关键词: 发酵食品；赖氨酸芽孢杆菌；VB12；全基因组测序；基因功能注释

Abstract: In order to explore the mechanism for the production of vitamin B12 (VB12) 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 4 690 817 bp in length with an average GC content of 37.21%, and 4 756 protein-encoding genes, 34 rRNAs, and 111 tRNAs were predicted. A total of 3 095, 3 182, 4 374, 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 VB12 . 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 B12 biosynthesis in fermented foods.

Key words: fermented food; Lysinibacillus; vitamin B12; whole genome sequencing; gene functional annotation