sphingobacterium caeni sphingobacterium caeni sphingobacterium caeni is a gram-negative, non-spore-forming, rod-shaped and non-motile bacterium from the genus of sphingobacterium which has been isolated from activated sludge. sphingobacterium caeni scientific classification domain: bacteria phylum: bacteroidota class: sphingobacteriia order: sphingobacteriales family: sphingobacteriaceae genus: sphingobacterium species: s. caeni binomial name sphingobacterium caenisun et al. 2013 type strain cctcc ab 2012020, dc-8, kacc 16850