thiobacillus vs eubacterium

thiobacillus and eubacterium both are nouns.

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

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

thiobacillus: small rod-shaped bacteria living in sewage or soil and oxidizing sulfur
eubacterium: a large group of bacteria having rigid cell walls; motile types have flagella

Other hypernyms of thiobacillus include eubacteria, true bacteria.

thiobacillus (noun)	eubacterium (noun)
small rod-shaped bacteria living in sewage or soil and oxidizing sulfur	a large group of bacteria having rigid cell walls; motile types have flagella