nitrosobacteria vs eubacterium

nitrosobacteria and eubacterium both are nouns.

Word	Noun	Adjective	Verb	Adverb
nitrosobacteria	Yes	No	No	No
eubacterium	Yes	No	No	No

As nouns, eubacterium is a hypernym of nitrosobacteria; that is, eubacterium is a word with a broader meaning than nitrosobacteria:

nitrosobacteria: soil bacteria that oxidize ammonia to nitrites
eubacterium: a large group of bacteria having rigid cell walls; motile types have flagella

Other hypernyms of nitrosobacteria include eubacteria, true bacteria.

nitrosobacteria (noun)	eubacterium (noun)
soil bacteria that oxidize ammonia to nitrites	a large group of bacteria having rigid cell walls; motile types have flagella