Marine halophilic archaeal isolate Halococcus sp. with emphasis on bioremediation of radionuclides through extracellular biomolecules

Abstract

AbstractBACKGROUNDMarine archaea have gained special attention for their unique ability to survive in extreme salt concentrations. Some archaeal isolates have been found to thrive in the presence of radioactive contaminants. In this study, Halococcus sp. ENMS8 has been isolated from marine sediment sample with special emphasis on bioremediation of radionuclide cesium.RESULTSHalococcus sp. ENMS8 has the ability to remove 76.46% of cesium ions noted at a concentration of 100 mmol L−1 followed by 60.5%, 52.16% and 42.9% of cesium ion adsorption at concentrations of 150, 200 and 250 mmol L−1 Cs+, respectively. The minimal level of 4.43% of cesium adsorption was noted at 500 mmol L−1 concentration in the presence of 106 archaeal cells per milliliter. Similarly, adsorption of cesium (500 mmol L−1) at various concentrations of archaeal extracellular polymeric substances (EPS) has been shown to be 76.4% of Cs+ adsorption at 1 g L−1. The composition of extracted EPS from ENMS8 in the presence of CsCl and control has been estimated. Cesium adsorption was further confirmed with Fourier transform infrared spectroscopy, and scanning electron microscopy was used to obtain high‐resolution images of the surface topology of Halococcus sp. ENMS8 EPS in the presence of cesium. The crystallographic structure and properties of cesium were studied by energy‐dispersive X‐ray spectroscopy.CONCLUSIONThe present study concluded that Halococcus sp. ENMS8 can immobilize cesium through EPS in an eco‐friendly approach. © 2023 Society of Chemical Industry (SCI).