methylobacterium radiotolerans methylobacterium radiotolerans methylobacterium radiotolerans is a radiation-tolerating gram-negative bacterium. it has been shown that it can use lanthanide as a cofactor to increase its methanol dehydrogenase activity methylobacterium radiotolerans scientific classification domain: bacteria phylum: pseudomonadota class: alphaproteobacteria order: hyphomicrobiales family: methylobacteriaceae genus: methylobacterium binomial name methylobacterium radiotoleranscorrig. (ito and iizuka 1971) green and bousfield 1983 synonyms pseudomonas radiora ito and iizuka 1971 (approved lists 1980) methylobacterium radiora (ito and iizuka 1971) green and bousfield 1983