Lipases/esterases from extremophiles: main features and potential biotechnological applications - Chapter 13

Organisms living in extreme conditions are called extremophiles and are characterized by their ability of adaptation to the extreme conditions. According to the living conditions extremophiles are divided into different classes in thermophiles, psychrophiles, acidophiles, alkalophiles, halophiles and barophiles. The adaptation to extreme living conditions is observed at level of membrane, showing a different composition and types of lipids present if are compared to the mesophilc counterparts, and to the proteins, in terms of amino acids compositions and structural adaptation. Extremophiles produce biocatalysts unique in their type, which are highly specialized to perform the same reactions of the non-extremophilic counterparts but in extreme conditions. This allowed evaluating with a different perspective the possibilities of enzymes in industrial applications. Enzymes that are more versatile for biotechnological applications are hydrolases able to use water molecules to break chemical bounds. The more common hydrolases are esterases, lipases, peptidases nucleosidases, glycosidases and phosphatates. Here, we report in detail the superfamily of the esterases/lipases, which are enzymes specialized in the hydrolysis of esters/phosphoesters, and are fundamental in the metabolism of the cells. In particular we focused on enzymes from extremophiles, considering their particular structural characteristics, their specific amino acids composition, the processes in which are already used and other potential applications.