phreatobacter oligotrophus phreatobacter oligotrophus phreatobacter oligotrophus is a bacterium from the genus of phreatobacter which has been isolated from ultrapure water from a power plant in hungaria. phreatobacter oligotrophus scientific classification domain: bacteria phylum: pseudomonadota class: alphaproteobacteria order: hyphomicrobiales family: phreatobacteraceae genus: phreatobacter species: p. oligotrophus binomial name phreatobacter oligotrophustóth et al. 2014