New Scientist, Aug 1 1998, Vol 159, No 2145, p 14
Congratulations to Andrew Ellington and his team at the University of
Indianna. In the recent "New Scientist" is a short and non-technical
article describing experiments on a strain of the bacteria
"Escherichia Coli". This bacteria cannot make its own supply of
the amino acid tryptophan; and so requires a regular external
supply. Ellington and his team gave the long suffering little
critters a supply of the related amino acid flourotryptophan, which
is a poison for life as we know it; initially in a mix of 95% of
the good stuff (tryptophan) and 5% of flourotryptophan.
The bacteria didn't like it: but they coped. Successive generations
also continued to grow (albeit slowly!) as the concentrations
increased.
The end result -- successful evolution of a strain which was able
to live in 100% flourotryptophan and no tryptophan at all, and which
continued to grow slowly after seven generations.
Ellington and his team are now keen to find out what kind of genetic
tricks have been used to cope with and use the poison. The application
considered in the article is artificial evolution of strains of life
able to life on Mars or other non-terretrial environments.
Ellington's home page is
http://www.chem.indiana.edu/personnel/faculty/ellington/ellington.htm
Here he proposes to progressively replace the remaining amino
acids until the bacteria and all of the proteins that it houses
are completely "unnatural," and depend on an entirely new set of
amino acids for function: an ambitious goal!
Richard Harter: take note. I think Ellington's home page URL has
changed recently. Your list should use this new URL, I think.
Cheers -- Chris Ho-Stuart
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