Development of diatom entrapped alginate beads and application of immobilized cells in aquaculture

Abstract

The objective of this study was entrapment of freshwater diatom Nitzschia palea in a Ca-alginate hydrogel bead through the gelation method. The study further aimed at remediating aquaculture water and its efficient utilization for diatom productivity and futuristic aquaculture applications. Results demonstrate that entrapped diatom in Ca-alginate hydrogel bead showed no swelling behavior​ and they were quite stable during analysis. The maximum cell density was 71.4 × 105 cell mL −1 which was 3.5 times higher than the cell density achieved in free cell culture. The maximum nitrate, phosphate, ammonia removal efficiency was 86.93 ± 3.46%, 57.51 ± 3.8%, 63.83 ± 1.18% which signifies the efficiency of diatom entrapped Ca-alginate hydrogel bead in removing the nutrient load from the aquaculture water. The entrapped diatom cells were quite successful in controlling the water hardness (52.33 ± 2.51%) to a significant level. This work demonstrates that diatom entrapped in Ca-alginate hydrogel bead is a cost-effective method in aquaculture water remediation which can be a long-lasting solution towards sustainability and diverse aquaculture applications.