lactobacillus vs eubacterium

lactobacillus and eubacterium both are nouns.

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

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

lactobacillus: a Gram-positive rod-shaped bacterium that produces lactic acid (especially in milk)
eubacterium: a large group of bacteria having rigid cell walls; motile types have flagella

Other hypernyms of lactobacillus include eubacteria, true bacteria.

lactobacillus (noun)	eubacterium (noun)
a Gram-positive rod-shaped bacterium that produces lactic acid (especially in milk)	a large group of bacteria having rigid cell walls; motile types have flagella