STIMULATORY EFFECTS OF AMINO-ACIDS AND OLEIC-ACID ON POLY(3-HYDROXYBUTYRIC ACID) SYNTHESIS BY RECOMBINANT ESCHERICHIA-COLI

Addition of cysteine, isoleucine, methionine, or proline promoted poly (3-hydroxybutyric acid) [PHB] synthesis by recombinant Escherichia col i more than two-fold. Oleic acid also enhanced PHB synthesis more than three-fold. A PHB concentration of 70 g/l could be obtained by fed-ba tch culture of recombinant E. coli in a defined medium supplemented wi th small amounts of isoleucine, methionine, and proline. The stimulato ry effects of amino acids and oleic acid on PHB synthesis seems to be due to the availability of more acetyl-CoA and/or NADPH.