Cell immobilization: An overview on techniques and its applications in food industry

Abstract

Immobilization is the term that expresses something immobilized or fixed. The process involves the immobilized biocatalyst, enzymes or cells that are physically fixed in a defined region for catalyzing a specific reaction with no loss of catalytic activity and with repeated use. Immobilization techniques of cells have properties such as high bio catalytic activity, long term stability of cells, and possibility of regenerating bio catalysts and low loss of activity during immobilization. Besides they improve enzyme properties by increasing stabilization and rigidity of 3D structures and reduce enzyme inhibition. Different immobilization techniques are presently in use today viz., physical adsorption, encapsulation and entrapment, cross-linking method and covalent binding. Immobilization finds extensive use in food industry mainly for starch processing. Cheese making, food preservation, lipid hydrolysis and other applications. Other than food industry, immobilization technique finds tremendous applications in pharmaceutical and biochemical industry. Besides biological waste water treatment by immobilization of catalysts, microbial adhesion has been studied intensely for water pollution treatment. However, cell immobilization system also presents some disadvantages on account of diffusion barrier properties of matrix and unrestrained growth due to cell begin in different growth phase that can burst the support matrix employed for entrapment of organism which may contaminate the product in production media.