一株羊源巨大芽孢杆菌BM24的分离鉴定及安全性评价  

Isolation,Identification and Safety Evaluation of a Sheep-Derived Bacillus megaterium BM24

作　　者：贾盛 候萌 陈伟丽 戴宗茂 彭啟敏 石蕊 王旭翔 谢怀茹 肖莹 王金泉[1] JIA Sheng;HOU Meng;CHEN Weili;DAI Zongmao;PENG Qimin;SHI Rui;WANG Xuxiang;XIE Huairu;XIAO Ying;WANG Jinquan(College of Animal Medicine,Xinjiang Agricultural University,Urumqi 830052,China;Urumqi County Agricultural Products Quality and Safety Testing Centre,Urumqi 830036,China)

机构地区：[1]新疆农业大学动物医学学院,乌鲁木齐830052 [2]乌鲁木齐县农产品质量安全检测中心,乌鲁木齐830036

出　　处：《动物营养学报》2024年第9期6083-6094,共12页CHINESE JOURNAL OF ANIMAL NUTRITION

基　　金：国家自然科学基金项目(32160823);新疆农业大学校级研究生科研创新项目(XJAUGRI2023033)。

摘　　要：本试验旨在评估一株从健康细毛羊粪便中分离得到的巨大芽孢杆菌BM24的体外益生潜力及体内安全性。采集饲养过程中没有添加抗生素的健康新疆细毛羊的新鲜粪便,先通过形态学鉴定、生化鉴定、16S rRNA测序,初步获得羊源芽孢杆菌菌株,后续通过对酸和高浓度胆盐环境的耐受性,以及菌株的体外抗菌能力、耐药性、溶血活性和生长曲线等方面的检测,初步判断分离出的芽孢杆菌菌株的体外安全性,最后进行小鼠体内试验,评估其安全性。结果表明:1)初步分离得到1株羊源芽孢杆菌,结合生化鉴定和测序结果确定为巨大芽孢杆菌,将其命名为巨大芽孢杆菌BM24;2)该菌株可在pH=1.0条件下存活,0.3%胆盐培养4 h后存活率为49%,在15种常见抗生素中对12种抗生素高度敏感,对常见腹泻致病菌沙门氏菌和大肠杆菌抑制效果较好,无溶血活性;3)该菌株在37℃培养2 h后进入生长对数期,6 h后进入生长平稳期;4)灌胃该菌株后小鼠无死亡、体重变化正常,剖检体腔脏器无眼观病理现象,对肝脏、肾脏、脾脏指数及血细胞指标均无显著影响(P>0.05);腹腔注射该菌株,小鼠体征正常、无死亡现象,体腔脏器无眼观病理变化。综上可知,本试验分离得到的羊源巨大芽孢杆菌BM24具有良好的体外益生潜力,且无急性毒性作用,可作为羊源益生菌的候选菌株。The aim of this study was to evaluate the in vitro probiotic potential and in vivo safety of a strain of Bacillus megaterium BM24 isolated from the feces of healthy fine wool sheep.Collection of fresh faeces from healthy,antibiotic-free Xinjiang fine-haired sheep.The Bacillus strain was initially obtained by morphological identification,biochemical identification and 16S rRNA sequencing.Subsequently,through the detection of Bacillus-tolerance to the environments of acidic and high bile salt concentrations,in vitro antibacterial ability,drug resistance,hemolytic activity and growth curve of the strain,the isolated Bacillus strain was eventually judged to have in vitro safety.Finally,the safety of the isolated Bacillus strain was evaluated by in vivo test in mice.The results showed that:1)a Bacillus strain was preliminarily isolated and named Bacillus megaterium BM24 according to the results of biochemical identification and 16S rRNA sequencing.2)Bacillus megaterium BM24 could survive at pH=1.0,with a survival rate of 49%after 4 h of incubation with 0.3%bile salt.Bacillus megaterium BM24 was highly sensitive to 12 of 15 common antibiotics,had good inhibitory effect on common diarrhea pathogens Salmonella and Escherichia coli,and had no hemolytic activity.3)The growth entered the logarithmic phase after 2 h at 37℃,after 6 h,the growth reached a plateau.4)No death,normal body weight change,and no pathological changes in organs in the body cavity of mice when the Bacillus megaterium BM24 treated by gavage.There were no significant effects on the liver,kidney,spleen,organ indexes and blood cell indexes(P>0.05);no death,normal vital signs and no pathological changes in the organs in body cavity of mice at the Bacillus megaterium BM24 treated by intraperitoneal injection.In summary,the sheep-derived Bacillus megaterium BM24 isolated in this experiment has terrific in vitro probiotic potential without acute toxic effect,which can be used as a candidate strain of sheep probiotics.

关 键 词：巨大芽孢杆菌 益生菌 细毛羊 分离鉴定 安全性 

分 类 号：S816[农业科学—饲料科学]