Identification and molecular characterization of a metagenome-derived L-lysine decarboxylase gene from subtropical soil microorganisms
Fig 6
Effects of temperature and pH on the activity and stability of Ldc1E.
(A) Optimum reaction temperature of the recombinant Ldc1E. The enzyme activity was measured at various temperatures from 20°C to 60°C with 5°C intervals in 0.2 M Na2HPO4/0.1 M citric acid buffer (pH 6.5). Relative activity of 100% represents the specific activity of 1.50±0.06 U mg−1 protein. (B) Effect of temperature on the enzymatic activity of recombinant Ldc1E. Relative activity of 100% represents the specific activity of 1.53±0.06 U mg−1 protein. (C) Effect of pH on the enzymatic activity of recombinant Ldc1E. The enzyme activity was measured in 0.2 M Na2HPO4/0.1 M citric acid (4.0–8.0) and 0.1 M glycine–NaOH (8.0–10.0) at 40°C. Relative activity of 100% represents the specific activity of 1.53±0.06 U mg−1 protein. (D) Effect of stable pH on the enzymatic activity of the recombinant Ldc1E. Relative activity of 100% represents the specific activity of 0.93±0.05 U mg−1 protein.