Genome sequencing and comparative genomics analysis of Bacillus subtilis N2-10

Abstract:

[Background] With strong bacteriostatic activity, Gram-positive Bacillus subtilis N2-10 produces diverse hydrolases such as cellulase, thus showing huge potential in feed fermentation. [Objective] The whole genome of N2-10 was sequenced and the genes related to the synthesis of the secondary metabolites were analyzed. Based on comparative genomics, the difference between N2-10 and the model strain was dissected. The findings are expected to lay a theoretical basis for clarifying the bacteriostatic and probiotic mechanisms of this strain. [Methods] The genome of N2-10 was sequenced by Illumina NovaSeq and PacBioSequel, followed by genome assembly, gene prediction, and functional annotation. The differences between N2-10 and a model strain were analyzed by comparative genomics. [Results] The genome of N2-10 is 4 036 899 bp, with GC content of 43.88%. It has 4 163 coding genes with the total length of 3 594 369 bp, and the total length of the coding region accounts for 89.1% of the total genome length. In detail, it has 85 tRNA genes, 10 5S rRNA genes, 10 16S rRNA genes, 10 23S rRNA genes, 2 CRISPR-Cas sequences, and 6 gene islands. Moreover, this strain was also found to have a prophage. In addition, 3 048, 3 177, 3 894, and 145 genes were annotated in GO (gene ontolog), COG (clusters of orthologous groups of proteins), KEGG (Kyoto encyclopedia of genes and genomes), and CAZy (carbohydrate-active enzymes) databases, respectively. At the same time, 10 gene clusters for the synthesis of secondary metabolites were predicted, including biosynthesis gene clusters rhizocticin A, bacillaene, fengycin, bacillibactin, subtilosin A, and bacilysin and 3 unknown gene clusters. Comparative genomics analysis showed that N2-10 had high homology with B. subtilis 168. [Conclusion] Through genome sequencing, we unveiled the genetic information of N2-10, providing a reference for further understanding the secondary metabolites of this stain and further development and utilization of it.

Key words:Bacillus subtilis;genome sequencing;genome maps;comparative genomics analysis