Synthesis of Serine by Micro-organisms

Abstract

FOR some years there has been indirect evidence (reviewed, for example, by Woods¹) that p-amino-benzoate has a function in the synthesis by micro-organisms of certain nucleic acid components and amino-acids. In the case of the former substances it is probable that the effect occurs through the intermediate formation of folic acid (pteroylglutamate) or related compounds which contain a p-aminobenzoate residue. One of the amino-acids implicated above is serine², and this was chosen for the present studies since Sakami³, working with animal tissues, has shown its formation by condensation of glycine with a one-carbon compound such as formate. There is also evidence with several micro-organisms that glycine is a precursor of serine^4,5. Holland and Meinke⁶ have found that under certain limited conditions Streptococcus fæcalis R requires serine for growth, and that such requirement may be largely abolished by increasing tenfold the concentration of pteroylglutamate.