Effect of glycine and its derivatives on production and release of .BETA.-galactosidase by Escherichia coli.

Abstract

Glycine, glycylglycine, glycine methyl ester and glycine ethyl ester were found to be effective for the production and release of β-galactosidase by Escherichia coli. Addition of an appropriate concentration of glycine and glycylglycine to the culture increased total enzyme production 6 to 7-fold and extracellular enzyme production over 240-fold at 24 hr cultivation. The enzyme synthesis was stimulated even at the exponential period of growth, and 93% of enzyme was found in the culture fluid at 24 hr cultivation on addition of 1.2% glycine. A large amount of protein was also accumulated in the culture fluid. A micrograph showed glycine gave swollen and irregular cells, indicating that the cell surface was altered. Various amino acid analogues and some antibiotics had a small or no effect on the production and release of the enzyme as compared with glycine. Polypeptone or brain heart infusion was needed as a nitrogen source for efficient production of the enzyme.