Data_Sheet_1_Screening of Polyvalent Phage-Resistant Escherichia coli Strains Based on Phage Receptor Analysis.pdf

Bacteria-based biotechnology processes are constantly under threat from bacteriophage infection, with phage contamination being a non-neglectable problem for microbial fermentation. The essence of this problem is the complex co-evolutionary relationship between phages and bacteria. The development of phage control strategies requires further knowledge about phage-host interactions, while the widespread use of Escherichia coli strain BL21 (DE3) in biotechnological processes makes the study of phage receptors in this strain particularly important. Here, eight phages infecting E. coli BL21 (DE3) via different receptors were isolated and subsequently identified as members of the genera T4virus, Js98virus, Felix01virus, T1virus, and Rtpvirus. Phage receptors were identified by whole-genome sequencing of phage-resistant E. coli strains and sequence comparison with wild-type BL21 (DE3). Results showed that the receptors for the isolated phages, designated vB_EcoS_IME18, vB_EcoS_IME253, vB_EcoM_IME281, vB_EcoM_IME338, vB_EcoM_IME339, vB_EcoM_IME340, vB_EcoM_IME341, and vB_EcoS_IME347 were FhuA, FepA, OmpF, lipopolysaccharide, Tsx, OmpA, FadL, and YncD, respectively. A polyvalent phage-resistant BL21 (DE3)-derived strain, designated PR8, was then identified by screening with a phage cocktail consisting of the eight phages. Strain PR8 is resistant to 23 of 32 tested phages including Myoviridae and Siphoviridae phages. Strains BL21 (DE3) and PR8 showed similar expression levels of enhanced green fluorescent protein. Thus, PR8 may be used as a phage resistant strain for fermentation processes. The findings of this study contribute significantly to our knowledge of phage-host interactions and may help prevent phage contamination in fermentation.

基于细菌的生物技术工艺始终面临噬菌体感染的威胁，噬菌体污染已成为微生物发酵领域不可忽视的问题。该问题的本质在于噬菌体与细菌之间复杂的共进化关系。噬菌体防控策略的开发有赖于对噬菌体-宿主互作机制的深入解析，而大肠杆菌（Escherichia coli）BL21 (DE3)菌株在生物技术工艺中的广泛应用，使得针对该菌株的噬菌体受体研究显得尤为重要。本研究分离得到8株可通过不同受体侵染大肠杆菌BL21 (DE3)的噬菌体，经鉴定分别属于T4噬菌体属（T4virus）、Js98噬菌体属（Js98virus）、Felix01噬菌体属（Felix01virus）、T1噬菌体属（T1virus）以及Rtp噬菌体属（Rtpvirus）。通过对噬菌体抗性大肠杆菌菌株进行全基因组测序，并与野生型BL21 (DE3)的基因组序列进行比对，鉴定出了各噬菌体对应的受体。研究结果显示，本次分离得到的8株噬菌体分别命名为vB_EcoS_IME18、vB_EcoS_IME253、vB_EcoM_IME281、vB_EcoM_IME338、vB_EcoM_IME339、vB_EcoM_IME340、vB_EcoM_IME341以及vB_EcoS_IME347，其对应的受体依次为FhuA、FepA、OmpF、脂多糖（lipopolysaccharide）、Tsx、OmpA、FadL以及YncD。随后，通过由这8株噬菌体组成的噬菌体混合液进行筛选，获得了一株多价噬菌体抗性的BL21 (DE3)衍生菌株，命名为PR8。PR8菌株对32株供试噬菌体中的23株具有抗性，其中涵盖肌尾噬菌体科（Myoviridae）与长尾噬菌体科（Siphoviridae）的噬菌体。BL21 (DE3)与PR8菌株的增强型绿色荧光蛋白（enhanced green fluorescent protein）表达水平无显著差异。因此，PR8菌株可作为噬菌体抗性菌株应用于发酵工艺中。本研究的发现显著深化了我们对噬菌体-宿主互作机制的认知，同时可为发酵过程中的噬菌体污染防控提供理论支撑。