Enzymes as biocatalysts in the modification of natural lipids

Though designed by nature tot effect hydrolysis of lipids, lipases can, und er appropriate reaction conditions, promote ester formation through reactio n of acids and alcohols (esterification) or of esters with acids (acidolysi s), alcohols (alcoholysis), or other esters (interesterification). Compared with chemical processes already carried out on an industrial scale enzymic reactions occur under milder (and 'greener') conditions though they may ta ke longer. Of greater significance is the specificity shown by the enzymes which permits the formation of lipid derivatives not easily prepared by con ventional laboratory procedures. This review describes the lipases and their various specificities and repor ts on their use in hydrolysis and in the production of phospholipids, fatty acids, alkyl esters, mono- and di-acylglycerols, triacylglycerols, other e sters, and amides. Some of these have already led to marketable products bu t for the most part the full potential of these reactions has yet to be rea lised. The reactions of other enzymes promoting interesting reactions at un saturated centres are also described. (C) 1999 Society of Chemical Industry .