1株产VB_(12)球形赖氨酸芽孢杆菌C5.1的分离、全基因组测序及分析

Isolation and Whole Genome Sequencing Analysis of VB_(12)-Producing Lysinibacillus sphaericus Strain C5.1

为深入探究球形赖氨酸芽孢杆菌C5.1(Lysinibacillus sphaericus C5.1)菌株产VB_(12)的作用机制,利用PacBio Sequel和Illumina NovaSeq PE150相结合的方法对C5.1菌株进行全基因组测序,并对测序数据进行拼接、基因预测及功能注释。结果表明,C5.1菌株基因组为一个环状DNA,不含质粒,大小为4690817 bp,GC含量为37.21%,预测得到4756个编码基因,111个tRNA基因和34个rRNA基因。通过基因本体论、直系同源集、京都基因与基因组百科全书和转运蛋白分类数据库对C5.1菌株基因组进行注释分析,分别匹配到3095、3182、4374个和397个基因。进一步分析发现C5.1菌株基因组中包含从尿卟啉原Ⅲ逐步转化合成VB_(12)的关键酶。本研究为解析C5.1菌株在臭腐乳发酵过程中的代谢机理提供遗传信息基础,也为今后开展发酵食品中VB_(12)的生物合成机制研究提供理论支撑。

In order to explore the mechanism for the production of vitamin B_(12)(VB_(12))by Lysinibacillus sphaericus C5.1,the whole genome of this stain was sequenced on the PacBio Sequel and Illumina NovaSeq PE150 platforms.Several bioinformatics methods were then used to assemble the sequence data obtained for gene prediction and functional annotation.The results showed that the genome of strain C5.1 consisted of one circular chromosome without plasmids and was 4690817 bp in length with an average GC content of 37.21%,and 4756 protein-encoding genes,34 rRNAs,and 111 tRNAs were predicted.A total of 3095,3182,4374,and 397 genes were respectively matched to the Gene Ontology(GO),Clusters of Orthologous Groups(COG),Kyoto Encyclopedia of Genes and Genomes(KEGG),and Transporter Classification Database(TCDB).Furthermore,we found that the genome of strain C5.1 contained the genes encoding the key enzymes involved in the conversion of uroporphyrinogen Ⅲ to VB_(12).These results could provide an important foundation for studies on the metabolic pathways of L.sphaericus C5.1 during the fermentation of stinky tofu and also provide theoretical support for exploring the mechanism of vitamin B_(12)biosynthesis in fermented foods.