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tr.v. ob·li·gat·ed, ob·li·gat·ing, ob·li·gates
1. To compel or constrain by a social, legal, or moral requirement. See Synonyms at force.
2. To cause to be grateful or indebted; oblige: We will always be obligated to you for your kindness.
3. To commit (money, for example) in order to fulfill an obligation.
adj. (-gĭt, -gāt′)
Able to exist or survive only in a particular environment or by assuming a particular role: an obligate parasite; an obligate anaerobe.
n. (-gĭt, -gāt′)
An obligate organism.

[Latin obligāre, obligāt-; see oblige.]

ob′li·ga·ble (-gə-bəl) adj.
ob′li·gate·ly adv.
ob′li·ga′tor n.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(Biology) biology in an obligate or necessary manner
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
References in periodicals archive ?
Although clonal reproduction is expected to be reproductively advantageous (Maynard-Smith 1978; Bell 1982), obligately asexual organisms are short-lived on geologic time scales and have been regarded as evolutionary dead ends (Bell 1982; Lorenzo-Carballa et al.
The genome of the obligately intracellular bacterium Ehrlichia canis reveals themes of complex membrane structure and immune evasion strategies.
nov., an obligately anaerobic species from wastewater of a paper mill.
Obligately intracellular Rickettsia spp., typically transmitted by ticks, cause a multitude of mild to severe rickettsial diseases in humans and other animals.
Under the obligately anaerobic conditions, QMA with four methyl moieties serves as an excellent substrate for methane production through methanogenesis pathways.
acidophilus is an obligately homofermentative bacteria (produces lactic acid as main metabolic product) while L.
They are obligately dependent on the fungi they grow, though displaying great variation in their ecology (Mehdiabadi & Schultz 2010).
Given that tau hyperphosphorylation precedes aggregation, and tau aggregates are obligately phosphorylated in AD brain, phosphorylation has been suggested as a primary trigger for tau aggregation.
When a hypolimnion remains anoxic, obligately anaerobic prokaryotic populations, including Archaeal methanogens, presumably increase, but a lake that never has an oxygenated hypolimnion due to salt-induced stratification likely produces more methane because conditions that favor methanogen growth are persistent.
Individual variation in feeding habitat use by adult female green sea turtles (Chelonia mydas): are they obligately neritic herbivores?