phyllobacterium trifolii phyllobacterium trifolii phyllobacterium trifolii is a root-nodulating bacteria that was first isolated from nodules in trifolium and lupinus species. its type strain is petp02t (=lmg 22712t =cect 7015t). phyllobacterium trifolii scientific classification domain: bacteria phylum: pseudomonadota class: alphaproteobacteria order: hyphomicrobiales family: phyllobacteriaceae genus: phyllobacterium species: p. trifolii binomial name phyllobacterium trifoliivalverde et al. 2005