quadricoccus quadricoccus quadricoccus is a genus of gram-negative, oxidase-negative, catalase-positive, aerobic, non-spore-forming, non-motile bacteria from the family of rhodocyclaceae which belongs to the class of betaproteobacteria. so far there is only on species of this genus known (quadricoccus australiensis). quadricoccus scientific classification domain: bacteria phylum: pseudomonadota class: betaproteobacteria order: rhodocyclales family: rhodocyclaceae genus: quadricoccusmaszenan et al. 2002 species: quadricoccus australiensis type species quadricoccus australiensis