nioella ostreopsis nioella ostreopsis nioella ostreopsis is a gram-negative, short-rod-shaped, strictly aerobic and non-motile bacterium in the genus of nioella which has been isolated from the dinoflagellate ostreopsis lenticularis. nioella ostreopsis scientific classification domain: bacteria phylum: pseudomonadota class: alphaproteobacteria order: rhodobacterales family: rhodobacteraceae genus: nioella species: n. ostreopsis binomial name nioella ostreopsisyang et al. 2020 type strain z7-4