Jennifer Lynn Giel jlgiel at
Fri Oct 27 08:49:00 EST 2000

Ah, but one wild-type strain of E. coli (W3110) needs thiamine for growth.
Wild-type is an arbitrary definition, anyway.


In bionet.microbiology Rafael Maldonado <rmaldonado at> wrote:

: 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)

Jennifer L. Giel
University of Wisconsin-Madison
580 MSC, 1300 University Avenue
Madison, WI 53706

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