鸡源地衣芽孢杆菌的分离鉴定及全基因组分析

Isolation,Identification and Genome-wide Analysis of Bacillus licheniformis from Chicken

通过细菌形态学、生理生化特征和16S rRNA测序等方法,鉴定从蛋鸡粪便中分离出的地衣芽孢杆菌菌株。以体外法对分离株Bacillus licheniformis LH96进行益生效果评价,发现其在14 h达到稳定期,具有良好的耐热能力,在pH 2.5~5.0、0.1%~0.3%胆盐浓度和模拟人工胃肠液等条件下,均有着良好的耐受性。B.licheniformis LH96具有产多种短链脂肪酸的能力,其中产乙酸的能力最强。耐抗生素试验结果显示,菌株对阿奇霉素、克林霉素和红霉素具有耐药性。同时,通过基因组装得到了B.licheniformis LH96的全基因组信息,菌株基因组大小为4187148 bp,G+C含量为46.18%,包含了4263个蛋白质编码序列。菌株中存在大量与碳水化合物代谢有关的基因,以及糖苷水解酶、多糖裂解酶和碳水化合物酯酶等,这些代谢途径中的酶可以帮助分解鸡不能消化的淀粉、纤维素、果胶等营养物质。研究结果为进一步阐明其益生菌特性的功能机制提供了遗传学基础。

Through a variety of methods,such as bacterial morphology,physiological and biochemical characteristics and 16S rRNA sequencing,the strain isolated from layer feces was identified as Bacillus licheniformis.The probiotic effect of Bacillus licheniformis LH96 was evaluated by the in vitro method,and it was found that it reached a stable period at 14 h,and it had good heat resistance.It had good tolerance under the conditions of pH 2.5-5.0,0.1%-0.3%bile salt concentration and simulated artificial gastrointestinal fluid.B.licheniformis LH96 had the ability to produce a variety of short-chain fatty acids,of which the ability to produce acetic acid was the strongest.The results of the antibiotic resistance test showed that the strain was resistant to azithromycin,clindamycin and erythromycin.At the same time,the whole genome information of B.licheniformis LH96 was obtained by gene assembly.The results showed that the strain was 4187148 bp,with a G+C content of 46.18%and a total of 4263 protein coding sequences.The strain contains a large number of genes related to carbohydrate metabolism,as well as glycoside hydrolases,polysaccharide lyases and carbohydrate esterases.The enzymes in these metabolic pathways can help break down nutrients such as starch,cellulose and pectin that chickens cannot digest.The results provide a genetic basis for further elucidating the functional mechanism of its probiotic properties.