Exopolysaccharide producer microorganisms from extreme areas: chemistry and application.

Microbial EPSs are ubiquitous in the extreme environments where they are crucial for microbial survival. Most of the functions attributed to EPSs are related to a protective role, which are dependent on the ecological niches in which the producer microorganisms live. They could support the microbial communities to tolerate extremes of temperature, salt concentration and nutrient supply, building an interface between the bacterial cell and its surrounding environment. Several EPSs produced by microorganisms from extreme habitats show biotechnological promise. By examining their structure and chemical/physical characteristics, it is possible to gain insight into their commercial application; they are employed in several fields ranging from food-processing to pharmaceutical industries, through to the bioremediation ability of polluted areas. Considering that most of extreme ecosystems and, therefore, the respective microbial communities are still unexplored, it is reasonable to hypothesize that the isolation of new microorganisms, together with their biomolecules, in particular exopolysaccharides, will provide interesting perspectives for new industrial processes in several fields.