below 50℃.Cu^2＋,K^＋, Ca^2＋,Fe^2＋ increased the activity to some extent when concentration is 2mmoL / L,while the activity of acid protease was decreased after adding Fe^3＋,Fe^2＋, Zn^2＋, Ag^＋.
出处
《食品与发酵科技》
CAS
2011年第2期13-17,31,共6页
Food and Fermentation Science & Technology
基金
"川菜发展中心"项目"高效曲种的优化及其在酱油酿造中的应用研究"(CC08Z06)
肉类加工四川省重点实验室项目"屠宰废水生物处理嗜温菌的筛选及其应用研究"(10R08)
四川省应用基础项目"调味品生产中提质控耗关键技术研究"(2010JY0081)
关键词
黑曲霉
酸性蛋白酶
发酵条件优化
酶学性质
Aspergillus niger, acid protease, fermentation conditions optimized, enzymatic properties
