FROM POLAR REGIONS TO VOLCANIC AND HYPERSALINE AREA : BIOSYNTHESIS, CHEMISTRY AND APPLICATIONS OF EXOPOLYSACCHARIDES BY EXTREMOPHILES

Extremophiles have developed various adaptations, enabling them to compensate for the deleterious effects of extreme conditions as high temperatures, salt presence, low pH values, or high radiation levels. Among the adaptive strategies, exopolysaccharide (EPS) biosynthesis is one of the most common protective mechanisms. Although the EPS production is a process that requires a significant carbon investment for microorganisms, the benefits are significantly higher than costs considering the cell survival in their presence. These biopolymers have emerged as new polymeric materials with novel and unique physical characteristics that have found extensive applications in food, pharmaceutical, and other industrial fields. The increasing demand of natural polymers for industrial applications has led to a vibrant interest in the EPS production by microorganisms. There has been a substantial attractiveness in the isolation and identification of new microbial polysaccharides that might have innovative uses as emulsifiers, stabilizers, and gelling or texture-enhancing agents. Recent research on polysaccharide produced extremophiles, isolated from hypersaline environments, deep-sea hydrothermal vents, and volcanic and hydrothermal areas, will be reported including chemical structures, fermentation technology, biotechnological and biomedical applications.