Marine macroalgae are the habitat of epiphytic bacteria and provide several conditions for a beneficial biological interaction to thrive. Although is one of the most abundant epiphytic genera, genomic information on marine macroalgae-associated species remains scarce. In this study, we further investigated our previously published genome of the epiphytic strain 19_A to find features that could be translated to potential metabolites produced by this microorganism, as well as genes that play a role in its interaction with its macroalgal host. To achieve this goal, we performed a pan-genome analysis of sp. and a codon bias assessment, including the genome of the strain 19_A and 29 complete genome sequences of closely related strains isolated from soil, marine environments, plants, extreme environments, air, and food. This genomic analysis revealed that 19_A possessed unique genes encoding proteins involved in horizontal gene transfer, DNA repair, transcriptional regulation, and bacteriocin biosynthesis. In this comparative analysis, codon bias was not associated with the habitat of the strains studied. Some accessory genes were identified in the 19_A genome that could be related to its epiphytic lifestyle, as well as gene clusters for the biosynthesis of a sporulation-killing factor and a bacteriocin, showing their potential as a source of antimicrobial peptides. Our results provide a comprehensive view of the 19_A genome to understand its adaptation to the marine environment and its potential as a producer of bioactive compounds.