北极狐源唾液乳杆菌ZJBF005的分离鉴定与体外益生功能的评价

Isolation and Identification of Lactobacillus salivarius ZJBF005 from Alopex lagopus and Its Probiotic Function Evaluation in Vitro

本研究旨在从健康北极狐肠道中分离和鉴定具有益生菌潜能的乳酸菌,并对其体外益生功能进行评价。对分离菌株进行生理生化和16S rRNA鉴定,测定其生长曲线、产酸和耐酸曲线,测定该菌的胆盐耐受性以及在人工胃液和人工肠液中的存活率,分别采用牛津杯琼脂扩散法和纸片扩散法检测该菌的抗菌活性和抗生素敏感性。最后选取20只雌性昆明小鼠,随机分为2组(每组10只),对照组灌胃生理盐水,试验组灌胃唾液乳杆菌(1×10^(9) CFU/mL),试验期7 d。结果表明:结合16S rRNA和生理生化鉴定结果将其命名为唾液乳杆菌ZJBF005,该菌在MRS培养基中生长迅速,具有较强的产酸能力;在pH 4~7培养液之间生长良好,培养液pH低于2生长受到抑制;在人工胃液、人工肠液中培养3 h后的存活率分别为40.96%和86.70%;可在0.2%的胆盐环境中生长;可抑制沙门氏菌和金黄色葡萄球菌的生长;对四环素、庆大霉素、万古霉素、磷霉素、阿奇霉素、甲氧苄啶和甲硝唑等抗生素不敏感;灌胃后的小鼠体重变化正常、无死亡、剖检无病理性变化。综上所述,来自健康北极狐肠道的唾液乳杆菌ZJBF005具有良好的益生菌特性,可作为益生菌的备选菌株。

The objective of this study was to isolate and characterize lactic acid bacteria with probiotic potential in Alopex lagopus’s gut,and evaluate its probiotic function evaluation in vitro.The isolated strain identified by physiological,biochemical and 16S rRNA identification,measured its growth curve,acid production and acid resistance curves,bile salt tolerance and survival rate in artificial gastric juice and artificial intestinal juice were measured,the antibacterial activity and antibiotic sensitivity of the bacteria were detected by oxford cup agar diffusion test and disk diffusion test,respectively.Finally,twenty female Kunming mice were randomly divided into two groups,the control group was given normal saline intragastrically,and the experimental group was given Lactobacillus salivarius(1×10^(9) CFU/mL),the experiment lasted for 7 days.The results showed that the strain was named Lactobacillus salivarius ZJBF005 according to 16S rRNA and physiological and biochemical identification results,it had a strong acid-producing ability and growth rapidly in the MRS medium;it could maintain good growth in the culture-medium with pH 4 to 7,while couldn’t grow in the culture-medium less than pH 2;the survival rate after incubation in artificial gastric juice and artificial intestinal juice for 3 h were 40.96%and 86.70%,respectively;it could grow in 0.2%bile salt environment;it could inhibit the growth of Salmonella and Staphylococcus aureus;it was not sensitive to antibiotics such as tetracycline,gentamicin,vancomycin,fosfomycin,azithromycin,trimethoprim and metronidazole,etc;the body weight change of mice after intragastric administration was normal,no death,and no pathological change in autopsy.In conclusion,the Lactobacillus salivarius ZJBF005 in healthy Alopex lagopus’s gut has pretty probiotic properties,it can be preliminarily determined as probiotic candidates.