Several studiesshow that Aquaspirillum dispar and Microvirgula aerodenitrificans have a rDNA similarity of greater that 99%. It has been proposed that the name Aquaspirillum disparcease to be relevant because Microvirgula aerodenitrificans is the type species of Microvirgula. However, no officialaction has been made, so Aquaspirillum dispar is still relevant.