基于基因组学分析嗜热链球菌KLDS SM的蛋白质水解系统和氨基酸合成途径  

Genomic Studies of Proteolysis System and Amino Acid Biosynthesis Pathway in Streptococcus thermophilus KLDS SM

作　　者：李柏良[1] 丁秀云[1,2] 靳妲 刘飞 蒙月月[1] 李娜 赵莉[1] 霍贵成[1] LI Bailiang;DING Xiuyun;JIN Da;LIU Fei;MENG Yueyue;LI Na;ZHAO Li;HUO Guicheng(Key Laboratory of Dairy Science,Ministry of Education,Northeast Agricultural University,Harbin 150030,China;Guangzhou Genedenovo Biotechnology Co.Ltd.,Guangzhou 510000,China)

机构地区：[1]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 [2]广州基迪奥生物科技有限公司,广东广州510000

出　　处：《食品科学》2018年第18期120-126,共7页Food Science

基　　金："十三五"国家重点研发计划重点专项(2017YFD0400303);国家自然科学基金青年科学基金项目(31401512)

摘　　要：为从遗传水平上探究嗜热链球菌KLDS SM蛋白质水解和氨基酸合成的能力,首先基于Illumina Hiseq 2500与Pacbio RSII测序平台对嗜热链球菌KLDS SM进行全基因组测序并绘制基因组图谱;随后从胞外蛋白酶、转运系统、胞内肽酶以及氨基酸合成等方面所涉及的基因进行生物信息学分析;最后对15株已完成全基因组测序的嗜热链球菌的氨基酸合成能力进行比较基因组学研究。结果表明:菌株KLDS SM的基因组由一个1 856 787 bp环状染色体组成,GC含量为39.08%,含有1 732个蛋白质编码基因;菌株KLDS SM具有完整的蛋白水解系统和8种氨基酸的合成能力;15株嗜热链球菌在氨基酸合成方面上相对保守,仅在组氨酸合成途径存在较大的差异。本研究为该菌株氮代谢能力的挖掘提供了理论依据,并在将其开发为发酵剂方面上具有一定指导意义。The purpose of this study was to gain genomic insights into the proteolysis system and amino acid biosynthesis in Streptococcus thermophilus KLDS SM.Firstly,whole genome sequencing was performed using combination of Illumina Hiseq 2500 sequencing and Pacific Biosciences RSII sequencing and the circular genomic map was constructed;subsequently,in silico bioinformatics analysis was carried out with respect to extracellular proteinase,peptide transport system,intracellular peptidase and amino acid biosynthesis;finally,comparative genomics of amino acid biosynthesis between strain KLDS SM and 14 other S.thermophilus strains,all of which have had the whole genome sequenced,was performed.The results showed that the genome of S.thermophilus KLDS SM consisted of a circular chromosome(1 856 787 bp)with GC content of 39.08%.A total of 1 732 protein-encoding genes were predicted.S.thermophilus KLDS SM had a complete proteolytic system and could biosynthesize eight amino acids.Furthermore,comparative genomics analysis showed that the amino acid biosynthesis abilities of 15 strains were relatively conservative except for a large difference in histidine biosynthesis among different strains.The results of this study can provide a theoretical basis for better understanding of nitrogen metabolism in S.thermophilus KLDS SM and are of important significance to exploiting it as a starter culture.

关 键 词：嗜热链球菌 基因组 生物信息分析 蛋白质水解 氨基酸合成 

分 类 号：R151.1[医药卫生—营养与食品卫生学]