食品科学 ›› 2019, Vol. 40 ›› Issue (18): 130-136.doi: 10.7506/spkx1002-6630-20180828-304

• 生物工程 • 上一篇    下一篇

1 株裂解性短尾沙门氏菌噬菌体T139的生物学特性及其对牛奶和牛肉的抑菌作用

聂若男,李晚宁,杨其乐,王小红,王佳   

  1. (华中农业大学食品科学技术学院,湖北?武汉 430070)
  • 出版日期:2019-09-25 发布日期:2019-09-23
  • 基金资助:
    “十三五”国家重点研发计划重点专项(2017YFC1600100);国家自然科学基金面上项目(31772054)

Biological Characteristics of a Lytic Short-Tailed Salmonella Phage T139 and Its Antibacterial Effect in Milk and Ground Beef

NIE Ruonan, LI Wanning, YANG Qile, WANG Xiaohong, WANG Jia   

  1. (College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China)
  • Online:2019-09-25 Published:2019-09-23

摘要: 采用双层平板的方法以鼠伤寒沙门氏菌(ATCC 13311)为宿主菌,从污水中分离得到1 株裂解性噬菌体,命名为T139,研究其生物学特性及其在牛奶和牛肉样品中的抑菌作用。结果表明:噬菌体T139的噬菌斑透亮清晰;能裂解宿主菌及其他沙门氏菌,为宽宿主谱;电镜观察噬菌体T139属于短尾噬菌体科,头部直径为(43±1)nm,尾部长(11±0.6)nm;最佳感染复数(multiplicity of infection,MOI)为0.001;最佳吸附速率为66%;一步生长曲线结果显示潜伏期为5?min,爆发期为60?min,平均裂解量为54.54?PFU/cell;在30~50?℃和pH?4~12条件下稳定且对体外培养的鼠伤寒沙门氏菌有良好的裂解效果。噬菌体T139对牛奶中鼠伤寒沙门氏菌的抑菌效果为:在4?℃无显著效果,在25?℃条件下MOI=10和MOI=100时抑菌效果极其显著,宿主菌数量分别下降4.32(lg(CFU/mL))和4.27(lg(CFU/mL));噬菌体T139对牛肉中鼠伤寒沙门氏菌的抑菌效果为:在4?℃条件下,MOI=10时无显著效果,在MOI=100时宿主菌数量下降0.66(lg(CFU/mL)),在25?℃条件下MOI=10和MOI=100时宿主菌数量分别下降了0.77(lg(CFU/mL))和1.16(lg(CFU/mL)),表明噬菌体T139对牛奶和牛肉中鼠伤寒沙门氏菌有良好抑制作用。

关键词: 鼠伤寒沙门氏菌, 裂解性噬菌体, 生物学特性, 抑菌效果

Abstract: A double-layer plate method was used to isolate a virulent phage named T139 from sewage using Salmonella typhimurium (ATCC 13311) as the host strain, and the biological characteristics and antibacterial activity of phage T139 in milk and beef samples were studied. The results showed that phage T139 formed clear plaques; it could lyse its host bacterium and other Salmonella strains with a broad host spectrum. Transmission electron microscopic (TEM) observation showed that phage T139 belonged to the Podoviridae family with a head diameter of (43 ± 1) nm and a tail length of (11 ± 0.6) nm. The optimal multiplicity?of?infection (MOI) of this phage was 0.001, and the optimal adsorption rate was 66%. The one-step growth curve showed that the latent period was 5 min, the burst period was 60 min, and the average lysis amount was 54.54 PFU/cell. The phage was stable within 30–50 ℃ and pH 4–12. It had a good lytic effect on S. typhimurium cultured in vitro. The antibacterial effect of phage T139 on S. typhimurium in milk was not significant at 4 ℃, and the number of host cells decreased by 4.32 and 4.27 (lg (CFU/mL)) at MOI = 10 and 100 at 25 ℃, respectively. Similarly, it had no significant effect on S. typhimurium in beef at 4 ℃, MOI = 10, whereas at MOI = 100, the number of host cells decreased by 0.66 (lg (CFU/mL)). At 25 ℃, MOI = 10 and 100, the number of host cells decreased by 0.77 and 1.16 (lg (CFU/mL)), respectively. It was shown that phage T139 could effectively inactivate S. typhimurium in milk and beef.

Key words: Salmonella typhimurium, lytic phage, biological characteristics, antibacterial effect

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