phreatobacter cathodiphilus phreatobacter cathodiphilus phreatobacter cathodiphilus is a gram-negative, aerobic, non-spore-forming and motile bacterium from the genus of phreatobacter. phreatobacter cathodiphilus scientific classification domain: bacteria phylum: pseudomonadota class: alphaproteobacteria order: hyphomicrobiales family: phreatobacteraceae genus: phreatobacter species: p. cathodiphilus binomial name phreatobacter cathodiphiluskim et al. 2018 type strain s-12