F. Kähne, M. Buchhaupt, J. Schrader
Fatty aldehydes are an important group of fragrance and flavor compounds that are found in different fruits and flowers. A biotechnological synthesis of fatty aldehydes based onEscherichia coli cells expressing an α-dioxygenase (αDOX) from Oryza sativa (rice) is presented. α-Dioxygenases are the initial enzymes of α-oxidation in plants and oxidize long and medium-chain C n fatty acids to 2-hydroperoxy fatty acids. The latter are converted to Cn − 1 fatty aldehydes by spontaneous decarboxylation. Successful expression of αDOX in E. coliwas proven by an in vitro luciferase assay. Using resting cells of this recombinant E. colistrain, conversion of different fatty acids to the respective fatty aldehydes shortened by one carbon atom was demonstrated. The usage of Triton X 100 improves the conversion rate up to 1 g aldehyde per liter per hour. Easy reuse of the cells was demonstrated by performing a second biotransformation without any loss of biocatalytic activity.