Journal of Microbiology

Journal Article

Tn5 Transposon-based Mutagenesis for Engineering Phage-resistant Strains of Escherichia coli BL21 (DE3): Yinfeng Wang , Guanhua Xuan , Houqi Ning , Jiuna Kong , Hong Lin , Jingxue Wang; J. Microbiol. 2023;61(5):559-569. Published online May 22, 2023; DOI: https://doi.org/10.1007/s12275-023-00048-2

Abstract: Escherichia coli is a preferred strain for recombinant protein production, however, it is often plagued by phage infection during experimental studies and industrial fermentation. While the existing methods of obtaining phage-resistant strains by natural mutation are not efficient enough and time-consuming. Herein, a high-throughput method by combining Tn5 transposon mutation and phage screening was used to produce Escherichia coli BL21 (DE3) phage-resistant strains. Mutant strains PR281-7, PR338-8, PR339-3, PR340-8, and PR347-9 were obtained, and they could effectively resist phage infection. Meanwhile, they had good growth ability, did not contain pseudolysogenic strains, and were controllable. The resultant phage-resistant strains maintained the capabilities of producing recombinant proteins since no difference in mCherry red fluorescent protein expression was found in phage-resistant strains. Comparative genomics showed that PR281-7, PR338-8, PR339-3, and PR340-8 mutated in ecpE, nohD, nrdR, and livM genes, respectively. In this work, a strategy was successfully developed to obtain phage-resistant strains with excellent protein expression characteristics by Tn5 transposon mutation. This study provides a new reference to solve the phage contamination problem.

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