A simple method for cell disruption by immobilization of lysozyme on the extrudate-shaped Na-Y zeolite: Recirculating packed bed disruption process

Abstract

Carrier-based immobilization has been developed to improve the functional properties of enzymes and promote the employment of enzymatic lysis in downstream processing without the necessity to separate the lysis enzyme after processing. In this study, lysozyme was immobilized on an extrudate-shaped Na-Y zeolite and was used for the disruption of Micrococcus lysodeikticus in a recirculating packed bed reactor. The factors influencing immobilization process, namely, liquid velocity and initial concentration of lysozyme solution, were studied aiming to improve the amount of immobilized lysozyme. Additionally, the key process parameters of cell disruption operation using lysozyme-zeolite complex in recirculating packed bed reactor, including the volume of M. lysodeikticus suspension, liquid velocity and operating temperature, were further investigated for their effects on the efficiency of cell disruption. Under the optimal conditions (50 ml of 2.0 mg/ml cell suspension, liquid velocity of 500 cm/h, and operating temperature of 25 °C), the system successfully achieved cell disruption yield of 93% and released protein content of approximately 400 μg/ml. Besides, the system demonstrated its reusability by acquiring released protein content of 250 μg/ml after 12 successive cycles of operation.