Notice of RetractionEffect of pH and Temperature on Activity of Immobilized Lactonase

Notice of Retraction

After careful and considered review of the content of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE´s Publication Principles.

We hereby retract the content of this paper. Reasonable effort should be made to remove all past references to this paper.

The presenting author of this paper has the option to appeal this decision by contacting TPII@ieee.org.

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.