嗜热链球菌中CRISPR序列的检测与同源性分析.pdf

※生嘞工程
品学
2013,Vol34,No.03151
嗜热链球菌中 CRSPR序列的检测与同源性分析
邓凯波,霍贵成举
(东北农业大学乳品科学教育部重点实验室,黑龙江哈尔滨150030)
摘要;为探明内蒙古的8株嘴热链球菌的 CRISPR,用PCR方法扩增了其 CRISPR序列,并采用生物信息学方法分
析和预测了重复序列( direct repea,DR)的同源性及二级结构。结果表明:除S4只含有一个 CRISPR结构外,其余7株
嗜热链球薗均检测出3条 CRISPR序列,远高于 CRISPR database公布细茵中具有该结构的比例(46.4%),且分別具特
异性的重复序列(DRI~DR3): CRSPR最长达2853p,最短仅11bp。对DR的二级结构预测发现,DRIへDR3均能
形成回文结构,但茎环大小会有差异:在同源性比对中发现,除多数同属或同种外,供试DR还与个别远缘菌种具
有高同源性,这种现象证明了供试薗株的 CRSPR序列同样存在的水平基因转移,并可能存在其他的进化进程。
关健词:嗜链球茵; clustered regularly interspaced short palindromic repeats( CRISPR):检测;同源性
Detection and Homology Analysis of CRISPR in Streptococcus thermophilus
DENG Kai-bo, HUO Gui-cheng
( Key aboratory of Dairy Scene Minisry of Ecation No ual Nest, Harbin 150030 China
Abstract; CRISPR was recently found to be an acquired immune system widespread in prokaryotes. In order to find out
CRISPRS in Streptococcus thermophilus strains isolated from Inner Mongolia, the CRISPR sequences were obtaine
PCR amplification, and homology and secondary structure of direct repeat (DR)were predicted using bioinformatic
methods. Results showed that all studied strains contained three CRISPR sequences except one in S4, which was much
higher an the ratio(46.4%)in bacteria published on CRISPR database, and three CRISPRS had their specialized direct
repeats(DRI-DR3) The longest CRISPR was 2853 bp, and the shotest was only 101 bp. According o the prediction of
econmy stucture a alinome w e d in D eevel although he sizes of em-loops were different
or homology analysi, DR demonstated high similarity with veral individual species of istant relationships like those in
the same genus or species, which suggested that the CRISPRS of tested strains also had the characteristic of horizontal gene
transfer(H(") as well as the possibility of other evolutionary process
Key words: Streptococcus thermophiles: CRISPR; detection homology
中图分类号:TS201.3:Q939.117
文献标志码:A
文章编号:1002-66302013)03-0153-05
自古以来,乳酸菌就是人们厂广泛使用的一类益生蘭。21~48bp的重复序列和其间插入的相似长度的非重复间
现代工业中,益生菌发酵制品种类繁多,很多乳酸歯被用隔序列组成。目前,嗜热链球菌 CRSSPR序列结构和作
作发酵剂应用于工业生产,其中热链球茵( Streptococcus用机理方面的研究仅在 Streptococcus thermophilus DGCC
thermophilus)为应用最广泛的乳酸菡之ー。然而,由于噬710中最为详尽9,我国尚无相关报导。探明我国嗜热
体污染而导致的生产失败已造成了重大的经济损失。尽链球菌中的 CRSPR序列结构,对其进化研究以及今后噬
管研究者们已采取了许多手段,但收效甚微。
菌体抗性突变菌株的构建都具有重大意义。
规律成簇的间隔回文重复( clustered regularly
interspaced short palindromic repeats, CRISPR)以“重复
材料与方法
序列-间隔区( repeat-spaccr)”为单元组成了原核生物基因
组上的一段非编码区,是专门针对噬菌体及质粒等外源1.1材料与试剂
基因的获得性免疫系统。 CRIPR序列的典型结构为
8株嗜热链球菌く. thermophilus)S0、S4、S06、S07
收稿日期:2011-10-28
基金项目:国家自然科学基金面上项目(31171717):教育部“长江学者和创新团队发展计划”项目(IRT0959)
作者简介:邓凯波(1983),女,博士研究生,研究方向为乳酸菌生物技术。E-mal:keppelred@yahoo.com,cn
通信作者:霍贵成(1958-),男,教授,博士,研究方向为乳品加工与食品微生物。E-mail:chuo(@vip.0451.com
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