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Chapter 24 : A Failed Experiment
In 1956 I joined Ole Maaløe’s laboratory in Copenhagen for a two-year postdoc. We worked on the connection between the rate of growth of Salmonella and its macromolecular composition, arriving at the conclusion that there was indeed a simple linear correlation between the cells’ nucleic acid and protein content and how fast they were growing. In trying to interpret this, Ole was influenced by the experiments coming from the labs of quite a few people, showing that the synthesis of many biosynthetic enzymes becomes repressed when the end product of their pathway is added to the medium. If, say, arginine is added to a culture, the enzymes involved in arginine biosynthesis will not be made. If so, in cultures grown in a rich broth, many biosynthetic genes should indeed be silenced. These should include all the operons for amino acid biosynthesis and for other building blocks present in this medium.