mycobacteria vs eubacterium

mycobacteria and eubacterium both are nouns.

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

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

mycobacteria: rod-shaped bacteria some saprophytic or causing diseases
eubacterium: a large group of bacteria having rigid cell walls; motile types have flagella

Other hypernyms of mycobacteria include eubacteria, true bacteria.

mycobacteria (noun)	eubacterium (noun)
rod-shaped bacteria some saprophytic or causing diseases	a large group of bacteria having rigid cell walls; motile types have flagella