Casero, María CristinaVelázquez, DavidPereira, AdriánTejedor, María del MarGarcía, LuisQuesada, AntonioCirés, Samuel2025-11-132025-11-132024-12Casero, M. C., Velázquez, D., Pereira, A., Tejedor, M. d. M., García, L., Quesada, A., & Cirés, S. (2024). Hidden inside desert rocks: Salinity triggers an increase in exopolysaccharides from endolithic cyanobacteria with anti-inflammatory potential. Algal Research, 84. https://doi.org/10.1016/J.ALGAL.2024.1038172211-926410.1016/j.algal.2024.103817https://hdl.handle.net/20.500.14352/126058This work was funded by Comunidad de Madrid and Universidad Autónoma de Madrid via LIPEPSTREM project [grant number SI3/PJI/ 2021-00461] and by MCIN/AEI/10.13039/501100011033/ FEDER, UE, via MERIDIAN project [grant number PID2022-136691NA-I00]. M. C. Casero is the recipient of a Juan de la Cierva-Formación postdoctoral grant [FJC2020-044126-I] funded by MCIN/AEI/ 10.130 39/501100011033 and by European Union NextGenerationEU/PRTR.Endolithic cyanobacteria thriving in rocks of deserts remain an unexplored source for the quest of novel bioproducts in extreme environments. In this work, 7 endolithic cyanobacteria from the polyextreme Atacama Desert, covering four genera and three lithic substrates, were investigated for the production of exopolysaccharides with anti-inflammatory potential. A moderate salinity (20 g NaCl L− 1 ) was tolerated by all strains, triggering a 3–9-fold increase in exopolysaccharides (EPS) yield in 4 of them that counteracted the growth decrease due to NaCl stress. EPS from all strains showed anti-elastase activity with inter-strain and inter-salinity variations. The moderate EPS productivity by Gloeocapsa sp. UAM572 (0.4 mg EPS L− 1 day− 1 ), elevated antielastase capacity of Chroococcidiopsis sp. UAM579 EPS (IC50 = 78 μg mL− 1 ) and the first biotechnological data of genus Pseudoacaryochloris, provide a promising foundation for potential applications of EPS from endolithic cyanobacteria in cosmetics and biomedicine, whose opportunities and challenges are discussed herein.engAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/journal articlehttps://doi.org/10.1016/j.algal.2024.103817https://www.sciencedirect.com/science/article/pii/S2211926424004296?via%3Dihubopen access579.6582.232(835.16)60577.11ExopolysaccharidesAnti-inflammatorySalinityCyanobacteriaDesertElastaseHalotolerantMicrobiología (Biología)Botánica (Biología)BiotecnologíaBioquímica (Biología)2414 Microbiología2417 Biología Vegetal (Botánica)2403 Bioquímica2304.19 Polisacáridos