摘要
在MRS平板上,采用琼脂扩散法测定了Nisin对Lactobacillus acidophilus la-5和Bifidobacterium bifidum Bb-12生长的抑制作用。当Nisin浓度≥50ug/ml时,对Lactobacillus acidophilus la-5表现出强烈的抑制作用,而Bifidobacterium bifidum Bb-12则几乎不生长,即使Nisin的浓度仅为25ug/ml;当L.acidophilus la-5和B.bifidum Bb-12单独或两者共同在37℃发酵10％(w/w)还原脱脂奶时,脱脂奶中添加的50ug/ml Nisin对B.bifidum Bb-12表现出杀菌作用,而对L.acidophilus La-5则为抑菌作用。当延长培养时间后,L.acidophilus La-5的存在可以降低Nisin对B.bifidum Bb-12的致死作用。
The growth-inhibitory effects of nisin on Lacto bifidum Bb-12 were measured on MRS by agar diffusic exceeded 50ug/ml, the growth of Lactobacillus acidophi nearly no growth occurred to B. bifidum Bb-12 even i ug/ml. When L. acidophilus La-5 and B. bifidum Bb-skim milk with nisin added at the concentration of 50ug mixture starters, the drop of the pH of the milk was gn without nisin. It was demonstrated that nisin added in th 108℃, 2 minutes, could inhibit strongly the growth oillus acidophilus La-5 and Bifidobacterium method. When the concentration of nisinLa-5 was strongly inhibited. Meanwhile, sue concentration of nisin was as low as 25were inoculated in 10%(w/w) recombined 1, at the level of 108 cfu/ml as single or y delayed compared with the control group milk, which can resist a heat treatment of L acidophilus La-5 and have a distinct bactericidal effect on B. bifidum Bb-12. When B. bifidum Bb-12 was incubated with L. acidophilus La-5 in the milk for an elongated time, the bactericidal activity of nisin on B. bifidum Bb-12 was partially alleviated by the growth of L. acidophilus La-5.
出处
《乳业科学与技术》
2002年第2期1-6,共6页
JOURNAL OF DAIRY SCIENCE AND TECHNOLOGY
