Phystea Chemistry Laboratory,
sduti Parks Road,
‘ Oxford.

20th July 196

Dear Professor Lederberg, ~

We have despatched by air to you a culture on agar of
Bact. lactis aerogenes (aerobacter aerogenes). In an ammonium
‘Bulphate-glucose synthetic medium. an inoculum of the order of
magnitude of a million cells/ml. ghould show a lag of avert
4-7 days after any slight grewth due to “carry over" etc.
On minimal medium-D-arabinégse—-ag plates fully positive colonies
should take a number of days $o aavelop.’ Microcolonies of course
appear rapidly. meta dy

We had not a fregh "yred.
5-10 passages through the Te @ut
quitck after the first) giv
for numerous passages tt — se. I do not believe any
strain is ever wholly stable apa Tr suspect that the arabinose
positive strains would meargy-always require freshening up by
passage through arabinoee afte) storage in broth or on agar.

  

  
  
   
 
   

nea" culture available but
pbinose minimal medium (quite
train which is pretty stable

Yours sincerely,
}

L ee