halobacteria vs halobacterium

halobacteria and halobacterium both are nouns.

Word	Noun	Adjective	Verb	Adverb
halobacteria	Yes	No	No	No
halobacterium	Yes	No	No	No

As nouns, halobacteria and halobacterium are synonyms defined as:

halobacteria and halobacterium: halophiles in saline environments such as the Dead Sea or salt flats

Other synonyms of halobacteria include halobacter.

halobacteria (noun)	halobacterium (noun)
halophiles in saline environments such as the Dead Sea or salt flats	halophiles in saline environments such as the Dead Sea or salt flats