Siena,November 6,1950
Dear Prof.Lederberg,
I have sended you the requested strains E. Coli I,E.Coli SG,E.Coli
UQ and the matant tee E.Coli I s¢ I6(vhich was obtained from
E.Coli I by imtnent aise 16 passages: with the nucleoprotein frac=
tion isolated. from Coli SG}.
I have controlled their biochemic: 1 activities ,which are below
sumuarized(The. data are expressed as Q0,va lues ;Varburg “anometric

technique)... oo

Strain Control tsucrose +mannitol +xylose -lactose +fructose

E.Coli IT 10.3 10.02 37.) 21.5 20.2 27.6
E.Coli SG 9.68 19.2 22 oh 20.1 2.5 28.6
E.Coli UQ 12.42 32.07 35.2 26.12 27.9 2h, 63
E.Coli ISG I0.I2 18.7 29.1 21.06 26.9 20.9
T6(mitant)

As you may seen thée strains E.Coli I and E.Coli I SG I6 have
maintained tineltered the chemical activities which are described

in my pap-r. The strains E.Coli SG and UQ,which are conserved in

the Collection of the Istituto Sieroterapico Vaccinogeno Toscano
and were cultivated in the past yaar on common avar environments,
have acquired the ability to oxidize xylose and mannitol respective?
ly, which were missing in the strains which were furnished us by

the same Institute an year ago.

I hope that you can be able to obtain good results in your experi=
ments with my streins.I feel very much honoured for your request

and for your consideration of my work.
me
I should be very obliged to vou if you could give“information

on your further results.
I vrenain at your complete disposal for eventual future informa=
tions on the strains which I have sended you.

Thanking you very much,I am
. yours, sincerely

Mario Umberto Dianzani,M.D.,Ph.D.

Istituto di Patologia Generale
dell' ‘niversité& di Genova(Italy)

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