ABSTRACT
Brine pools are deep-sea extreme environments located in the eastern Mediterranean Sea, Red Sea, and Gulf of Mexico. Due to the high salinity and hydrostatic pressure and lack of oxygen and light, they are also known as deep hypersaline anoxic basins (DHABs). Despite the harsh conditions, DHABs support a highly specialized microbial diversity, especially along the steep halocline that occurs in correspondence with the brine–seawater interface, where prokaryotic communities are sharply stratified. The extremophiles able to cope with the particular environmental settings of DHABs and their metabolic capabilities are a cutting-edge topic for biotechnologists aiming to discover and exploit new molecules useful for applications in several fields. For example, extremozymes showing high enantioselectivity in a broad range of pressure, temperature, and pH have been recently identified, while the isolation of bacterial strains from Red Sea DHABs led to the discovery of bioactive molecules active against human cancer cell lines. Due to the difficulties in the cultivability of brine microbes, genomic and metagenomic approaches are also used to investigate the metabolic pathways occurring in the brine pools, thus presenting new opportunities for the discovery of molecules with relevant biotechnological potential from one of the most remote and challenging environments on earth.
