azospirillum halopraeferens azospirillum halopraeferens azospirillum halopraeferens is a species of nitrogen-fixing bacteria associated with the roots of diplachne fusca and black mangrove. it is microaerophilic and its type strain is au 4 (= lmg 7108 =dsm 3675). azospirillum halopraeferens scientific classification domain: bacteria phylum: pseudomonadota class: alphaproteobacteria order: rhodospirillales family: azospirillaceae genus: azospirillum species: azospirillum halopraeferensreinhold et al., 1987