中国畜牧兽医2024，Vol.51Issue(7)：3020-3029,10.DOI:10.16431/j.cnki.1671-7236.2024.07.027
屎肠球菌FDT2的分离鉴定及抑菌特性研究
Isolation,Identification and Antimicrobial Properties of Enterococcus faecium FDT2
摘要
Abstract
[Objective]The purpose of this experiment was to isolate and identify Enterococcus faeciums isolates from yak faeces and conduct in vitro antibacterial studies,in order to screen probiotics with excellent antibacterial properties.[Method]In this experiment,Enterococcus spp.were isolated from faeces of healthy yaks in Qinghai province utilizing MRS medium,the strains were identified by combining morphology and molecular biology and conduct antibacterial research.The supernatants of the strains were isolated by fermentation filtration,and the corresponding antibacterial effect was observed using punching method.The antibacterial substances were analyzed by changing pH,adding catalase,pepsin and trypsin,and the effects of temperature and pH on the fermentation supernatants were explored.[Result]The results of morphology and phylogenetic tree analysis showed that the two new isolates(FDT2 and D2)belonged to Enterococcus faecium.The antibacterial experiment results showed that Enterococcus faecium FDT2 had inhibitory effect on all five pathogenic bacteria,and the inhibitory effects on enterotoxigenic Escherichia coli K88 and Escherichia coli ATCC 43888 were more stronger,while D2 had no inhibitory effect on all five pathogenic bacteria.The acid excretion test results proved that the acidic substance in the fermentation supernatant of Enterococcus faecium FDT2 did not have antibacterial effects.The experiment of adding catalase proved that hydrogen peroxide existed in the bacteriostatic substance and played partly bacteriostatic effect.After addition of pepsin and trypsin,it was found that the diameter of inhibition zone was extremely significantly lower than that of control group(P＜0.01),indicating that antibacterial substances contained bacteriocin and played a major role in antibacterial effects.With the gradual increase of temperature,the antibacterial activity of Enterococcus faecium FDT2 decreased,and it remained antibacterial activity at 100 ℃,indicating its strong thermal stability.With the increase of pH,the bacteriostatic activity of Enterococcus faecium FDT2 decreased gradually,which also indicated that bacteriocin had strong activity in acidic environment.[Conclusion]Two strains of bacteria were isolated in the experiment,among which Enterococcus faecium FDT2 had good bacteriostatic properties and contained bacteriocin and other antibacterial substances,and it was necessary to further study on the bacteriocin of Enterococcus faecium FDT2.关键词
屎肠球菌/鉴定/形态学/抑菌性Key words
Enterococcus faecium/identification/morphology/antimicrobial activity分类
农业科技引用本文复制引用
张晓勇,吕舒婷,陈曼,殷宏,李有全,蓝伟,王雅,劳健龙,李志,贾丹,孔祥颖,胡凯茵,温咏森..屎肠球菌FDT2的分离鉴定及抑菌特性研究[J].中国畜牧兽医,2024,51(7):3020-3029,10.基金项目
广东海洋大学科研启动费(060302052201) （060302052201）
大通县科技计划项目(2023-ZB-1) （2023-ZB-1）
宁夏回族自治区重点研发计划项目(2022BBF03024) （2022BBF03024）
减抗替抗益生菌制剂示范推广 （）
国家肉牛牦牛产业技术体系(CARS-37) （CARS-37）
"十三五"重点研发计划(2018YFD0501804、2017YFD0501200) （2018YFD0501804、2017YFD0501200）
