作　　者： ; ; ; ; ; ; ; ;

机构地区： 广西大学生命科学与技术学院

出　　处： 《应用与环境生物学报》 2013年第2期342-345,共4页

摘　　要： 为开发新型淀粉酶,鉴定了来自绿色糖单孢菌(Saccharomonospora viridis)在Genbank中注释为糖苷酶(Glycosidase)的一个ORF,研究表明该ORF编码一种α-淀粉酶.重组酶酶学性质的研究表明以可溶性淀粉为底物反应的最适pH为6.6,在pH 5.6-8.6有80%以上的相对活力,最适温度为60℃,比活力为319.49 U/mg.它与可溶性淀粉、六糖、五糖、四糖、三糖反应,经HPLC检测产物均为麦芽三糖、麦芽糖和葡萄糖的混合物.重组酶与20%的可溶性淀粉反应,产物含有高达67.15%的麦芽糖,还原糖的转化率约为75%,加入普鲁兰酶后,麦芽糖含量增加到69.7%,还原糖转化率约为91%,不能与麦芽糖、α-环糊精、β-环糊精和普鲁兰糖反应. An open reading frame （ORF） in Saccharomonospora viridis sequenced genome was identified to encode a α-amylase, annotated as “glycosidase” in the GenBank database. The recombinant enzyme showed its optimal activity was at 60 ℃ and pH 6.6 when it hydrolyzed soluble starch. It had 80% and higher relative activity at pH 6.6-8.6, and its specific activity was 319.49 U/mg. The results of HPLC showed that the hydrolysis products of soluble starch, maltohexaose, maltopentaose, maltotetraose and maltotriose using this α-amylase all contained glucose, maltose and maltotriose. And the hydrolysis products of soluble starch （20%） contained up to 67.15% of maltose, with the conversion rate of starch into reducing sugar about 75%. When pullulanase was added, the content of maltose increased up to 69.7% while the conversion rate of starch into reducing sugar increased to 91%. However, this protein could not hydrolyze maltose, α-cyclodextrin, β-cyclodextrin or pullulan. The result therefore suggested that this amylase could be applied to manufacture high maltose syrup. Fig 4, Tab 1, Ref 13

关 键 词： 绿色糖单孢菌 淀粉酶 克隆表达 麦芽糖 酶学性质

领　　域： [轻工技术与工程] [化学工程] [生物学]