An estimate of the extent of deamination of L-serine in auxotrophs of Escherichia coli K-12

Abstract

We have shown that serine–glycine auxotrophs of Escherichia coli K-12 use exogenous L-serine inefficiently as a source of biosynthetic intermediates. Much of the L-serine supplied in the medium is not used to satisfy the auxotrophic requirement, owing to its diversion by L-serine deaminase, presumably to pyruvate. This is the first proof that the activity known as L-serine deaminase actually deaminates L-serine in vivo.