Streptococcus thermophilus IMAU20551胞外多糖基因簇及其表达分析  

eps(Exopolysaccharide)Gene Cluster from Streptococcus thermophilus IMAU20551 and Its Expression Analysis

作　　者：乔少婷 代安娜尔 解敏 孙思霖 聂佳莹 丹彤[1] QIAO Shaoting;DAIANNAER;XIE Min;SUN Silin;NIE Jiaying;DAN Tong(Key Laboratory of Dairy Biotechnology and Engineering,Ministry of Education,Inner Mongolia Agricultural University,Hohhot 010018,China)

机构地区：[1]内蒙古农业大学乳品生物技术与工程教育部重点实验室,内蒙古呼和浩特010018

出　　处：《食品科学》2022年第22期136-144,共9页Food Science

基　　金：国家自然科学基金地区科学基金项目(31860448)。

摘　　要：以1株产胞外多糖(exopolysaccharide,EPS)的嗜热链球菌(Streptococcus thermophilus)IMAU20551为研究对象,提取其DNA后采用Illumina HiSeq技术对DNA进行二代基因组重测序,并利用SOAPdenovo软件对其进行组装,通过与RAST、直系同源集、基因本体论、京都基因与基因组百科全书等数据库进行比对,注释基因组中功能基因。发现S.thermophilus IMAU20551基因组全长1725107 bp,共注释出1884个功能基因,其中包含一个长度为19376 bp的完整eps基因簇,该基因簇中与EPS合成相关的基因共有18个,主要包括epsA、epsB、epsC、epsD、epsE、eps1F、eps2F、epsJ、wzx、epsP和epsX等,这些基因分别对EPS的合成、组装以及转运输出进行调控。另一方面,利用实时聚合酶链式反应对S.thermophilus IMAU20551 eps基因簇表达进行验证,发现所有基因均可表达,且除个别糖基转移酶基因外,其他被测基因均在6 h达到最大表达量。本研究介绍了S.thermophilus IMAU20551的基因组特征、eps基因簇及其表达能力,为今后深入研究S.thermophilus EPS基因簇及其表征结构的互作关系奠定基础。DNA was extracted from an exopolysaccharide(EPS)-producing strain of Streptococcus thermophilus IMAU20551,and was sequenced on an Illumina HiSeq platform and the filtrated reads were assembled using the SOAPdenovo software.Functional genes were annotated to the RAST,the Clusters of Orthologous Groups(COG),the Gene Ontology(GO),and the Kyoto Encyclopedia of Genes and Genomes(KEGG)databases.The genome of S.thermophilus IMAU20551 was found to be 1725107 bp in length,and 1884 functional genes were annotated,including a complete eps gene cluster of 19376 bp in length.In total 18 genes related to EPS synthesis were contained in the gene cluster,including epsA,epsB,epsC,epsD,epsE,eps1F,eps2F,epsJ,wzx,epsP and epsX.These genes regulate the synthesis,assembly and transport of exopolysaccharides.Furthermore,real-time PCR was used to verify the expression of the eps gene cluster from S.thermophilus IMAU20551,and it was found that all genes could be expressed.Except for a few glycosyltransferase genes,most of the genes showed maximum expression levels at 6 h.This study lays a foundation for further studies on the interaction between gene clusters and the structures of EPS from S.thermophilus.

关 键 词：胞外多糖 嗜热链球菌 eps基因簇 基因组信息 实时聚合酶链式反应 

分 类 号：TS201.3[轻工技术与工程—食品科学]