The first fluorogenic assay for detecting a Baeyer–Villigerase activity in microbial cells

The first fluorogenic assay allowing for detection of microbial enzymes able to perform Baeyer–Villiger oxidation is described. This is based on the use of 4-oxopentyl umbelliferyl ether 1 as a fluorogenic substrate. When Baeyer–Villigerases active against this test ketone are present in the selected whole cells, 1 is transformed into 3-hydroxypropyl umbelliferyl ether 3, which, in a subsequent step, releases the fluorescent product umbelliferone. Different microorganisms, known to be endowed with Baeyer–Villigerase activity, were assayed.