The role and potential biotechnological applications of biosurfactants and bioemulsifiers produced by psychrophilic/psychrotolerant bacteria

The biosphere is subjected to low temperatures in both aquatic and terrestrial environments. Psychrophilic and psychrotolerant bacteria that colonize cold environments, such as Antarctica and Arctic continents, are able to survive in inhospitable conditions. This is attributed to some cold adaptations developed by these microorganisms over the years, such as the synthesis of carotenoid pigments, modification of membrane structure and production of biosurfactants (BS) and/or bioemulsifiers (BE). BS and BE are bioproducts produced by microorganisms that are less toxic than chemically synthesized surfactants. The physical and chemical properties of these substances make them applicable in different areas, such as bioremediation of contaminated areas, microbial enhanced oil recovery, pharmaceutical, cosmetics and food industries. Additionally, studies about BS and BE produced by psychrophiles and psychrotolerants are still very recent in relation to the studies carried out with mesophilic microorganisms and their products. This review aims to compile information on the mechanisms of adaptation of microorganisms in cold environments with a focus on the production of BS and BE and their potential biotechnological applications.