SERGE WAS a

ah

  

Braupschweig,Humboldtstre1.
21 December 1960

Dear Esther! Dear Joshua!

Barbara and I wish Mierry Christmas and happy New Year to yous
It is the first Christmas in your new atrium house and we hope
it will have alwys good stars.

It is difficult to wish happiness because our feeling is
overshadowed from Bobs dead.We was corresponding together about
the possibility to breed Rhizobia for high nitrogen fixation
and large host range.My last letter has been opened by Mr. Brock
from the C.S,I.R.0. in Canberra and he has informed me that Bob
died in the 4th of November.

A fortnight ago I have visited the optical plant Zeiss in
Oberkochen to prove the new Ultramicrospectrophotometer. With this
wonderful apparatus it is possible to measure from ultraviolett
til infrared with a ray from Os Zit diameter running in meander
form or only in diameter.In bacterial stars I get the maximum
absorption in 260m »the DNA maximum,and this maximum is situated
in the starcenter, the pbint of zygote formation. My main work
is now concentrated in increasing the recombination rate during
star firmation or to separate the generatium phase from the
vegetative one in my bacteria. I have some success and it is
quite easy now to demonstrate recombination in B-. Schuster
and Schramm have demonstrated the inactivating or mutagenic effect
of nitrous acid in TMV and Kaudewitz in E.coli caused by the de-
amination of the RNA or DNA ~ bases. I am trying to get mutants
weth this method in Be and it seems with good etfectiveness.

I hope to get now a broad mutant spectrum and to explane the mode
of genetical exchange during starformation,

: Dr.Kaudewitz visited me in Cctober.He is now the successor
of Dr.Nachtsheim in the Max Tlank Institution in Berlin.Dr.Kaude-
witz offered me a zood position in his Institution but here I
have now more scientific independence than in Berlin,

We plan to visite-the microbial congress in Montreal 1962
G80 meetiyou there ore in Stanford. But the realiza~

=

on of th¥e=plaw depends from the monney.
All best wishes from

Bent Sr Te Hef

 

{

YE LN wo
vay baw ask. cya Seta

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