Alkaline Phosphatase Formation in Escherichia Coli Vitamin B12/Methionine Auxotroph.

Alkaline phosphatase has been demonstrated to be strongly
induced in Escherichia coli K12 by growing the cells in a medium
containing low phosphate (1)). This phenomenon was suggested to
be a mechanism of negative feed-back with phosphate serving as
repressor of phosphatase formation although activation during
growth in low phosphate medium was not precluded.
While studying changes in the enzyme make-up of E. coli B12/
methionine mutant growing in phosphate-deficient medium, we had
observed an increase in alkaline phosphatase and to some extent
in ribonuclease activities. These observations prompted us to
examine the nature of elaboration of these enzymes, more so because
ribonuclease is reported to reside in ribosomes of E. coli in a
latent form (2)). In this paper, evidence has been presented to show
that appearance of alkaline phosphatase (phosphomonoesterase)
activity is the result of de novo synthesis of the enzyme protein. The
phenomenon of alkaline phosphatase formation has also been
examined in relation to concomitant nucleic acid synthesis.