Initial efforts to sequence the genome of the marine diatom Skeletonema marinoi were hampered by the presence of genetic material from bacteria, and there was sufficient material from some of these bacteria to enable the assembly of full chromosomes. Here, we report the genome of strain SMS9, one such bacterial species identified in a non-axenic culture of S. marinoi strain ST54. Its 5,482,391 bp circular chromosome contains 4,641 CDSs, and has a G+C content of 35.6%. Based on 16S rRNA comparison, phylotaxonomic analysis, and the genome similarity metrics dDDH and OrthoANI, we place this strain in the genus Kordia, and to the best of our knowledge, this is the first Kordia species to be initially described from European waters. As attempts to culture this strain have failed, however, the specifics of its relationship with S. marinoi are still uncertain.
Keywords: Diatom; Kordia; Marine sediment; Microbiome; Skeletonema; Whole Genome Sequencing.