Immobilization: the promising technique to protect and increase the efficiency of microorganisms to remove contaminants

Abstract Biodegradation of pollutants is one of the most economical methods for their removal and usually is accompanied by no production of toxic by‐products. In general, this approach is favored over others because it offers reduced expenses and the potential for complete mineralization. In order to enhance the viability and longevity of the bioremediation agents within polluted areas, it becomes necessary to immobilize the cells. Cell immobilization refers to the procedure of confining intact cells to specific areas within a device or material, without compromising their essential biological functions. A wide variety of carriers and approaches have been used for the restriction of various cells. Immobilization techniques, such as microencapsulation, have opened up new possibilities in biotechnology by facilitating the development of artificial organs, cell therapies and drug delivery systems. Researchers have found promising outcomes in various applications through the immobilization of microorganisms. This approach enhances stability, reusability and catalytic efficiency, making immobilization a valuable strategy for biocatalysis, bioremediation and other biotechnological processes. Notably, the use of immobilized microorganisms has led to significant improvements in the removal of pollutants, with some studies achieving 100% efficiency. When comparing the degradation of pollutants between free and immobilized microorganisms over the same time period, the results demonstrated that immobilized microorganisms achieved a removal efficiency >21% more than that of free microbial consortia. The primary objective of this review is to give an overview of the key scientific aspects related to bioremediation of various pollutants using immobilized cells, with a particular focus on the techniques used to entrap the cells. © 2024 Society of Chemical Industry (SCI).