Assessment of Species Diversity through Pan-Genome Analysis with Newly Isolated sp. 3-20A1M.

species are extensively studied marine bacteria that produce various carotenoids. Due to their photoheterotrophic ability, it has been suggested that they play a crucial role in marine ecosystems. It is essential to identify the genome sequence and the genes of the species to predict their role in the marine ecosystem. In this study, we report the complete genome sequence of the marine bacterium sp. 3-20A1M. The genome size was 3.1 Mbp and its GC content was 64.8%. In total, 2998 genetic features were annotated, of which 2882 were annotated as functional coding genes. Using the genetic information of sp. 3-20A1M, we performed pangenome analysis with other species. This revealed highly conserved secondary metabolite biosynthesis-related COG functions across species. Through subsequent secondary metabolite biosynthetic gene cluster prediction and KEGG analysis, the carotenoid biosynthetic pathway was proven conserved in all species, except for the spheroidene and spirilloxanthin pathways, which are only found in photosynthetic species. The presence of virulence genes, especially the plant-algae cell wall degrading genes, revealed that sp. 3-20A1M is a potential marine plant-algae scavenger.