caulobacter caulobacter caulobacter is a genus of gram-negative bacteria in the class alphaproteobacteria. its best-known member is caulobacter crescentus, an organism ubiquitous in freshwater lakes and rivers; many members of the genus are specialized to oligotrophic environments. caulobacter caulobacter crescentus scientific classification domain: bacteria phylum: pseudomonadota class: alphaproteobacteria order: caulobacterales family: caulobacteraceae genus: caulobacterpoindexter 1964 species c. crescentus c. daechungensis c. flavus c. fusiformis c. ginsengisoli c. heinricii c. hibisci c. mirabilis c. mirare c. profundis c. radicis c. rhizosphaerae c. segnis c. zeae interactions with other organisms pathogenicity although caulobacter is not commonly appreciated as a cause of human diseases, caulobacter isolates have been implicated in a number of cases of recurrent peritonitis in peritoneal dialysis patients. one study has identified the species c. crescentus and c. mirare as the cause of a disease of the moth galleria mellonella; the absence of identified distinct virulence factors in c. mirare may suggest that other caulobacter species have pathogenic potential.