cryptobacterium cryptobacterium cryptobacterium is a genus of actinomycetota, in the family coriobacteriaceae. up to now there is only one species of this genus known (cryptobacterium curtum). cryptobacterium scientific classification domain: bacteria phylum: actinomycetota class: coriobacteriia order: eggerthellales family: eggerthellaceae genus: cryptobacteriumnakazawa et al. 1999 species cryptobacterium curtum