三七渣固态发酵所产淀粉酶的酶学特性研究

Enzymatic Characteristics of Amylase from Notoginseng Residues by Solid State Fermentation

考察了黑曲霉固态发酵三七渣所产淀粉酶的酶学特性.研究结果表明,该淀粉酶的最适温度为60℃;当温度为30～50℃时,具有较好的热稳定性,保温处理2h后其酶活仍可保持在90％以上;其最适pH为5.0;当pH为3.0～5.0时,具有较好的pH稳定性,在4℃冷藏保存2h后其酶活仍可保持在80％以上;Mn2＋对该淀粉酶有轻微的激活作用,K＋、Na＋、Mg2＋、Fe3＋、Zn2＋和Ni2＋对该淀粉酶有弱抑制作用,Cu2＋则对其有强抑制作用.该淀粉酶米氏常数Km值为0.64 mg·mL-1,最大反应速率Vmax为0.45 mg/min.

Enzymatic characteristics of the amylase produced from notoginseng residues by Aspergillus niger in solid state fermentation have been investigated in the paper. The results showed that the amylase had optimal activity at 50 ℃ and was stable in the range of temperature from 30 to 50 ℃. Over 90% of enzyme activity still remained even after incubation at 30 to 50℃ for 2 h. In addition, it operated most efficiently at pH 5.0 and possessed considerable pH stability, with 80% enzyme activity retained at pH 3.0 to 5.0 after 2 h at 4℃. It was also observed that the amylase was activated slightly by Mn2~ while inhibited weakly by K＋ , Na＋ , Mg2＋, Fe3＋, Zn2＋ , Ni2＋ , while strongly inhibited by Cu2＋. The amylase showed Km and Vmax values of 0.64 mg/mL and 0.45 mg/min, respectively.