Thermostabilization of laccase by polysaccharide additives: Enhancement using central composite design of RSM

Stability of laccase from Pleurotus florida NCIM 1243 at high temperature was assessed by combination of polysaccharide additives (Guar Gum and starch). After conducting a series of initial enzyme stabilization experiments, combinatorial additives were selected to construct an appropriate Response Surface Model for optimizing the concentration. Further, sodium acetate buffer was taken as a variable to optimize the polysaccharide additives. The optimum values of these variables for maximum laccase stabilization at 60 °C are Guar Gum (0.098%), starch (6.235%) and sodium acetate buffer (76.84 mM) with a predicted percentage residual activity of 69.91%. The experimental validation for laccase thermostabilization was carried out using optimized variables and was found to be 75%. The significance of the study is that the laccase stabilization was achieved at 60 °C in liquid state rather than in the freeze dried state. The enhancement for stabilization of laccase was 75% and it effectively decolorizes RB198 at 60 °C.