Enhancing Se(IV) bioremediation efficiency via immobilization of filamentous fungi and yeasts in eco-friendly alginate bead hydrogels González-Morales, Eduardo Peula-Ruiz, Esther Newman Portela, Antonio Martín López Tercero, Lidia Medina Castillo, Antonio Luis López López, Modesto Torcuato Merroun, Mohamed Larbi Ruiz Fresneda, Miguel Ángel Aspergillus Rhodotorula Hydrogel This study was supported by grant TED2021-131099B–I00 funded by MCIN/AEI/10.13039/501100011033 (Ministry of Science and Innovation, Spain), and by the European Union NextGenerationEU/PRTR. The authors also acknowledge funding for open access charge: Universidad de Granada/CBUA. The immobilization of microorganisms in polymeric hydrogel has gained attention as a potential method for applications in various fields, offering several advantages over traditional cell free-living technologies. The present study aims to compare the efficiency of selenium (Se) bioremediation and biorecovery by two different fungal types, both in their free and immobilized forms using alginate hydrogels. Our results demonstrated an improvement in the amount of Se(IV) removed from the hydrogels of Aspergillus ochraceus (∼97%) and Rhodotorula mucilaginosa (∼43%) compared to that of the planktonic cultures (∼57% and ∼9–17%). In both cases, most of the Se(IV) is enzymatically reduced by the cells to amorphous Se(0) nanospheres, which are retained throughout the alginate hydrogels. The extensive growth, colonization and distribution of the cells throughout the highly porous hydrogel, along with their ability to maintain viability over long periods and the preservation of the structural integrity of the hydrogel, demonstrated the enormous biotechnological potential of the studied system for practical applications. The results reported show that the immobilization of fungi in alginate hydrogels is an efficient and environmentally friendly alternative for bioremediation and biorecovery of Se nanoparticles, which are of significant industrial and medical interest within the framework of a circular economy. 2025-12-10T08:26:41Z 2025-12-10T08:26:41Z 2025-02 journal article Eduardo González-Morales, Esther Peula-Ruiz, Antonio Martín Newman-Portela, Lidia López-Tercero, Antonio Luis Medina-Castillo, Modesto Torcuato Lopez-Lopez, Mohamed Larbi Merroun, Miguel Angel Ruiz-Fresneda. Enhancing Se(IV) bioremediation efficiency via immobilization of filamentous fungi and yeasts in eco-friendly alginate bead hydrogels, Chemosphere, Volume 370, 2025, 144020, ISN 0045-6535. https://doi.org/10.1016/j.chemosphere.2024.144020 https://hdl.handle.net/10481/108679 10.1016/j.chemosphere.2024.144020 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Elsevier