MERCK INSTITUTE
FOR
THERAPEUTIC RESEARCH

RAHWAY, N. J.

November 6, 1951

Dr. Joshua Lederberg
Department of Genetics
University of Wisconsin
Madison, Wisconsin

Dear Doctor Lederberg:

We are sending to you today subcultures of
the Murray strain of E. coli, including the strentonycin-
sensitive and streptomycin-resistant mutants. These are
not the original cultures described in the paper you
cited, since those cultures had unfortunately been lost.
However, the sensitive strain we now have is also a sub-
culture from the "Murray“strain of the N. J. Agricultural
Experiment Station, and the Murray resistant was derived
by the same procedures originally used.

We have not retested these strains for growth
response to aeration, as in Table 1. They have been
checked, however, for their oxidation of pyruvate, oxal-
acetate, and a mixture of these, in the presence and
absence of streptomycin. They were again tested this
week before the subcultures were made for you, in order
to verify their metabolic activity. The results on
these strains are as follows:

Qog (N)
Murray Murray
Streptomycin Sensitive Resistant

Pyruvate - 496 2l6
" + 456 240
Oxalacetate - 328 152
" + 32 152
Pyruvate + Oxalecetate - 408 192
" " + 136 232
Dr. Lederberg -2- November 6, 1951

The data on oxalacetate are higher that those in
Table 2 of "The Action of Streptomycin. II." because the
oxalacetate decarboxylase had not been as completely aged
oute

The new "Gratia" strains which we now have are
somewhat different metabolically from those previously
reported, although the basic pattern, i.e. loss of the
ability to oxidize pyruvate and oxalacetate beyond the
oxidation state of acetate, is also characteristic of
this resistant strain. We should prefer, however, to

investigate these strains further before subcultures are
sent.

Yours truly,

Pret L-Sepuarery-—

ELOs VME Evelyn L. Oginsky