In this work, a native exopolysaccharide (nEPS) produced by Halomonas desertis G11 isolated from a Tunisian extreme environment was modified by gamma irradiation. Characterization as well as the antioxidant and antitumor activities of nEPS and its gamma-irradiated derivatives (iEPSs) were comparatively evaluated. In vitro and in vivo antioxidant potentials were determined by using different methods and through different antioxidant enzymes. The antitumor activity was checked against a human colon cancer cell line. Analyses of the complete genome sequence were carried out to identify genes implicated in the production of nEPS. Thus, the genomic biosynthesis pathway and the export mechanism of nEPS were proposed. Analyses of irradiation data showed that iEPSs acquired new functional groups, lower molecular weights, and gained significantly (p < 0.05) higher antioxidant and antitumor abilities compared with nEPS. These findings provide a basis for using iEPSs as novel pharmaceutical agents for human therapies.

This investigation advances kesterite photovoltaic technology through optimized Cu₂ZnSnS₄ (CZTS) absorber design, capitalizing on its earth-abundant and eco-friendly characteristics. Although CZTS devices with CdS buffers are currently limited to a certified efficiency of 13.44% (well below the standards of CIGS/CdTe), we demonstrate that integrating a FeS₂ back surface field offers a promising alternative pathway for enhancing efficiency. Our spray pyrolysis synthesis yields uniform CZTS nanostructures, with gamma irradiation studies revealing dose-dependent modifications. Numerical simulations using Silvaco TCAD confirmed notable performance improvements in the engineered Al/ARC/FTO/ZnO/CZTS/FeS₂/Mo architecture, achieving a short-circuit current density (J_sc) of 17.70 mA/cm², open-circuit voltage (V_oc) of 1.20 V, fill factor (FF) of 85.32%, and overall power conversion efficiency (PCE) of 18.06%. These findings establish a new paradigm for high-efficiency, sustainable thin-film photovoltaics.