A FATTY-ACID ALPHA-KETOL, A PRODUCT OF THE PLANT LIPOXYGENASE PATHWAY, IS OXIDIZED TO 3(Z)-DODECENDIOIC ACID BY A BACTERIAL MONOOXYGENASE

The fatty acid alpha-ketol 13-hydroxy-12-oxo-9(Z)-octadecenoic acid (m ethyl ester) was incubated with a bacterial culture isolated from soil . The bacteria (tentatively identified as Ralstonia sp.) exhibited str ong monooxygenase activity growing on 2-tridecanone as sole source of carbon. They catalyzed a Baeyer-Villiger type of oxidation and convert ed the alpha-ketol to 3(Z)-dodecendioic acid. 3(Z)-Dodecendioic acid w as isolated from the incubation mixture and identified by comparison w ith an authentic reference compound. These findings offer both a physi ological role for alpha-ketol fatty acids in plant lipid hydroperoxide metabolism and new insights into an alternative biosynthetic pathway leading to traumatic acid (2(E)-dodecendioic acid). (C) 1997 Academic Press.