UNIVERSITY OF HOUSTON
DEPARTMENT OF BIOLOGY
CULLEN BOULEVARD
HOUSTON 4, TEXAS

April 24, 1959

Dr. Joshua Lederberg
Department of Genetics
School cf Medicine
Stanford University
Stanford, Celifornia

Dear Dr. Lederberg:

Please forgive me for my delay in answering your letter of
April 10th. I have been away from the office on a business trip.

I have given considerable thought to your question pertaining
to the decontamination of interplanetary missles and I shall try to
discuss my thoughts on this problem.

Missles of this type contain machined metal parts. The parts
are composed of brass, aluminum, and steel and small quantities of
other metals. These parts should be contaminated with Pseudomonas
species, Escherichia coli, Proteus species and paracolon bacteria.
These organisms are capable of surviving on metal surfaces and should
be on the parts. Sometimes machined metal parts are washed to remove
oil and other material and in this case the flora should be markedly
reduced. The parts may be handled enough in the process of assembly
to contaminate them with bacteria found on the human skin. As a
matter of fact I believe all of the parts of the "bird" should be
contaminated with bacteria associated with man. When one considers
the time and labor that is needed to construct some of the electronic
components it would seem that considerable contamination should take
place. In addition, I would suspect that there should be an influx
of microorganisms that are associated with the deterioration cf the
materials in the missles. These rockets are sent up from humid
subtropical and tropical or subtropical steppe areas (Florida and
California) in this country. The missles are usually in storage in
these regions for several weeks or months while final assembly and
stationary ground tests are made. I suspect this is ample time for
contemination of the parts to teke place.

 
-2-

The glass in the electronic equipment should contain fungii
in addition to bacteria. The wire insulation should contain
Mécrococcus species, Psuedomonas species, Flavobacterium species,
Mycobacterium species and Corynebacterium species. These are the
bacteria found on plastic coatings according to a confidential report
that I have in my files.

The electronic systems contain some shellac. This material
can support the growth of moulds and bacteria.

There are a lot of materials in the rocket thet are new and
have not been studied for their microbial load. For example, what
types of bacteria are found on recording tape, and the new ceramic
materials?

There is one factor in your favor in decontamination of these
rockets. There must be a considerable reduction in microbial load
due to irradiation at high altitudes. This should reduce the load
considerably, however, I don't think anyone knows how much.

I believe a lot of tests will have to be made before you will
have the answer to your problem. I believe the only thing one can
do is get the parts and study their flora. This will be a big job.

I certainly hope this information is of value in your work.

We have talked about adding a new staff member in microbial
genetics during the 1960-61 academic year. Do you have any graduate
students that will complete their work at that time who might be
interested in a position on our staff?

The state SAB chapter has a annual I. M. Lewis lecture in
bacteriology. This lecture will be given in October or November of
this year. I wonder if we could prevail on you to give this lecture.
We shall be most happy to pay your travel expenses and there is an
nonorarium for the talk. The meeting will be here in Houston and we
would undoubtedly have a large crowd for such a distinguished lecturer.
I shall look forward to any remarks you may have pertaining to this
question.

I shall consider it an honor to be able to help you in any way

with your problem. Please do not hesitate to write if you feel I can
be of value.

Kindest personal regards,

AM en

E. O. Bennett

EOB: 11