一株产右旋糖苷酶海洋细菌的筛选鉴定  

Screening, identification and characterization of a dextranase-producing marine strain

作　　者：李卫娟[1,2] 焦豫良[2] 吕明生[2] 房耀维[2] 李华钟[1] 李秋潼[3] 王淑军[2] 

机构地区：[1]江南大学工业生物技术教育部重点实验室,江苏无锡214122 [2]淮海工学院海洋学院,江苏连云港222005 [3]常州大学石油化工学院,江苏常州213164

出　　处：《微生物学通报》2013年第5期756-765,共10页Microbiology China

基　　金：国家863计划项目(No.2011AA09070302);连云港市自然科学基金项目(No.CG1003);江苏高校优势学科建设工程资助项目

摘　　要：【目的】筛选鉴定产右旋糖苷酶的海洋细菌,并对其所产右旋糖苷酶的酶学性质及在变异链球菌牙菌斑生物膜中的应用进行初步研究。【方法】利用平板透明圈法从海洋环境中筛选产右旋糖苷酶的细菌,根据菌株形态特征、生理特征及16S rDNA序列确定其分类学地位,采用体外生物膜模型研究该酶对变异链球菌牙菌斑生物膜形成的抑制作用。【结果】从海泥中筛选出一株产右旋糖苷酶的细菌KQ11,初步鉴定为节杆菌(Arthrobacter sp.)。该菌株的最适生长温度为30°C,最适生长pH 7.5,最适生长NaCl浓度为0.4%。右旋糖苷酶的最适作用温度为45°C,最适作用pH为5.5。该酶能有效地抑制变异链球菌牙菌斑生物膜的形成。【结论】菌株KQ11右旋糖苷酶能够抑制变异链球菌牙菌斑生物膜的形成,可望用于漱口液等口腔护理产品中。[Objective] This study is aimed to isolate and identify a strain which can produce dextranase, characterize the enzyme properties and study its application in Streptococcus mutans dental biofilm. [Methods] The strains derived from marine environment were screened by observing transparent circle on agar plates. The strains were identified by morphology, physiological characteristics, and phylogenetic analysis based on 16S rDNA sequences. The inhibitory effect of the dextranase on Streptococcus mutans dental biofilm was assessed with biofilm models in vitro. [Results] A dextranase-producing strain KQ11 was isolated from sea mud and preliminarily identified as Arthrobacter sp.. The optimal growth conditions of the strain were 30 °C, pH 7.5, and NaCl concentration of 0.4%. The optimal catalytic conditions of the enzyme were 45 °C, pH 5.5. The dextranase effectively prevented the dental biofilm formation by Streptococcus mutans. [Conclusion] The dextranase from the strain KQ11 can effectively degrade Streptococcus mutans dental biofilm, and thus it can be added to the oral care products such as mouthwash.

关 键 词：ARTHROBACTER SP 右旋糖苷酶 筛选 鉴定 

分 类 号：TQ925[轻工技术与工程—发酵工程]