Genomic and biological characteristics of a novel phage induced from Limosilactobacillus fermentum

Bacteriophage infection of starter cultures remains a major threat to the food fermentation industry. To date, adequate information regarding the genome and characteristics of the Limosilactobacillus fermentum (L. fermentum) phage is lacking. The phage LFP01 was obtained by inducing L. fermentum IMAU32646 with mitomycin-C. The results showed that this phage contained a linear double-stranded DNA genome spanning 40,562 bp with a GC content of 46.25%. It comprises 54 coding sequences, which are grouped into three potential functional modules: DNA replication, cell lysogeny/lysis, and virion morphogenesis. Taxonomic analysis further confirmed that this phage belonged to a novel virus genus within the Caudoviricetes class. The optimal multiplicity of infection was 0.1, the latent period was 45 min, and the burst size was 158 +/- 2.65 PFU/cell. This phage exhibited good environmental tolerance at 0-42 C-degrees and a pH of 4-11. High temperature (50 C-degrees) and strongly acidic (pH 2-3) conditions significantly influenced the adsorption capacity of the phage, but divalent cations and chloramphenicol had no similar effect. The findings of this study could enrich the database of phages and broaden the understanding of phage diversity.