A mathematical model was developed to predict breakthrough curves during purification of the two chitosanases from Metarhizium anisopliae by expanded bed adsorption, taking into account the axial dispersion of liquid and using Streamline DEAE and SP XL adsorbents, anion and cation exchange resins, respectively. All the experiments were performed without clarification (with cells) aiming at the reduction of unit operations in future projects of separation processes, thereby reducing capital and operating costs. Chitosanases are enzymes that hydrolyze the carbohydrate chitosan, resulting in oligosaccharides that have many remarkable biological activities, such as anti-cancer, anti-HIV and antioxidant activities. The two adsorbents had similar performance in relation to hydrodynamics and mass transfer. The results of the parametric sensitivity analysis agree with the literature, and the model was validated with an average high degree of fit (94.68%) between simulated and experimental data obtained in this work.