绿色糖单孢菌高产麦芽糖α-淀粉酶基因的克隆表达及酶学性质  

Gene Cloning, Expression and Enzymatic Characterization of a High Maltose-producing α-amylase from Saccharomonospora viridis

作　　者：汪小波[1,2] 李美蓉[1,2] 李雪[1,2] 黄坚丽[1,2] 黄英[1,2] 杜丽琴[1,2] 黄日波[1,2,3] 韦宇拓[1,2] 

机构地区：[1]广西大学生命科学与技术学院,南宁530005 [2]亚热带农业生物资源保护与利用国家重点实验室,南宁530005 [3]国家非粮生物质能源研究工程中心,南宁530007

出　　处：《应用与环境生物学报》2013年第2期342-345,共4页Chinese Journal of Applied and Environmental Biology

基　　金：广西科学研究与技术开发计划(11107008-3)资助~~

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 Α-淀粉酶 克隆表达 麦芽糖 酶学性质 

分 类 号：TQ925[轻工技术与工程—发酵工程]