Optimization of the components concentrations of the lactoperoxidase system by RSM

    loading  Checking for direct PDF access through Ovid


AimsThe aim of this work was to use response surface methodology (RSM) approach, a statistical mathematical tool, to model effects and interactions of glucose oxidase (GOD), glucose, lactoperoxidase (LPO) and pH-values on the thiocyanate (SCN) peroxidation, to determine the best concentrations of lactoperoxidase system (LP-s) components in order to obtain maximal SCN peroxidation and so to enhance the LP-s antibacterial effects.Methods and ResultsExperimental design using RSM was used for modelling effects and interactions of GOD (28·5–142·5 IU l−1), glucose (0·55–11·11 mmol l−1), LPO (0–6284 IU l−1) concentrations, and pH-values (6·0–7·4) on thiocyanate peroxidation. A fixed SCN concentration of 0·5 mmol l−1 was used. Experiments were carried out at 4 or at 25°C in 0·1 mol l−1 phosphate buffer. Optimized concentrations for both temperatures (4 and 25°C) were quite similar and were 85·5 IU l−1 for GOD, 8 mmol l−1 for glucose and 3927·5 IU l−1 for LPO at an initial pH-value of 6·5. SCN peroxidation was more efficient at 25 than at 4°C. At 4°C, no interaction between factors occurred. At 25°C, thiocyanate peroxidation was affected by GOD/glucose, GOD/pH and LPO/pH. Thiocyanate peroxidation was mainly increased by glucose and LPO factors. The optimized system had a bacteriostatic effect on Listeria monocytogenes CIP 82110T and a strong bactericidal effect on Pseudomonas fluorescens CIP 6913T.ConclusionsAppropriate combinations of LPO, GOD, glucose concentrations and pH-values allowed maximal thiocyanate peroxidation and enhanced the antibacterial effect of the LP-s.Significance and Impact of the StudyThis optimization by RSM approach allowed a better understanding of the LP-s functioning, the description of the component impacts on the SCN peroxidation, and the observation of different interactions between the factors. The antimicrobial efficiency of LP-s can be enhanced by better concentration ratios of the LP-s components.

    loading  Loading Related Articles