November 135, 1952

Dr. S. Graniock

Rockefelier Institute for Medical Research
66th Street and York Avonue

New York 21, N.Y.

Dear Granick:

I will be happy enough to send you K-12-- but you can ptobably get it
more quickly by phoning Bernie Davis across the street. The fact that it
carries a symbiotic phage should be absolutely immaterial for your purposes.

Qn the other hani, I am rather doubtful that 5. cold ie well suited
in ite physiological behavior for your very interesting project. It never
does oxidize very rapidly, and its cytochromes are just barely detectable
by spectroscopy of the indephenol reaction. I do applaud your aim to use
@ sexual organiem, but there are no other bacteria which are so far available
from this viewpoint. I suspect that you will have to compromise in one of
the following directions:

a) Use a bacterium amenable to the penicillin method. I think that Pseude-
monas fluorescens is the best bet. It is a strict aerobe, is sasily cultivated,
and is quite amenable to penicillin eslection. I have played with it just a
bit-- Bernie, again, has the wild type strain I used (ask him for Pr~15, wheh
is the same ac Stanier's 43.12) as well as some interesting auxotrophs I made
awhile ago. Pseudomonas is loaded with cytochromees Azotobacter is even
more heavily loaded (packed cells have a distinct red color), mut it might be
a little more difficult to handle. You could check with Perry ‘/ilemn here (or
I will if you prefer) on some incidental genetic work that has bean done on
Azotobacter.

») Use another organism, without the advantage of the penicillin method.
In almost every respect, yeast is the obvious bug. There has already been a
certain amount of work on cytochrome-deficient mutants, although not from $e
viewpoint of porphyrin synthesis. There is a great fund of genetic information
generally, as weil, of course, ae an accumulated tradition on cytochrome, Pas-
teur effect, etc.

My own preferehce would be for b). Although penicillin preswsably would not
work, it may be feasible to find other agents with a comparable effect (I don't
imow of any work on this, penicillin or otherwise). In addition, the replica-
plating method (J. Bact. Hare or April '52) makes the penicillin method less
indispensable anyhow.

If I can provide any cultures, or help in any other way, please let me
know. I will be most interested to hear how this turns out. I have had a specu-
lative interest in the cytoplasic control of respiratory metabolism fer some
time, but hase never gone so far as ¢o do anything about it. Sincerely