Halophilic, Acidophilic, and Haloacidophilic Prokaryotes

Abstract

During Earth's evolution, accompanied by geophysical and climatic changes, a number of ecosystems have been formed which differ by the broad variety of physicochemical and biological factors composing our environment (Pikuta et al., 2007). Traditionally, extreme conditions can refer to physical extremes such as temperature, pressure, and radiation, but also to geochemical extremes such as desiccation, salinity, pH, and toxins (van den Burg, 2003). Many microorganisms survive under physically and geochemically extreme conditions, and these are termed as extremophiles, including thermophilic, psychrophilic, piezophilic, radioresistant, xerophilic, halophilic, acidophilic, alkaliphilic, metallotolerant, toxitolerant, and oligotrophic. This chapter deals with polyextremophile organisms that are both halophilic and acidophilic.