Editorial: Enzymes from Extreme Environments

Enzymes are nature's biocatalysts and are equipped with high catalytic activity and remarkable substrate specificity. Enzymes catalyze the metabolic reactions necessary for all of life's processes and are able to catalyze reactions at much higher rates than would be possible without their action. The majority of enzymes are optimized to perform under physiological conditions or conditions considered normal for mesophilic, neutrophilic microorganisms (de Carvalho, 2011). However, a particular set of enzymes called " extremozymes " are adapted to perform the same enzymatic functions as their non-extreme counterparts, but with greater versatility and adaptability to harsh conditions. These enzymes are found in extremophiles, organisms that thrive in extreme physical and/or chemical conditions. Extremophiles are found in some of the most severe environments on Earth, including hydrothermal vents, hypersaline lakes and pools, alkaline soda lakes, dry deserts, cold oceans, and volcanic areas. Many industries are making efforts to move away from the use of harmful chemical processes. As a result, there is increasing biotechnological demand for enzymes that are stable and active under extreme conditions, such as those found in industrial processing. Over the past decade, screening, isolating, and optimizing the production of extremozymes has become one of the major areas of biotechnology research. The development of advanced, high-throughput screening and molecular biology techniques has facilitated the production of enzymes with extreme and optimized features. Despite these advances, however, the current enzyme toolbox is unable to meet industrial demands for processes requiring extreme conditions, such as high temperature, alkaline pH, low water activity, and resistance to metal ions. This Research Topic features some the latest progress in extremozyme research, with a focus on stability under extreme conditions and applicability to industrial processes. Beginning with the first use of an enzymatic preparation for a commercial application, Sarmiento et al. review the history of enzyme discovery and the development of the market need for robust extremozymes. The authors then focus on the characteristics of psychrophilic, thermophilic, and hyperthermophilic enzymes and discuss their current applications in research and industrial areas, the challenges of working with extremozymes, and highlight future trends in the discovery and production of extremozymes. Extremophilic enzymes play key roles in catalyzing commercially valuable chemical conversions without the production of toxic waste, which is the hallmark of traditional industrial chemical processes. These enzymes can be cloned and over-expressed, allowing for production of sufficient quantities for detailed biochemical and structural characterization and large-scale production …