An extremozyme is an enzyme, often created by archaea, which are known prokaryotic extremophiles that can function under extreme environments. Examples of such are those in highly acidic/basic conditions, high/low temperatures, high salinity, or other factors, that would otherwise denature typical enzymes (e.g. catalase, rubisco, carbonic anhydrase). This feature makes these enzymes an interest to a variety of biotechnical applications in the energy, pharmaceutical, agricultural, environmental, food, health, and textile industries.
Since the 1960s, scientists knew that most enzymes have a range of functionality under different conditions. Due to their unique properties that allow catalytic reactions to occur in a more efficient nature, enzymes were sought after to use in harsh industrial chemical processes in the interest of profits and environmental protection. As time passed and demand called for higher product output, the harshness of the chemical processes continued to increase in severity in order to keep up with demands, which lead to the need for enzymes that could perform in conditions where their predecessors could not. In the 1980's, scientists found enzymes that could withstand abnormal conditions. Karl Stetter and his colleagues from the University of Regensburg, Germany discovered organisms that grew optimally at the boiling point of water (100 °C) or greater in geothermal sediments and the heated waters of the Italian Volcano Island. After this groundbreaking discovery, he went on to discover more than 20 genera of microbes that grew in nearly the same conditions, two of which are Thermotoga and Aquifex (bacteria, while the others were archaea. These discoveries intrigued the rest of the scientific world and within the next couple decades, countries such as Japan, Russia, France, and others searched for microbes that had the kind of extreme novel characteristics that Stetter's did.