Our previous study on a model microbial community originating from an artisanal cheese fermentation starter revealed that bacteriophages not only co-exist with bacteria but also are highly abundant. Here we describe the genomic content of phage particles released by 6 different strains in the starter culture. The identified prophages belong to three different subgroups of the Siphoviridae P335 phage group. Remarkably, most analysed prophages show disruptions in different tail encoding genes, explaining the common tailless phenotype. Furthermore, a number of potentially beneficial features for the host carried by prophages were identified. The prophages carry up to 3 different phage defence systems per genome that are potentially functional in protecting the host from foreign phage infection. We suggest that the presumably defective prophages are a result of bacteria-phage coevolution and could convey advantages to host bacteria.