mycobacterium vs eubacteria

mycobacterium and eubacteria both are nouns.

Word	Noun	Adjective	Verb	Adverb
mycobacterium	Yes	No	No	No
eubacteria	Yes	No	No	No

As nouns, eubacteria is a hypernym of mycobacterium; that is, eubacteria is a word with a broader meaning than mycobacterium:

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

Other hypernyms of mycobacterium include eubacterium, true bacteria.

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