Deep Hypersaline Anoxic Basins as Untapped Reservoir of Polyextremophilic Prokaryotes of Biotechnological Interest

Abstract

Deep-sea hypersaline anoxic basins (DHABs) are considered to be among the most extreme ecosystems on our planet, allowing only the life of polyextremophilic organisms. DHABs’ prokaryotes exhibit extraordinary metabolic capabilities, representing a hot topic for microbiologists and biotechnologists. These are a source of enzymes and new secondary metabolites with valuable applications in different biotechnological fields. Here, we review the current knowledge on prokaryotic diversity in DHABs, highlighting the biotechnological applications of identified taxa and isolated species. The discovery of new species and molecules from these ecosystems is expanding our understanding of life limits and is expected to have a strong impact on biotechnological applications.

Diversity, Ecological Role and Biotechnological Potential of Antarctic Marine Fungi

“…There is a general consensus that natural products offer extraordinary advantages over chemical molecules, and this makes marine microorganisms an astonishing potential source of new drugs [ 150 , 151 , 152 , 153 , 154 ]. Marine extremophilic microorganisms, including fungi, can also represent a huge reservoir of bioactive molecules that have recently triggered interest in bioprospecting research because of their promising therapeutical properties [ 21 , 22 , 29 , 109 , 152 , 155 , 156 , 157 , 158 , 159 ]. In this regard, marine fungi isolated from polar environments reported their ability to synthesize metabolites with unique structures and a wide range of biological activities, compared to mesophilic fungi, highlighting that psychrophilic fungi can be a new resource for several applications in biotechnology [ 28 , 30 , 160 , 161 , 162 ].…”

Recent Development of Extremophilic Bacteria and Their Application in Biorefinery

“…The huge technological gap between producing enzymes in laboratory conditions and obtaining the final commercial product is a challenge when developing extremozymes. It can be seen that a large number of extremozyme-related papers are published every year, but they rarely achieved industrialization (Di Donato et al, 2018;Jin et al, 2019;Varrella et al, 2020). In recent years, more and more scientists have devoted themselves to these issues affecting the application of extremophiles in the field of biorefinery, and they have obtained many achievements.…”

Bioactive Molecules from Extreme Environments

“…New DHABs, the Thetis, Kyros and Haephestus basins in the Mediterranean Sea, have been recently discovered. DHABs are microbial “hotspot”, with dense microbial populations of unique bacterial lineages more metabolically active than those of the adjacent layers [ 7 ]. Deep-sea extremophiles, able to proliferate under these challenging parameters (pressure and temperature, pH, salinity and redox potential), have adopted a variety of strategies to cope with these extreme environments, such as the production of extremozymes, with thermal or cold adaptability, salt tolerance and/or pressure tolerance, and secondary metabolites with biomedical applications.…”

“…Varrella and colleagues 2020 [ 7 ] in their review described the environmental characteristics of DHABs, highlighting the unique bacterial lineages found in these extreme habitats. DHAB-derived microorganisms represent promising candidates for the bioremediation of oil hydrocarbons thanks to the presence of enzymes involved in pathways associated with hydrocarbon degradation.…”