摘要
以产生淀粉酶菌株Aspergillus niger AF-0为出发菌株,先后经紫外(UV)、亚硝基胍(NTG)诱变,选育得到了一株产酶活性较高的突变株,其所产马铃薯生淀粉酶的酶活力达43.8 U/mL,比原初酶活力19.3 U/mL提高了1.3倍。在此基础上,对该酶的部分酶学性质进行了研究。结果表明,该酶的最适反应温度为55℃,在60℃以下稳定;最适反应pH为4.0,在pH3.5～5.0范围内稳定;Mn2+,Fe2+,Zn2+,Mg2+,Ca2+,Ba2+对该酶有一定的激活作用,而Cu2+,K+,Na+则抑制酶的活性;该酶以形成孔洞的方式由外向内作用于马铃薯淀粉颗粒。
The raw-starch-hydrolysing amylase-producing strain Aspergillus niger AF-0 was used as original strain which was induced by UV and NTG for increasing the ability of enzyme production. One mutant with high yield of raw-starch-hydrolysing amylase was selected. The enzyme activity of this mutant increased from 19.3 U/mL to 43.8 U/mL, increased by 1.3 times. The enzyme produced by the mutant exhibited the maximun activity at pH 4.0 and 55 ℃. Furthermore, the enzyme performed stable over thepH range of 3.5 -5.0 and at 60 ℃. Mn^2＋ Fe^2＋, Zn^2＋, Mg^2＋ , Ca^2＋ and Ba^2＋ showed an obvious activation to the enzyme, while Cu^2＋ , K^＋ and Na^＋ inhibited its activity. The enzyme showed centripetal hydrolysis on potato starch with deep holes into the granules.
出处
《食品与机械》
CSCD
北大核心
2009年第2期11-14,33,共5页
Food and Machinery
基金
国家科技支撑项目(编号:2007BAD41B03)
关键词
生淀粉酶
诱变
酶学性质
Raw-starch-hydrolysing amylase
Mutation
Enzyme property
