Notice of RetractionEffect of pH and Temperature on Activity of Immobilized Lactonase
This work presents as a main objective to study influences of the pH and temperature on the activity of immobilized lactonase which converts D-pantoyl lactone stereospecifically to D-pantoic acid. The result indicated that the optimum pH of immobilized and free lactonase was 7.5. However we found that the change of free enzyme activity with the pH was faster than the immobilized enzyme. And the pH stability range of immobilized enzyme was 6.5 ~ 8.5, which was broader than that of free enzyme (pH 7-8). The result indicated that immobilization of free enzyme led to a shift of catalysis optimal temperature towards higher values. The optimum temperature of free lactonase and the immoblized enzyme were 30°C and 40°C respectively. The thermostability of the immobilized enzyme was obviously better than free enzyme.