产右旋糖酐酶Marinimicrobium sp.G1的筛选、酶性质及产物研究  

Screening,Enzymatic Properties and Hydrolysates of Marinimicrobium Sp.G1 Produced Dextranase

作　　者：胡杰 刘鑫 祖航天 包瑞璇 吕明生 王淑军 HU Jie;LIU Xin;ZU Hangtian;BAO Ruixuan;LYU Mingsheng;WANG Shujun(Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology,Jiangsu Ocean University,Co-Innovation Center of Jiangsu Marine Bio-Industry Technology,Lianyungang 222005,China)

机构地区：[1]江苏海洋大学海洋资源与环境重点实验室/海洋生物技术重点实验室,江苏省海洋生物产业技术协同创新中心,江苏连云港222005

出　　处：《食品科技》2021年第5期25-32,共8页Food Science and Technology

基　　金：“十三五”国家重点研发专项(2018YFC0311106);江苏省高等教育优势学科项目(PAPD);江苏省研究生创新项目SJCX(19-1011)。

摘　　要：从海洋样品中筛选产右旋糖酐酶新颖的菌株。采用透明圈法从近海海泥中筛选到一株产右旋糖酐酶的菌株G1,根据16S rDNA基因序列、形态学和生理生化指标,鉴定为Marinimicrobium sp.。该菌产酶的最适碳源和氮源分别为蔗糖和鱼粉蛋白胨,在初始pH7.5、发酵温度30℃条件下发酵48 h产酶量最高。右旋糖酐酶的相对分子质量约为70 ku,最适温度为40℃,最适pH值为5.5;在5 mmol/L浓度条件下,Co^(2+)、K^(+)、Mn^(2+)、Sr^(2+)、Ca^(2+)、Na^(+)等离子对该酶活性有显著促进作用。经高效液相色谱(HPLC)检测,15 min的酶解产物中异麦芽三糖和异麦芽六糖的含量分别为43.8%和36.5%。检测了酶解产物的抗氧化活性,清除羟自由基的IC_(50)为2 mg/mL,清除超氧阴离子IC_(50)为10 mg/mL。该酶在食品工业特别是益生元的生产中具有较好的应用潜力。The purpose of study is to screen novel strains produced dextranase from marine samples.Strain G1 was isolated from marine mud by transparent zone method.It was identified as Marinimicrobium sp.according to 16S rDNA,morphology,and physiological and biochemical indexes.The optimal carbon and nitrogen sources for the enzyme production were sucrose and fish meal peptone,respectively;The yield of dextranase was the highest when the fermentation conditions were initial pH 7.5,30 ℃ for 48 h.The relative molecular mass of dextranase is about 70 ku,and its optimal reaction temperature and pH were 40 ℃ and 5.5,respectively.Co^(2+),K^(+),Mn^(2+),Sr^(2+),Ca^(2+),Na^(+) could significantly promote the enzyme activity when their concentration was 5 mmol/L.The hydrolysates were detected by HPLC,and the content of maltotriose and maltohexaose were 43.8% and 36.5% respectively.Furthermore,the antioxidant activity of the hydrolysates was measured.The IC_(50) of scavenging rate of hydroxyl radical was 2 mg/mL;the IC_(50) of scavenging rate of superoxide anion was 10 mg/mL.The dextranase has potential application prospect in food industries,especially for producing prebiotics.

关 键 词：Marinimicrobium sp. 右旋糖酐酶 酶学性质 酶解产物 抗氧化活性 

分 类 号：TS201.3[轻工技术与工程—食品科学]