植物乳杆菌ST-Ⅲ的β-果糖苷酶在大肠杆菌中的表达及优化  

Expression and optimization of a β-fructofuranosidase from Lactobacillus plantarum ST-Ⅲ in Escherichia coli

作　　者：陈臣[1,2] 周方方[2] 任婧[2] 刘振民[2] 陈卫[1] 

机构地区：[1]江南大学食品学院,江苏无锡214122 [2]乳业生物技术国家重点实验室,光明乳业股份有限公司研究院,上海200436

出　　处：《食品工业科技》2014年第11期155-159,共5页Science and Technology of Food Industry

基　　金：科技部“十二五”国家科技支撑计划课题(2013BAD18B01);科技部“十二五”国家863课题(2011AA100901)

摘　　要：为了了解植物乳杆菌利用低聚果糖的机理,以一株具有良好的利用低聚果糖能力的植物乳杆菌ST-Ⅲ基因组为模板,成功地扩增出β-果糖苷酶基因(sacA),基因片段长度为1506bp,编码501个氨基酸。将扩增出的目的片段克隆到pet28(a)(+)载体上,在大肠杆菌中进行表达,并优化了表达条件。IPTG浓度0.1mmol/L,诱导温度为16℃,诱导12h是该酶的最佳表达条件,比酶活为3.4U/mg;亲和层析纯化后,比酶活达到107.0U/mg。To establish the molecular mechanisms of fructooligosaccharides are metabolized by Lactobacillus p/antarum species, a β- fructofuranosidase gene （ designated sacA） from a fructooligosaccharides- fermenting strain Lactobacillus plantarum ST-Ⅲ was cloned into Escherichia coil, and the over-expression conditions of the recombinant protein were optimized.The sacA gene from L.plantarum ST-Ⅲ consisted of 1506 nucleotides, encoding a 501 amino acid polypeptide.The specific activity of enzyme was 3.4U/mg when induced with 0.1 mmol/ L IPTG for 12h at 16℃.The enzyme was then purified with nickel ion affinity chromatography and the specific activity was tOT.OU/mg for the purified recombinant protein.

关 键 词：植物乳杆菌 β-果糖苷酶 低聚果糖 

分 类 号：Q786[生物学—分子生物学]