Rafael Maldonado rmaldonado at
Wed Oct 25 03:11:45 EST 2000

Emir Khatipov wrote:
> It does not have to be a mutant. 

Sorry, I don't agree. An auxotroph is a mutant strain which need a
nutritional requirement that the wild type does not require. It is the
only way to detect a auxotrophic requirement. Whitout this premise,
every living organism is auxotroph (except some cyanobacteria, which can
live with practicaly air and sunlight)

For example, Homo sapiens is not a auxotroph of vitamin C, because
although people need vitamin C for living, the wild type (actually,
everybody) does need it.

Auxotrophic organism would just have a
> requirement in a certain or a number nutrients/factors for growth, e.g.,
> some photosynthetic bacteria require group B vitamins.
> Prototroph is an antonym for auxotroph (in case that the auxotrophic
> phenotype is a result of a known mutation).

Rafael Maldonado
Divison of Genetics
University of Alicante (Spain)

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