【作者】 孙悦欣； 赵乾； 李伟程； 张和平；

【Author】 Sun Yuexin;Zhao Qian;Li Weicheng;Zhang Heping;Key Laboratory of Dairy Biotechnology and Engineering,Ministry of Education,Inner Mongolia Agricultural University;Key Laboratory of Dairy Processing,Ministry of Agriculture and Rural Affairs;Key Laboratory of Dairy Biotechnology and Engineering;

【机构】 内蒙古农业大学乳品生物技术与工程教育部重点实验室； 农业农村部奶制品加工重点实验室； 乳品生物技术与工程重点实验室；

【摘要】 罗伊氏粘液乳杆菌(Limosilactobacillus reuteri)是常见的益生乳酸菌菌种,其广泛存在于人类和动物的肠道、乳制品、发酵面团和肉制品中。依托内蒙古农业大学乳酸菌种质资源库,以分离自动物源、食物源和人源的79株L.reuteri为研究对象进行基因组测序和组装,结合NCBI已公开的102株菌株基因组数据,采用比较基因组学方法解析L.reuteri系统发育关系和功能基因组特征。结果发现,食物源L.reuteri的基因组大小为2.01 ± 0.75 Mb,GC含量为38.77 %± 0.17%。与人源和动物源菌株相比,食物源菌株基因组较小且GC含量较大。系统发育分析结果显示,相同分离源的菌株呈现明显的聚集趋势,表明相同分离源的菌株可能拥有共同的进化历程。碳水化合物活性酶(CAZy)注释结果发现不同分离源菌株的GH(糖苷水解酶)家族存在差异显著,动物源菌株的CAZy种类丰富且存在特有的CAZy家族,食物源菌株相较于其他分离源菌株拥有较多的GT2和GT4拷贝数,表明不同分离源的CAZy特征不同。耐药基因注释结果发现动物源菌株中具有大量的抗性基因,而食物源与人源菌株抗性基因较少,可能由于动物饲养过程中会添加抗生素。综上,不同来源L.reuteri的遗传背景和功能基因组特征与生存环境密切相关,表明其适应不同环境发生了适应性进化,本研究为解析L.reuteri遗传背景提供了新的观点。更多还原

【Abstract】 As a common probiotic lactic acid bacteria,Limosilactobacillus reuteri exists extensively in human and animal intestines,dairy products,fermented dough and meat products.Based on the lactic acid bacteria collect center of Inner Mongolia Agricultural University,79 strains of L.reuteri isolated from animal,food and human were sequenced and assembled.Combined with the genome data of 102 strains published in NCBI,the phylogenetic relationship and functional genomic characteristics of L.reuteri were analyzed by comparative genomics.The results showed that the genome size of L.reuteri was 2.01 ± 0.75 Mb,and the GC content was 38.77±0.17 %.Compared with human and animal strains,the genome of food source strains had smaller genome and larger GC content.The results of phylogenetic analysis showed that the strains of the same isolation source showed a clear trend of aggregation,indicating that they had common evolutionary history.The results of carbohydrate active enzyme(CAZy) annotation showed that there were significant differences in the GH(glycoside hydrolase) family of different niche isolates.There were abundant CAZy species and unique CAZy family in animal-derived strains.The L.reuteri of food source had more GT2 and GT4 copies than other isolates,indicating that the CAZy characteristics of different niche isolates were different.The results of drug resistance gene annotation showed that there were a large number of resistance genes in animal-derived strains,while there were fewer strains in food-derived and human-derived strains.It may be due to the addition of antibiotics during animal feeding.In conclusion,the genetic background and functional genome characteristics of L.reuteri from different sources are closely related to the living environment,indicating that the adaptive evolution of L.reuteri has occurred in different environments.This study provides a new perspective for the analysis of the genetic background of L.reuteri.更多还原