Biological and chemical characterization of new isolated halophilic microorganisms from saltern ponds of Trapani, Sicily

Abstract

Halophilic microorganisms inhabiting hypersaline environments such as salt lakes, Dead Sea, or salt evaporation ponds, have acquired specific cell adaptation to grow within stressful conditions. In this study, we isolated heterotrophic and autotrophic microorganisms from several saltern ponds located at the Natural Reserve “Saline di Trapani e Paceco”, Sicily, Italy. The aim of the study was to investigate the biotechnological potential of new microbial strains from saltern ponds, by capturing their biological and chemical diversity. After the isolation and identification of the sampled strains, their growth capacity was determined under low and high salinity conditions. The metabolomic profiles of heterotrophs and pigments production of photosynthetic organisms were analyzed. In parallel, antiproliferative tests on human cell lines were conducted with total extracts coming from the microorganism cultures, together with repair activity assessment of non-cytotoxic extracts. Some of the isolated strains were found to synthetize known bioactive molecules and to exert bioactivity on human cells. In particular, the high salinity increases cell repair activity, probably due to an higher production of antioxidants pigments (e.g. lutein and fucoxanthin) from photosynthetic microorganisms; same culture condition augment also concentration of molecules with interesting bioactivities, such as ectoine, betaine, trigonelline, amino acids and oxiglutathione from heterotrophic microorganisms. In conclusion, this work represents the first study on the isolation of halophilic microorganisms populating the ‘Trapani-Paceco’ saltern and shows how an interdisciplinary investigation based on marine microbiology, cell biology, and modern metabolomics can disclose their biotechnological potential.