Expanding the Diversity of Myoviridae Phages Infecting Lactobacillus Plantarum - A Novel Lineage of Lactobacillus Phages Comprising Five New Members

Lactobacillus plantarum is a bacterium with promising applications to the food industry and agriculture and probiotic properties. So far, bacteriophages of this bacterium have been moderately addressed. We examined the morphology and diversity of five new L. plantarum phages via transmission electron microscopy, whole genome shotgun sequencing and in silico protein predictions. Moreover, we looked into their phylogeny and their potential genomic similarities to other complete phage genome records through extensive nucleotide and protein comparisons. The five phages share a high degree of similarity among them and belong to the family Myoviridae. They have a long genome of 137.973-141.344 bp, a G/C content of 36,3-36,6% that is quite distinct from their host’s, and, surprisingly, seven to 15 tRNAs. Only an average 35/174 of their predicted genes were assigned a function. Overall, the comparative analyses unraveled considerable genetic diversity for our five L. plantarum phages. Hence, the new genus “Semelevirus” was proposed, which comprises exclusively the five phages. This novel lineage of Lactobacillus phages provides further insight into the genetic heterogeneity of phages infecting Lactobacillus sp. Our results on Lactobacillus phages have a potential value for the development of anti-phage strategies as well as for the manipulation of L. plantarum fermentations.