Bacterivores are free-living, generally
heterotrophic organisms, exclusively
microscopic, which obtain energy and nutrients primarily or entirely from the consumption of
bacteria. Many species of
amoeba are bacterivores, as well as other types of
protozoans. In common, all species of bacteria will be prey, but spores of some species, such as
Clostridium perfringens, will never be prey, because of their cellular attributes.