Definition of auxotroph in English:



  • A mutant organism (especially a bacterium or fungus) that requires a particular additional nutrient which the normal strain does not.

    • ‘Both of these mutants seem to be thiamin auxotrophs because they appeared normal when grown on media supplemented with 0.1 mM thiamin.’
    • ‘These mutations result in plants that are stunted, have dark green leaves and show defects in flower development and timing of flowering, but unlike GA auxotrophs these mutants are not rescued by GA application.’
    • ‘However, we observed that a fraction of survivors become uracil auxotrophs, because of repair events associated with more complex chromosomal rearrangements.’
    • ‘While the purpose of early mutant isolations was mostly focused on the identification of auxotrophs, many of these early strains have been subjected to heavy mutagenesis.’
    • ‘Previous experiments had indicated that leu2 auxotrophs had no selective advantage in rich medium.’


1950s: from Latin auxilium ‘help’ + Greek trophos ‘feeder’.