鸡源暹罗芽孢杆菌CML548的益生特性及全基因组分析

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

摘要:

【背景】芽孢杆菌是用于动物微生态制剂的重要菌株之一。暹罗芽孢杆菌因具有较强的抑菌活性，近年来受到广泛关注。【目的】对实验室前期分离的鸡源暹罗芽孢杆菌CML548的益生特性进行评价，通过全基因组测序及生物信息学分析，探究其抑菌及潜在的益生机制。【方法】通过牛津杯法、稀释涂布平板法分别对菌株CML548的抑菌和产酶特性、酸和胆盐的耐受性进行研究。使用Illumina HiSeq 2500测序平台进行全基因组测序，并通过多种生物信息学工具和数据库对基因组进行注释和分析。【结果】体外实验表明该菌株具有优良的益生性状：能够有效抑制致病性大肠杆菌、鼠伤寒沙门氏菌、产气荚膜梭菌的生长；能够同时产生蛋白酶、淀粉酶和纤维素酶；具有较高的酸和胆盐耐受性。全基因组测序分析表明菌株CML548的基因组大小为4 061 741 bp，GC含量为46.07%，预测到3 961个编码基因。分别有1 693、2 704、3 413、186、67、1、5个基因被GO、KEGG、COG、CAZy、DBAASP、CARD、VFDB数据库注释；通过antiSMASH预测到16个与次级代谢产物合成相关的基因簇。此外，还发现其含有抗菌活性蛋白编码基因tasA。全基因组序列存储于NCBI的DNA序列数据库(GenBank登录号为PRJNA836999)。【结论】本研究所分离到的暹罗芽孢杆菌CML548是一株潜在的益生菌，有作为新型饲料添加剂的潜力。

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.