China Animal Husbandry and Veterinary Medicine ›› 2021, Vol. 48 ›› Issue (6): 2140-2149.doi: 10.16431/j.cnki.1671-7236.2021.06.027

• Preventive Veterinary Medicine • Previous Articles     Next Articles

Isolation and Biological Characterization of Lactobacillus Phage

QIN Songyue, ZHAO Li, DI Yaxin, YU Xiaoli, WANG Li, TANG Lijie, XU Yigang, ZHOU Han, JIANG Yanping, CUI Wen, LI Yijing, QIAO Xinyuan   

  1. Laboratory for Animal Disease Prevention and Control Technology and Preparation, College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China
  • Received:2020-12-21 Online:2021-06-20 Published:2021-06-18

Abstract: In order to understand the biological characteristics of Lactobacillus phage,and provide experimental data and reference for the prevention and control of phage pollution during fermentation production,in this study,Lactobacillus phages were isolated from dairy products and kimchi samples by spot test and double-layer agar plate method,L.casei ATCC 393,L.pentosus KLDS 1.0413 and L.brevis ATCC 367 were used as indicator bacteria.The morphology of the phage was observed by transmission electron microscopy,and the packaging mechanism of the phage was analyzed by the restriction enzyme activity of the phage genome,the host range and one-step growth curve were measured,the structural proteins of the phage were analyzed by SDS-PAGE to analyse the biological characteristics of the obtained phage.The results showed that three virulent Lactobacillus phages were isolated and named as Lc,Lpen and Lbre,respectively.The results of electron microscopy showed that phage Lc and Lpen were consisted of polyhedral heads and non-contractive tails,while phage Lbre was consisted of polyhedral heads and contractile tails.According to morphology analysis,Lc and Lpen belonged to the Siphoviridae family,B1 category,and Lbre belonged to the Myoviridae family,A1 category.The genomes of phages were extracted and subjected to restriction endonuclease.The results of nucleic acid electrophoresis showed that the genomes of phage Lc and Lpen both had heterogeneous blunt ends,and the packaging mechanism was full-head packaging,namely pac-type,while Lbre contained stickiness end,the packaging mechanism belonged to cos-type.The phage Lc and Lbre were host-specific,and the host spectrum of phage Lpen was broader.The one-step growth curve showed that the latent period of Lc,Lpen and Lbre were 60,45 and 150 min respectively,the burst period were 45,90 and 105 min respectively,and the burst size were 47,24 and 30 PFU/cell respectively.SDS-PAGE testing indicated that phage Lc had 7 structural proteins,while phage Lpen,Lbre had 5 structural proteins,their protein molecular weight were about 50,55 and 50 ku,respectively.In conclusion,three virulent Lactobacillus phages were isolated and their biological characteristics were indentified,which provided important experimental data and theoretical basis for understanding the prevention and control of virulent Lactobacillus phages contamination.

Key words: Lactobacillus; phage; biological characteristics

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