不同来源植物乳杆菌基因组的比较分析

目的 对分离自母乳、婴儿肠道的植物乳杆菌进行全基因组测序,分析菌株间亲缘关系和细菌素合成相关基因。方法 本研究采用Illumina高通量测序平台对不同来源的植物乳杆菌进行全基因组测序,质控过滤后的数据经Unicycler组装获得基因组精细图,通过比对COG、CAZy数据库对功能基因进注释,并借助BAGEL4等生物信息学分析工具鉴别植物乳杆菌素合成相关的基因簇,分析不同来源植物乳杆菌的益生潜力。结果 本研究5株植物乳杆菌基因组平均GC含量为44 %,母乳源植物乳杆菌基因数量多于婴儿肠道源菌株。进化树和ANI分析结果显示,分离所得菌株具有较高的同源性,相同来源的菌株更倾向于聚类到一个分支。功能注释结果显示,母乳源菌株与肠道源菌株相比拥有更多编码碳水化合物代谢的基因,且拥有完整的产植物乳杆菌素基因簇。结论 植物乳杆菌基因组GC含量、功能基因数目及产细菌素基因簇结构等与分离源有一定的关联,母乳源植物乳杆菌更适于作为潜在益生菌的候选菌株,本研究为益生菌的益生潜力研究提供了遗传学基础。

Comparative analysis of Lactobacillus plantarum genome isolated from different sources

Objective To sequence the whole genome of Lactobacillus plantarum isolated from human milk and infant intestine, and analyze the genetic relationship and bacteriocin synthesis related genes among strains. Methods Illumina high-throughput sequencing platform was used to complete the whole genome sequencing. The quality control filtered data were assembled by Unicycler to obtain a genome fine map, and the functional genes were annotated by comparing COG and CAZy databases. With the help of bioinformatics analysis tools such as BAGEL4, gene clusters related to phytolactobacilli synthesis were identified, and the prebiotic potential of different sources of phytolactobacilli was analyzed. Results The average of guanine and cytosine (GC) content of 5 strains of Lactobacillus plantarum genome was 44%, and the gene numbers of breast milk origin strains were higher than infant intestinal origin strains. The results of phylogenetic tree and average nucleotide identity analysis showed that all the isolates of Lactobacillus plantarum with high homology, and the isolates from the same source tended to cluster into the same branch. The functional annotation results showed that breast milk origin strains had more genes associated with carbohydrate metabolism than those from infant intestines, and had a complete Lactobacillus plantarum bacteriocins-producing gene cluster. Conclusion The GC content, number of functional gene and the structure of bacteriocin gene cluster, etc. of Lactobacillus plantarum genome are correlated with the isolated source. Lactobacillus plantarum from breast milk is more suitable as a candidate strain of potential probiotics. This study provides a genetic basis for the study of probiotic potential of probiotics.