Probiotic characteristics and whole genome analysis of Bacillus siamensis CML548 from chicken

Abstract:

[Background] Bacillus is attractive for use as probiotic supplement in animal feed. With potent antimicrobial activity, Bacillus siamensis has drawn wide attention. [Objective] whole-genome sequencing and bioinformatics analysis were applied to explore the probiotic characteristics of the chicken-derived B. siamensis CML548 and clarify the antibacterial and potential probiotic mechanisms of this strain. [Methods] The antimicrobial activity, enzyme production, and tolerance to acid and bile salt were tested with the Oxford cup and spread plate method, respectively. The whole genome was sequenced by Illumina HiSeq 2500, followed by functional annotation and bioinformatic analysis of the genome. [Results] In vitro experiment suggested that this strain had probiotic features: inhibiting the growth of pathogenic Escherichia coli, Salmonella Typhimurium, and Clostridium perfringens, highly tolerating acid and bile salt, and producing protease, amylase, and cellulase. The genome of CML548 was 4 061 741 bp, with 3 961 coding genes and GC content of 46.07%. A total of 1 693, 2 704, 3 413, 186, 67, 1, and 5 genes were respectively annotated to GO, KEGG, COG, CAZy, DBAASP, CARD, and VFDB. antiSMASH predicted multiple gene clusters involved in the synthesis of secondary metabolites. In addition, CML548 contained an antibacterial protein-encoding gene tasA. The genome information was submitted to NCBI and the GenBank accession number is PRJNA836999. [Conclusion] CML548 is a candidate probiotic, which has the potential to be used as a feed additive.

Key words:Bacillus siamensis;probjotic characteristics;genome;antimicrobial activity