Shewanella violacea DSS12 (S. violacea) is a gram-negative bacterium located in marine sediment in the Ryukyu Trench at a depth of 5,110m. The first description of this organism was published in 1998 by Japanese microbiologists Yuichi Nogi, Chiaki Kato, and Koki Horikoshi, who named the species after its violet appearance when it is grown on Marine Agar 2216 Plates.