Production of isomeric 9,10,13 (9,12,13)-trihydroxy-11E (10E)-octadecenoicacid from linoleic acid by Pseudomonas aeruginosa PR3

Trihydroxy unsaturated fatty acids with 18 carbons have been reported as pl ant self-defense substances. Their production in nature is rare and is foun d mainly in plant systems. Previously, we reported that a new bacterial iso late, Pseudomonas aeruginosa PR3, converted oleic acid and ricinoleic acid to 7,10-dihydroxy-8(E)-octadecenoic acid and 7,10,12-trihydroxy-8(E) -octad ecenoic acid, respectively. Here we report that strain PR3 converted linole ic acid to two compounds: 9,10,13-trihydroxy-11 (E)-octadecenoic acid (9,10 ,13-THOD) and 9,12,13-trihydroxy-10(E)-octadecenoic acid (9,12,13-THOD). St ereochemical analyses showed the presence of 16 different diastereomers the maximum number possible. The optimum reaction temperature and pH for THOD production were 30 degrees C and 7.0, respectively. The optimum linoleic ac id concentration was 10 mg/ml. The most effective single carbon and nitroge n sources were glucose and sodium glutamate, respectively. However, when a mixture of yeast extract (0.05%), (NH4)(2)HPO4 (0.2%), and NH4NO3 (0.1%) wa s used as the nitrogen source, THOD production was higher by 8.3% than when sodium glutamate was the nitrogen source. Maximum production of total THOD with 44% conversion of substrate was achieved at 72 h of incubation, after which THOD production plateaued up to 240 h, THOD production and cell grow th increased in parallel with glucose concentration up to 0.3%, after which cell growth reached its maximum and THOD production did not increase. Thes e results suggested that THODs were not metabolized by strain PR3, This is the first report of microbial production of 9,10,13- and 9,12,13-THOD from linoleic acid.