Extremophilic yeasts and their potential in bioremediation of polluted environments

Extreme ecosystems on Earth determine the diversity and abundance of specific microorganisms. Extremophilic and extremotolerant prokaryotes are the most abundant in most environments with harsh conditions for diverse life forms. Eukaryotic organisms are less abundant in these extreme environments; however, some microscopic eukaryotes have successfully thrived in various inhospitable environments. Although the role and participation of such eukaryotes in ecosystem ecology has yet to be studied, a few eukaryotic species have been described and their potential application in different industries has been prioritized. In addition to this potential, the application of native yeasts in bioremediation processes is a little studied topic, despite the potential that these extremophilic and extremotolerant yeasts have demonstrated. A great diversity of yeasts with characteristics to thrive in adverse conditions has been studied and classified (psychrotrophic, psychrophilic, piezophilic, halophilic, xerophilic, among others). This variety must be identified through molecular and physiological mechanisms that allow them to overcome difficult environments for the growth of all life. Based on this knowledge, potential applications in the bioremediation of contaminated environments through the removal, biodegradation, and transformation of harmful pollutants can be proposed. Therefore, this chapter focuses on the main extremophilic and extremotolerant yeasts that colonize extreme terrestrial ecosystems and their potential application in bioremediation processes.