LAUSR

Green leaf volatiles (GLVs) are C6- or C9-aldehydes, -alcohols and -esters which are released by plants in response to biotic or abiotic stresses. These compounds are named for their characteristic smell reminiscent of freshly mowed grass. This review focusses on GLVs and the two major pathway enzymes responsible for their formation: lipoxygenases (LOXs) and fatty acid hydroperoxide lyases (HPLs). LOXs catalyze the peroxidation of unsaturated fatty acids like linoleic and α-linolenic acid. Hydroperoxy fatty acids are further converted by HPLs into aldehydes and oxo-acids. In many industrial applications plant extracts have been used as LOX and HPL sources. However, these processes are limited by low enzyme concentration, stability and specificity. Alternatively, recombinant enzymes can be used as biocatalysts for GLV synthesis. The increasing number of well-characterized enzymes efficiently expressed by microbial hosts will foster the development of innovative biocatalytic processes for GLV production.