#auxotroph

• Auxotroph — A mutant organism (especially a bacterial or fungal strain, or a cell culture) that has lost the ability to synthesize a specific organic compound essential for its growth (an amino acid, vitamin, or nitrogenous base) due to a genetic mutation, requiring the mandatory presence of this substance as an exogenous supplement in the culture medium to multiply.
• Auxotrophic — Relating to auxotrophy or to an auxotrophic organism; characterized by the inability to synthesize a specific organic compound essential for growth (amino acid, vitamin, nitrogenous base) due to a genetic mutation, requiring its presence in the culture medium.