%0 Journal Article
%T Function and biotechnology of extremophilic enzymes in low water activity
%A Ram Karan
%A Melinda D Capes
%A Shiladitya DasSarma
%J Aquatic Biosystems
%D 2012
%I BioMed Central
%R 10.1186/2046-9063-8-4
%X Enzymes are nature's biocatalysts endowed with high catalytic power, remarkable substrate specificity, and ability to work under mild reaction conditions. These unique features led to enzyme applications in competitive bioprocesses as one of the foremost areas of biotechnology research. Most enzymes are active within a defined set of standard conditions close to what is considered normal for mesophilic terrestrial organisms. However, much of the biosphere is extreme by comparison (e.g. cold oceans and dry, salty deserts). Not surprisingly, the biosphere contains a very large number of extremophilic microorganisms with enzymes capable of functioning in unusual conditions [1,2].The discovery of thermostable DNA polymerases and their impact on research, medicine, and industry has underscored the potential benefits of enzymes from extreme environments [3]. Since that time, the biotechnological and industrial demand for stable enzymes functioning in harsh operational conditions has surged. A great deal of current effort is aimed at screening for new sources of novel enzymes capable of functioning in extreme conditions. The parallel development of sophisticated molecular biology tools has also enabled engineering of enzymes with novel properties using techniques such as site-directed mutagenesis, gene shuffling, directed evolution, chemical modifications and immobilization [4-6].Microorganisms which grow in extreme conditions have been an important source of stable and valuable enzymes [1,7,8]. Their enzymes, sometimes called "extremozymes", perform the same enzymatic functions as their non-extreme counterparts, but they can catalyze such reactions in conditions which inhibit or denature the less extreme forms. Interestingly, some of the enzymes derived from extremophiles display polyextremophilicity, i.e. stability and activity in more than one extreme condition, including high salt, alkaline pH, low temperature, and non-aqueous medium [2,9-11]. A basic understanding of
%K Extremophile
%K Extremozymes
%K Protein stability
%K Halophiles
%K Psychrophile
%K Cold activity
%K Organic solvent
%K Low temperature
%K High salinity
%K Biofuel
%K Bioenergy
%U http://www.aquaticbiosystems.org/content/8/1/4