ABSTRACT
The halophilic microorganisms are present in all three domains of life: Archaea, Bacteria, and Eukarya. They have the unique property of thriving in an environment characterized by high salt concentration and are widespread in hypersaline lakes, solar salterns, saline soil, evaporation ponds, and marine environments. As in such extreme environments, the salt concentration can reach the saturation, halophiles succeed to survive by adopting several strategies: moderate halophiles accumulate in the cytoplasm huge quantity of organic compounds which function as osmo-protectants; conversely, extremely halophilic microorganisms store in the cytoplasm potassium chloride offering an osmotic balance between cells and medium. Moreover, these microorganisms have developed unique enzymes that are stable and active in the presence of salts and interesting biomolecules with protective functions such as exopolysacchyarides (EPS), pigments, and polyhydroxyalkanoates (PHA). Many halophilic microorganisms exhibit antimicrobial properties as they produce bacteriocin-like peptides known with the name of halocins.
As a consequence, the halophilic microorganisms are regarded as amazing tools for producing compounds of significant importance for industries because they can found applications in many fields, such as pharmaceutical, food, and cosmetics. This review reports an overview of the most useful ‘halophilic products’ produced by bacterial, archaeal, and eukaryal halophiles and their biotechnological potentials.
