乳酸杆菌体外对大肠埃希菌O-78拮抗作用试验

STUDY ON ANTAGONISM TOWARD ESCHERICHIA COLI O-78 BY LACTOBACILLUS IN VITRO

目的 :研究乳酸杆菌体外对大肠埃希菌O 78的拮抗作用。方法 :将乳酸杆菌与大肠埃希菌O 78体外共培养观察拮抗情况及用电镜观察形态变化。结果 :等量同时间接种 ,2 4h内乳杆菌就将大肠埃希菌O 78全部抑杀 ;乳酸杆菌早 2 4h接种 ,4～ 8h内将大肠埃希菌O 78全部抑杀 ;大肠埃希菌O 78早 2 4h接种 ,在 12～ 2 4h内全部被抑杀。电镜观察发现 ,经乳酸杆菌培养液处理 ,大肠埃希菌O 78细胞膜形态发生变化。结论 :本试验中所用乳酸杆菌体外具有抑制杀死大肠埃希菌O 78的作用。

Objective:To investigate whether there is antagonism of Lactobacillus (LAB) toward E.coli O 78 in ivtro or not.Method:LABs and E.coli O 78 were cultured together,then observed the survive of E.coli O 78 and the bacterial cells morphology alteration by TEM.Results:Inoculated LABs and E.coli O 78 at same time and volumes, E.coli O 78 were killed in 24 h. E.coli O 78 were killed in 4 to 8 h and 12 to 24 h,respectly,when inoculated LABs 24 h earlier or later than E.coli O 78.When E.coli O 78 exposed to LAB culture supernatant,an altered cell membrance morphology was observed by TEM.Conclusion:The LABs used in this study had the ability of antagonism toward E.coli O 78.