Bacterium rhymes with:
delirium, miriam, myriam, aquarium, atrium, auditorium, barium, crematorium, delirium, deuterium, disequilibrium, emporium, equilibrium, herbarium, honorarium, merriam, miriam, moratorium, myriam, mysterium, opprobrium, planetarium, tellurium, thorium, yttrium
Bacterium sounds like:
backstrom, beckstrom, bostrom, buckthorn, bystrom