ACETATE INHIBITION ON GROWTH OF RECOMBINANT ESCHERICHIA-COLI AND EXPRESSION OF FUSION PROTEIN TGF-ALPHA-PE40

Acetate was inhibitory to the growth of early induced E. coli cells an d their expression of fusion protein, transforming growth factor-alpha -Pseudomonas exotoxin 40 (TGFalpha-PE40), but the inhibitory level was strain dependent. For E. coli JM109 (pTAC-TGF57-PE40), 2 g/L of added acetate (3 g/L of total acetate in the medium) decreased TGFalpha-PE4 0 production by 38.0%. Acetate was less inhibitory to E. coli RR1, and RR1 was not affected by adding 2 g/L of acetate. However, 5 g/L of ad ded acetate (6.7 g/L of total acetate in the medium) decreased TGFalph a-PE40 production by 21.2%. These results indicate that higher acetate concentration was associated with inhibition of TGFalpha-PE40 express ion of E. coli JM109 during late induction.