Parameters optimization of recombinant hepatitis B antigen adsorption–desorption in purification process on three different kinds of diatomaceous earth matrix

The purpose of this study was to compare adsorptive capacity of three kinds of celite for r-HBsAg. The experimental design methodology was used to optimize the parameters which affect adsorption efficiency. The examined parameters were the adsorption/desorption temperature, pH, time, agitation speed and antigen concentration. Maximum adsorbed/desorbed efficiency for Celite-A, Celite-B and Celite-C were obtained in optimum parameters, 78%, 45% and 88% respectively. Batch shaking experiments were performed to examine the effects of initial solution pH, agitation speed, contact time and initial antigen concentrations. The maximum adsorption capacity for hepatitis B antigen was obtained 66.2 μg g −1 , 32.4 μg g −1 and 72.6 μg g −1 for Celite-A, Celite-B and Celite-C in case of experimental optimal conditions, respectively. The results indicated that Langmuir isotherm provide the best correlation of experimental data for Celite-A and Celite-C, while the Freundlich isotherm better fitted to experimental data for Celite-B. Results also indicated antigen adsorption onto the celite is best represented with a pseudo second-order kinetic model. Surface characterization was performed by FTIR and FESEM analysis.