鹅粪便中副干酪乳酸杆菌和枯草芽孢杆菌的分离及鉴定

Isolation and identification of Lactobacillus paracasei and Bacillus subtilis in goose feces

目的 分离北方白鹅粪便中的副干酪乳酸杆菌和枯草芽孢杆菌,并进行鉴定。方法 收集30只52周龄北方白鹅的粪便,通过特异性培养基培养,分离获得副干酪乳酸杆菌和枯草芽孢杆菌菌株,分别编号为S00834-8和IS00439-2,并进行16S DNA测序鉴定。将获得的两2株菌株于不同培养时间(0、2、4、6、8、10、12、14、16、18、20、22、24、36和48 h)、温度(34、36、37、38、40℃)、pH(5.5、6.0、6.5、7.0、7.5和8.0)条件下培养,通过紫外可见分光光度计测定A_(600),评价菌株的生长特性。同时检测菌株的耐酸耐胆盐特性(pH为2.0、2.5、3.0、3.5、7.0,胆盐浓度为0、0.3%、0.5%、1.0%、1.5%)及对抗生素的耐受性。结果 获得的S00834-8和IS00439-2菌株分别为副干酪乳酸杆菌亚种耐受性H和枯草芽孢杆菌KA9。S00834-8菌株最佳培养条件为:于37℃,用pH为6.0的培养基培养12 h;具有良好的耐胆汁和耐胃酸的能力;对哌拉西林、诺氟沙星、阿米卡星、庆大霉素和四环素中度敏感,对左氟沙星、链霉素、氯霉素敏感。IS00439-2菌株最佳培养条件为:于36℃,用pH为7.5的培养基培养8 h;具有良好的耐胆汁和耐胃酸的能力;对左氟沙星和四环素中度敏感,对哌拉西林、诺氟沙星、链霉素和氯霉素敏感。结论 鹅源副干酪乳酸杆菌亚种耐受性H和枯草芽孢杆菌KA9具有良好的耐酸、耐胆盐特性,有望成为鹅源微生态制剂的候选菌株。

Objective To isolate and identify Lactobacillus paracasei and Bacillus subtilis from feces of northern white geese.Methods Lactobacillus paracasei and Bacillus subtilis,numbered S00834-8 and IS00439-2 respectively,were isolated from feces of 3052-week-old northern white geese and cultured in specific medium,and identified by 16S DNA sequencing.The two strains were cultured for different time duration(0,2,4,6,8,10,12,14,16,18,20,22,24,36 and 48 h),at different temperature(34,36,37,38 and 40℃)and pH(5.5,6.0,6.5,7.0,7.5 and 8.0).The growth characteristics of the strains were evaluated according to the A_(600) values measured by UV-Vis spectrophotometer.At the same time,the acid and bile salt tolerance(pH 2.0,2.5,3.0,3.5 and 7.0,bile salt concentration 0,0.3%,0.5%,1.0%and 1.5%)and the antibiotic tolerance were tested.Results The strains S00834-8 and IS00439-2 were Lactobacillus paracasei subspecies tolerance H and Bacillus subtilis KA9,respectively.The strain S00834-8 cultured under the optimum condition of the culture medium with pH 6.0,at 37℃,for 12 h,had good bile resistance and gastric acid resistance,which was moderately susceptible to piperacillin,norfloxacin,amikacin,gentamicin and tetracycline,and susceptible to levofloxacin,streptomycin and chlor-amphenicol.The strain IS00439-2 best cultured in the culture medium with pH 7.5,at 36℃,for 8 h,showed good bile resistance and gastric acid resistance,which was moderately sensitive to levofloxacin and tetracycline,while sensitive to piperacillin,norfloxacin,streptomycin and chloramphenicol.Conclusion Goose-derived Lactobacillus paracasei subspecies tolerance H and Bacillus subtilis KA9 have good acid resistance and bile salt resistance,which are expected to be candidate strains for goose-derived microecological preparations.