Đặc điểm sinh học của chủng vi khuẩn lactic sinh tổng hợp Bacteriocin
Tóm tắt
A total 40 samples of raw cow's milk taken from different regions as Phu Dong, Ba Vi, Xuan Mai, Hoai Due - Ha Noi, isolated about 7.33 x 10^ lactic acid bacteria strains. 32 strains which showed strong activities against L. plantarum JCM 1149 were selected for the research.These strains share the same clone shape and their cell forms are quite identical (about 92,75% of cocci). Among them, the strains PD14; PD2.9; BV20 were considered better activities of producing bacteriocin and wwider antibacterial spectrum. Reaction to temperature of PD14; PD2.9; BV20 were determined by growth rate (OD) and bacteriocin biosynthesis activities indicated that they belong to mesophile, the optimal growth temperature is 30°C. Besides, these strains are resistant to chloramphenicol and streptomycin at high concentrations. A plasmid has
been discovered in these 3 strains. However, the relation between the antibiotic resistance and the plasmid is a problem for further study.