Where does “microaerotolerant” come from?

microaerotolerant (English) comes from English aerotolerant, from English aero, from English aero-, from Ancient Greek ἀέρος, from Ancient Greek ἀήρ, from Ancient Greek auhḗr.

microaerotolerant (English): Able to tolerate only a very low amount of air (oxygen)

Definitions

Able to tolerate only a very low amount of air (oxygen)

Ancestry of “microaerotolerant”, step by step

microaerotolerant traces back through two separate lines of ancestry.

via English aerotolerant

Step	Language	Word	Meaning
1	English	aerotolerant	Able to tolerate the presence of air
2	English	aero	Of or pertaining to aviation; Aerodynamic; having...
3	English	aero-	air or aircraft
4	Ancient Greek	ἀέρος	genitive singular of ἀήρ; air
5	Ancient Greek	ἀήρ	mist; air; wind
6	Ancient Greek	auhḗr	—

via English micro

Step	Language	Word	Meaning
1	English	micro	Small, relatively small; short form of...
2	Ancient Greek	μικρός	little, small
3	Proto-Indo-European	mēy-	soft, tender, dear

Every word from Ancient Greek auhḗr →Every word from Ancient Greek ἀήρ →Every word from English aero- →