Several microalgae synthesize metabolites of great commercial interest. Microalgae also act as filters for wastewater N and P, heavy metals, and xenobiotic compounds. However, the cost-effective harvesting of microalgae is one of the major bottlenecks limiting the microalgal biomass applications. In this context, immobilization of algal cells has been proposed for circumventing the harvest problem as well as retaining the high-value algal biomass for further processing. In recent years, innovative approaches have been employed in the field of coimmobilization and microencapsulation, which have proved the superiority of immobilized cells over the free cells. Further, the development in the field of biosensor technology with immobilized microalgae presents an early warning device to monitor pollutants in natural waters. This chapter reviews the various applications of immobilized microalgae and addresses the specific methods concerning the production of coimmobilized beads and the protocol for construction of optical algal biosensors.
Keywords: Bioreactor; Biosensor; Coimmobilization; Heavy metals; Microalgae; N and P removal.