红曲霉产生淀粉酶固态发酵条件的优化及部分酶学性质

Optimization of raw-starch-hydrolysing amylase production by Monascus in solid state fermentation and partial enzymological properties

以红曲霉M2为研究对象，在单因素试验的基础上，确定无机盐水添加量、培养时间、培养温度和培养基初始pH四个因素的取值范围，以生淀粉酶活力为指标设计正交试验优化了培养条件，并对最优条件下生淀粉酶的部分酶学性质进行了研究。结果表明：温度为32℃，pH值5．0，无机盐水量为14mL，培养时间6d时酶活最高可达445．37u／g；该酶的最适反应温度为40℃，最适反应pH为5．0，在pH值为5．0～7．0范围内较稳定，热稳定性较差，在60℃保温2h残余酶活只有23．9％；Zn^2＋，Mn^2＋，Cu^2＋对该酶有促进作用，Ba^2＋和Fe^3＋对该酶有抑制作用，Na^＋，K^＋，Mg^2＋对该酶基本无影响。

With monascus M2 as the research object, on the basis of single factor experiment, ranges of the four factors including inorganic salt water adding amount, incubation time, incubation temperature and medium initial pH value were determined. In addition, orthogonal experiment was designed with raw-starch-digesting amylase activity as an index to optimize the culture condition, and some properties of amylase under the optimal conditions were studied. Results showed that the , , enzyme activity reached 445.37 u/g in 14mL inorganic salt water incubated at 32℃ and pH 5.0 for 6d. Optimum reaction temperature for the enzyme was 40℃. The optimum pH was 5.0, and the enzyme was relatively stable at pH 5.0 - 7.0. The residual enzyme activity was only 23.9% after incubation at 60℃ for 2h because of its low thermal stability. Zn^2＋ , Mn^2 ＋ , Cu^2＋ could promote the activity of the enzyme, Ba^2 ＋ and Fe^3 ＋ could inhibit its activity, and Na^＋ , K ^＋ ,Mg^2＋ have no effect on it.