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auxotroph Syllabification: aux·o·troph
Pronunciation: /ˈôksəˌträf/ /-ˌtrōf/

Definition of auxotroph in English:


A mutant organism (typically a bacterium or fungus) that requires a particular additional nutrient that the normal strain does not.
Example sentences
  • 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.
  • 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.
  • Both of these mutants seem to be thiamin auxotrophs because they appeared normal when grown on media supplemented with 0.1 mM thiamin.


Pronunciation: /ˌôksəˈträfik/ /-ˈtrō-/
Example sentences
  • Previous work on Drosophila de novo purine synthesis genes showed that 4 mg/ml RNA supplementation can rescue the phenotype of auxotrophic mutants fed a defined medium.
  • Linear relationships have been found between increasing levels of the supplied amino acid and the bioluminescence emission of the auxotrophic mutant of E. coli carrying the lux system.
  • The data indicate that the mutations complement with respect to the auxotrophic phenotype when grown on Sang's medium.


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

Definition of auxotroph in:
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