Abstract：
This study aims to screen for potential probiotic lactic acid bacteria from the intestines of meat-type pigeon squabs. Ligilactobacillus salivarius YZU37 was identified as the best comprehensive performed strain. Being acid- and bile salt-tolerant, it displayed growth-inhibition activities against Staphylococcus aureus ATCC25923, Escherichia coli ATCC25922, and Salmonella typhimurium SL1344, exhibited sensitivity to 6 commonly used antibiotics, and endowed with good cell surface hydrophobicity, auto-aggregation property, and anti-oxidant activities. Results of in vitro experiments indicated that the bacteriostatic effects of this strain were related to the production of proteinaceous substances that depend on acidic conditions. Whole-genome sequencing of L. salivarius YZU37 was performed to elucidate the genetic basis underlying its probiotic potential. Pangenome analysis of L. salivarius YZU37 and other 212 L. salivarius strains available on NCBI database revealed a pigeon-unique gene coding choloylglycine hydrolase (CGH), which had higher enzyme-substrate binding affinity than that of the common CGH shared by L. salivarius strains of other sources. Annotation of the functional genes in the genome of L. salivarius YZU37 revealed genes involved in responses to acid, bile salt, heat, cold, heavy metal, and oxidative stresses. The whole genome analysis also revealed the absence of virulence and toxin genes and the presence of 65 genes distributed under 4 CAZymes classes, 2 CRISPR-cas regions, and 3 enterolysin A clusters which may confer the acid-dependent antimicrobial potential of L. salivarius YZU37. Altogether, our results highlighted the probiotic potential of L. salivarius YZU37. Further in vivo investigations are required to elucidate its beneficial effects on pigeons.
摘要：
本研究旨在从肉型鸽子的肠道中筛选潜在的益生菌乳酸菌。唾液杆菌YZU37被鉴定为综合表现最好的菌株。耐酸和耐胆汁盐，它对金黄色葡萄球菌ATCC25923，大肠杆菌ATCC25922和鼠伤寒沙门氏菌SL1344表现出生长抑制活性，对6种常用抗生素表现出敏感性，并具有良好的细胞表面疏水性，自动聚合属性，和抗氧化活性。体外实验结果表明，该菌株的抑菌作用与依赖于酸性条件的蛋白质物质的产生有关。进行唾液乳杆菌YZU37的全基因组测序以阐明其益生菌潜力的遗传基础。NCBI数据库上可用的唾液乳杆菌YZU37和其他212唾液乳杆菌菌株的全基因组分析揭示了一种鸽子独特的基因编码绒毛甘氨酸水解酶（CGH），与其他来源的唾液乳杆菌菌株共享的常见CGH相比，具有更高的酶-底物结合亲和力。唾液乳杆菌YZU37基因组中的功能基因的注释揭示了参与酸反应的基因，胆汁盐,热,冷,重金属,和氧化应激。全基因组分析还显示缺乏毒力和毒素基因，并且存在分布在4个CAZymes类别下的65个基因，2个CRISPR-CAS区域，和3个肠溶素A簇，它们可能赋予唾液乳杆菌YZU37的酸依赖性抗菌潜力。总之,我们的结果强调了唾液乳杆菌YZU37的益生菌潜力。需要进一步的体内研究来阐明其对鸽子的有益作用。
