MERCK INSTITUTE
FOR
THERAPEUTIC RESEARCH

RAHWAY, N. J.

May 25, 1950

Dr. Joshua Lederberg

The University of Wisconsin
College of Agriculture
Department of Genetics
Madison 6, Wisconsin

Dear Doctor Lederberg:

Unfortunately, we have not made any partic~
ular progress on the formic hydrogenlyase of E. coli.
We found, indeed, that it would not develop when the
cells were grown on synthetic media, but that the
addition of casein hydrolysate permitted the enzyme
to be formed. We found that the presence of glutamic
acid in the synthetic media permitted the development
of hydrogenlyase activity in the resting cell stage
when casein hydrolysate was supplied to the resting
cells. However, supplying the amino acids, alleged
to be present in casein hydrolysate in the similar
mixture, did not form hydrogenlyase.

This ts about the status of our studies
at the moment and I doubt whether we will get back
to this problem for some time.

Very sincerely yours,

j