March 13, 1969

Dr. R. N. Mukherjee

Unit of Radiation Biology
Division of LIfe Sciences, IAEA
Vienna 1, Kaerntnerring
Austria

Dear Dr. Mukherjee: yh

Dr. A. H. Sparrow has mentioned that you are trying to coordinate and

collect information on radio-resistant organisms in "liquids used for
shielding nuclear reactors".

I have no useful information to offer you, but would appreciate your
letting me know of any papers that may have been published on this
question. In 1957 I visited the reactor at Trombay and was quite
astonished to see the density of blue-green algal growth in the swimming-
pool reactor. Subsequently, I believe I saw a note on the question in
Nature, but have not been able to retrieve the reference.

My immediate interest in the question has to do with possible sources
of radiation-resistant bacteria, and we have already found some inter-
esting organisms, different from Micrococcus radiodurans, at the Brook-
haven site,which we are exploring further for genetic investigations.
If you can let me have a list of published reference on organisms in
reactor pools, as well as any other information that you might have

for my immediate research interest, I would be most grateful to you.
The particular direction of my interest is to investigate possibly
diverse mechanisms of repair of radiation-damaged DNA in bacteria.

Sincerely yours,

Joshua Lederberg
Professor of Genetics