食品科学 ›› 2019, Vol. 40 ›› Issue (10): 50-56.doi: 10.7506/spkx1002-6630-20180619-359

• 生物工程 • 上一篇    下一篇

phoP调节子对阪崎克罗诺肠杆菌环境耐受力的影响

周亚琴,李梦云,夏效东*   

  1. 西北农林科技大学食品科学与工程学院,陕西 杨凌 712100
  • 出版日期:2019-05-25 发布日期:2019-05-31
  • 基金资助:
    国家自然科学基金面上项目(31772084);中央高校基本科研业务费专项(2452017146;2452017228)

Role of phoP Regulon in Environmental Stress Tolerance in Cronobacter sakazakii

ZHOU Yaqin, LI Mengyun, XIA Xiaodong*   

  1. College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China
  • Online:2019-05-25 Published:2019-05-31

摘要: 为研究克阪崎罗诺肠杆菌中phoP基因与环境耐受力的关系,采用Red同源重组方法构建阪崎克罗诺肠杆菌的phoP基因缺失菌株,并从生长曲线、酸碱耐受、温度耐受等方面,研究phoP基因缺失前后阪崎克罗诺肠杆菌环境耐受力的变化。结果表明:phoP基因缺失菌株的生长速度明显延缓,该基因的缺失减弱了菌对外界酸碱和高温的耐受性,并缩短了热致死时间;phoP基因缺失菌株抵御胆盐环境的能力亦有所下降,与野生型菌株相比,它在4%、8%、12%胆盐溶液环境中的存活率分别降低了19.93%(P<0.05)、40.73%(P<0.01)和45.84%(P<0.01)。此外phoP基因缺失菌株对渗透压的耐受力与野生株相比也显著降低(P<0.05)。综合以上结果表明,phoP基因有助于阪崎克罗诺肠杆菌应对外界环境刺激。

关键词: phoP基因, 阪崎克罗诺肠杆菌, 环境耐受

Abstract: The aim of this study was to investigate the effect of the phoP regulon on environmental stress tolerance in Cronobacter sakazakii. A phoP-deleted strain of C. sakazakii was constructed by using the Red homologous recombination method, and then the growth curve and stress tolerance of the phoP-deleted strain were examined. The results showed that the phoP-defective strain showed delayed growth and weaker tolerance to external acid-base and heat stress. Meanwhile, it exhibited shortened time of death from heat treatment. phoP rendered C. sakazakii tolerant to bile salt environment, and its deletion resulted in a reduction in survival rate of 19.93% (P < 0.05), 40.73% (P < 0.01) and 45.84% (P < 0.01) in 4%, 8% and 12% bile salt solutions, respectively. The tolerance to osmotic pressure of the phoP gene-deficient strain was also significantly lower than that of the wild-type strain (P < 0.05). In conclusion, phoP enables C. sakazakii to respond to environmental stimuli.

Key words: phoP, Cronobacter sakazakii, environmental tolerance

中图分类号: