auxotroph An organism (usually a bacterium) that, as a result of a mutation, has lost the ability to synthesize a particular substance essential for its growth, e.g. an amino acid or a sugar. The organism must be able to obtain this component from its environment if it is to survive and grow. Compare PROTOTROPH.

auxotroph An organism (usually a bacterium) that, as a result of a mutation, has lost the ability to synthesize a particular substance essential for its growth (e.g. an amino acid or a sugar). The organism must be able to obtain this component from its environment if it is to survive and grow. Compare prototroph.