UnIversity oF MINNESOTA

Tur MepicaLt ScHoon

Minneapouis 14

DEPARTMENT OF BACTERIOLOGY
AND IMMUNOLOGY

Dr. Joshua Lederberg
Department of Genetics
University of Wisconsin
College of Agriculture
Madison 6, Wisconsin

Dear Joshua,

I have spent some considerable time during the last few weeks
studying the strain of E. coli that you sent me under the label of
W-2754. This is a most interestinz strain, biochemically speaking,
and I hope to find time in the near future to study it much more
intensively. At the moment, the sugur fermentation reaction of this
strain of E. coli is definitely different from other strains as you
pointed out in your letter. I have checked it during growth and find
that it is negative on sucrose, it produces only acid on maltose, lactose
and glucose. However, it does ferment mannitol with both acid and gas.
I have done several experiments with resting cell suspensions 2nd find
that there is a very low, but definite rate of fermentation of pyruvate,
formate, and glucose. The rate on glucose is much better than on
pyruvate or formate but only a very small amount of the glucose is
fermented, at least to gas. The fermentation of manitol is adaptive
end fructose is utilized at a distinctly greater rate than glucose. I
have tried to stimulate the rate of fermentation of these sugars and
find that several can be stimulated by yeast extract. However, so far,
nothing has stimulated the rate on pyruvate. It is also of considerable
interest that I have not been able to detect the production of hydrogen,
that is, all of these fermentations that i nave mentioned produce carbon
‘dioxide but not hydrogen which is quite suprising. There is no doubt
at all but that this organism should be studied quite intensively because
I feel that we can learn something about the general fermentation of
hexoses from the study of this organism. However, I am going to have
to table this problem for a while since several other things require my
immediate attentions I do hope that I can get back to this personally
during the summer or, if not, that I can have one of my students pursue
the problem a bit more.

Thank you again for making this strain available to me and I shall
let you know, from time to time, of our progress.

With best personal regards,

Sincerely yours,

Aetna

Herman C. Lichstein
Associate Trofessor of
Bacteriology and Immunolozy

HCL: pao