Adjective
auxotrophic (comparative more auxotrophic, superlative most auxotrophic)
(biology) Describing a strain of organism that requires a specific metabolic substance that the parent organism was able to synthesize by itself
Instead, the use of auxotrophic bacterial strains (and function-replacement plasmids) is preferred. Source: Internet
These strains are auxotrophic mutants, i.e. they require histidine for growth, but cannot produce it. Source: Internet