Microbial Kinetic Resolution of Aroma Compounds Using Solid-State Fermentation

A novel microbial approach to the production of enantiomerically enriched and pure aroma compounds based on kinetic resolution via solid-state fermentation is proposed. Twenty-five filamentous fungi were screened for lipase activity and enantioselective hydrolysis of a volatile racemic ester (1-phenylethyl acetate (1)) and several racemic lactones (trans and cis whisky lactones (4, 5), γ-decalactone (7), δ-decalactone (8), (cis-3a,4,7,7a-tetrahydro-1(3H)-isobenzofuranone) (9)). Solid-state fermentation was conducted with linseed and rapeseed cakes. Kinetic resolution afforded enantiomerically enriched products with high enantiomeric excesses (ee = 82–99%). The results highlight the potential economic value of solid-state fermentation using agroindustrial side-stream feedstocks as an alternative to more expensive processes conducted in submerged fermentation.