Production, purification, characterization, and applications of lipases

Lipases are secreted into the culture medium by many bacteria and fungi. They catalyse not only the hydrolysis but also the synthesis of long-chain acylglycerols. Important uses in biotechnology include their addition to detergents, the manufacture of food ingredients, pitch control in the pulp and paper industry, and biocatalysis of stereoselective transformations. This makes them the most widely used class of enzymes in organic chemistry. Immobilization in hydrophobic sol-gel matrices and in vitro evolution are promising novel approaches to increasing the stability or enantioselectivity, respectively, of lipases.

In order to exploit fully the biotechnological opportunities afforded by nonaqueous enzymology, the issue of often drastically diminished enzymatic activity in organic solvents compared with that in water must be addressed and resolved. Recent studies have made great strides towards elucidating causes of this phenomenon of activity loss. None of these causes is insurmountable; by designing strategies that systematically target them, enzymatic activity in organic solvents can be readily enhanced by multiple orders of magnitude and ultimately brought to the aqueous-like level.

Polyunsaturated fatty acids form a unique class of food constituents that show a wide range of functions in biological systems. Investigations over the past two decades have uncovered their roles and those of their eicosanoid metabolites, and have highlighted their homeostatic functions in mammals. A growing number of common human medical conditions are thought to be traceable to dysfunctions in the eicosanoid system, which could in turn be due to imbalances in the intake and/or metabolism of polyunsaturated fatty acids. This, together with medical advances, has spurred the introduction of biomedical products, nutritionals, fortified foods and health supplements.