Obligate v. t. : To bring or place under obligation, moral or legal; to hold by a constraining motive.

Obligate v. t. : To bind or firmly hold to an act; to compel; to constrain; to bind to any act of duty or courtesy by a formal pledge.

Example:
What is the difference between a normal Obligate thermophile and a thermophile?

Taxonomy
Obligate, organism, free encyclopedia, dissolved oxygen, antonym, facultative, search, free dictionary, adjective, biology, phrases, Obligate parasite, parasite, Obligate intracellular parasite, parasitic, microorganism, host cell, presence.

Defination from the web:
Obligate parasite, a parasite that cannot survive without its host. Obligate intracellular parasite, a parasitic microorganism that ... Obligate air-breather, a complex organism which obtains required oxygen directly from the atmosphere through respiration rather than extracting ...