alterococcus alterococcus alterococcus is a genus of bacteria from the family of opitutaceae with one species alterococcus agarolyticus. alterococcus scientific classification domain: bacteria phylum: verrucomicrobiota class: opitutae order: opitutales family: opitutaceae genus: alterococcusshieh and jean 1999 type species alterococcus agarolyticus species a. agarolyticus