Lysogenic phenomena are commonly observed in Lactobacillus species, with phages released from lysogenic strains considered the primary source of Lactobacillus phages. This poses significant risks to the food industry. To enhance the understanding of Lactobacillus phages, a phage, LFP01, was induced from Limosilactobacillus fermentum (L. fermentum) using mitomycin C. The phage exhibited an icosahedral head and a non-contractile tail, and it was classified as a new genus within the Caudovirales class. The optimal multiplicity of infection (MOI) for this phage was 0.1. It demonstrated good environmental tolerance across a temperature range of 0–42°C and pH 4–11. Compared to temperature, ethanol, isopropyl alcohol, and sodium hypochlorite, 0.25% peracetic acid was able to inactivate the phage most rapidly, achieving complete inactivation within just 5 min. Phage LFP01 possesses a linear double-stranded DNA genome, including functional modules associated with DNA replication, lysogeny/lysis, and morphogenesis. Comprehensive genomic and transcriptomic analysis revealed that the genes of phage LFP01 are expressed in a time-dependent manner. The phage LFP01 affects every step of host macromolecular synthesis by utilizing the host's transcriptional, translational, and metabolic pathways. The phage coordinating the host’s gene expression through its own encoded genes to complete self-propagation. This study thoroughly characterized L. fermentum phage LFP01 and explored its functional genes. It provides a foundation for understanding the diversity of Lactobacillus phages, enriches phages database, and offers theoretical and data support for interpreting the mechanisms of phage-host interactions.

Wenxin Ma, a PhD candidate at the College of Food Science and Engineering, Inner Mongolia Agricultural University.  She has been dedicated to the research on Lactobacillus phage.  She has published one research paper as the first author and holds two authorized patents.