论文部分内容阅读
目的:探讨应用莫匹罗星锂盐改良MRS(MUP-MRS)进行双歧杆菌计数的最佳条件。方法:使用双歧杆菌和乳酸菌各4株对不同剂量MUP-MRS进行性能测试;对5份含乳双歧杆菌的市售样品进行乳双歧杆菌计数;并观察双歧杆菌在不同培养时间的生长情况。结果:当莫匹罗星锂盐(L i-MUP)为0.5 mg~1.0 mg/100 m l时,双歧杆菌生长率在0.98~1.19间,两歧双歧杆菌不生长;L i-MUP大于2.0 mg/100 m l时,双歧杆菌均不生长。5份样品中,L i-MUP在0.5 mg~0.75 mg/100 m l时,乳双歧杆菌计数1.0×106~3.9×108CFU/m l,生长良好;非目标乳酸菌完全受抑制(植物乳杆菌除外)。L i-MUP在1.0 mg/100 m l时,乳双歧杆菌不生长。双歧杆菌培养48 h±2 h,菌落细少;培养72 h±2 h,形成易于计数的菌落。结论:用MUP-MRS琼脂进行双歧杆菌计数时,L i-MUP的添加剂量可选0.5 mg~0.75 mg/100 m l,培养时间选择72 h±2 h。
Objective: To investigate the optimal conditions for counting Bifidobacterium with Mupirocin sodium salt modified MRS (MUP-MRS). Methods: Four strains of Bifidobacterium and Lactobacillus were used to test the performance of different doses of MUP-MRS. Five Bifidobacterium lactis strains were counted in the commercial samples of Bifidobacterium lactis. The bifidobacteria were observed at different culture time growing situation. Results: The growth rates of bifidobacteria ranged from 0.98 to 1.19 and the Bifidobacterium bifidum did not grow when L i-MUP was 0.5 mg ~ 1.0 mg / 100 ml. L i-MUP was greater than Bifidobacteria did not grow at 2.0 mg / 100 ml. In 5 samples, Bifidobacterium lactis counted 1.0 × 106 ~ 3.9 × 108CFU / ml with L i-MUP of 0.5 mg ~ 0.75 mg / 100 ml and grew well; non-target lactic acid bacteria were completely inhibited (except Lactobacillus plantarum) . Bifidobacterium lactis did not grow at L i-MUP at 1.0 mg / 100 ml. Bifidobacterium cultured 48 h ± 2 h, colonies less; cultured 72 h ± 2 h, the formation of easily counted colonies. CONCLUSION: When counting Bifidobacterium with MUP-MRS agar, the dosage of L i-MUP is 0.5 mg ~ 0.75 mg / 100 ml, and the culture time is 72 h ± 2 h.