aquaspirillum fasciculus aquaspirillum fasciculus aquaspirillum fasciculus is a gram-negative freshwater rod in the genus aquaspirillum. aquaspirillum fasciculus scientific classification domain: bacteria phylum: pseudomonadota class: betaproteobacteria order: neisseriales family: neisseriaceae genus: aquaspirillum species: a. fasciculus binomial name aquaspirillum fasciculusstrength 1976 description the species lives in freshwater and propels itself through flagella.