一株产耐酸性α-淀粉酶菌株的鉴定及其酶学性质研究  

Identification of an Acid-stable α-Amylase-Producing Strain and Its Enzymatic Characteristics

作　　者：杨艳红[1] 李世川[1] 兰世玉 朱巍[1] 

机构地区：[1]重庆理工大学药学与生物工程学院生物工程系,重庆400054

出　　处：《天然产物研究与开发》2015年第9期1544-1549,共6页Natural Product Research and Development

基　　金：重庆市自然科学基金(cstc2014jcyj A0211)

摘　　要：随着现代淀粉工业的发展,寻找耐酸性新型α-淀粉酶成为研究热点。实验室分离到一株高产耐酸性α-淀粉酶菌株AF1。通过形态学观察法、生理生化特征与16Sr DNA序列分析鉴定出AF1菌株为解淀粉芽孢杆菌（Bacillus amyloliquefaciens）。对其酶学性质进行初步研究发现,该酶最适作用温度为75℃,p H为5.0;在温度60℃以下,p H 5.0~7.0范围内酶活比较稳定;Cu2＋对酶活有明显抑制作用,K＋、Li＋、Fe3＋则对酶活有轻微抑制作用,Na＋、Ca2＋、Ba2＋、Mg2＋和EDTA则对酶活没有明显影响。可见,本研究中的α-淀粉酶是一种不依赖于Ca2＋的耐酸性α-淀粉酶,在淀粉加工过程中,不仅不用加Ca2＋以维持酶的活性,同时可以不用p H调节,实现在弱酸性条件下淀粉液化和糖化同步进行,从而精简工序,节约成本。With the development of modem starch industry,looking for new acid-stable α-amylase become a research hot spot. AF1 producing acid-stable α-amylase with high enzyme activity was isolated from the PDA medium. It was identi- fied as Bacillus amyloliquefaciens based on morphological characteristics, physiological and biochemical characteristics and 16S rDNA gene sequence. Its enzymatic properties showed that the optimal reaction temperature was 75 ~G ,the pH was 5.0. Its enzyme activity remained at more than 80% in pH 5.0-7.0 for I h. It was stable under the temperature of 60℃. But its activity decreased significantly up to 70℃ ,even decreased to zero at 80 ℃for only 30 rain. Also,this or- amylase was inhibited obviously by Cu2＋ but not affected by Na＋ ,Ca2＋ ,Ba2＋ ,Mg2＋ and EDTA. It was indicated that the a-amylase from AF1 was an acid-stable a-amylase with Ca2 ＋ independent. This a-amylase can be used together with glueoamylase avoiding pH adjustment and no Ca2 ＋ added into the reaction system to keep the stability of the a-amylase during the starch processing. Hence,the process was simpler and the cost was lower when the liquefaction and saceharifi- cation process at the same time under low acid condition with this a-amylase.

关 键 词：解淀粉芽孢杆菌 菌株鉴定 酸性Α-淀粉酶 酶学性质 

分 类 号：Q939.9[生物学—微生物学]