Investigating the effect of silver nanoparticles on the activity of glycerol dehydrogenase by response surface methodology

The widely used silver nanoparticles made them readily accessible to the bacteria. The interactions between silver nanoparticles and proteins are still not fully understood. In this research, the effect of silver nanoparticles on glycerol dehydrogenase which is located in the respiratory chain of the Gluconobacter was investigated. Response Surface Methodology and a central composite design were used to evaluate the activity of enzyme and the interactions of pH and temperatures. Enzyme activity was evaluated by colorimetric method. The results showed that increasing the concentration of silver nanoparticles up to 50 mg/L decreased the activity of glycerol dehydrogenase enzyme. The inhibitory effect of nanoparticles decreased beyond this concentration. The glycerol dehydrogenase activity increased 35ºC and pH 7, but the activity decreased thereafter. The parameters of temperature, pH and nanoparticles concentration influenced the activity of glycerol dehydrogenase enzyme independently. It could be concluded that silver nanoparticles decrease the activity of glycerol dehydrogenase, which can ultimately decrease the activity of the respiratory chain and subsequently energy production in Gluconobacter. The results of this research can be used in the targeted control of glycerol dehydrogenase activity to produce dihydroxyacetone.