Submitted to: Journal of Industrial Microbiology and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/9/2000
Publication Date: 3/1/2002
Citation: KIM, H., GARDNER, H.W., HOU, C.T. PRODUCTION OF ISOMERIC 9,10,13(9,12,13)-TRIHYDROXY-11E(10E)-OCTADECENOIC ACID FROM LINOLEIC ACID BY PSEUDOMONAS AERUGINOSA PR3. JOURNAL OF INDUSTRIAL MICROBIOLOGY AND BIOTECHNOLOGY. 2002. V. 30. P. 752-757. Interpretive Summary: Hydroxy fatty acids are important industrial materials derived from vegetable oils. Scientists in the National Center at Peoria have discovered hydroxy fatty acids produced from converting vegetable oils by microbial enzymes, which may be useful as starting materials for the synthesis of specialty chemicals, special military nylon, plastisizer, and anti-microbial agents. Our newly isolated microbial culture, strain PR3, produced a new compound, 7,10-dihydroxy-8(E)-octadecenoic acid from oleic acid, a component of soybean and corn oil. During our scale up production studies, we found that strain PR3 also produced isomeric trihydroxy unsaturated fatty acids from linoleic acid, another component of soybean oil. Structures of these new products resemble those of plant self-defense substance. Application of these hydroxy fatty acid products either as agents for anti-pathogenic fungi or as high volume starting materials for the synthesis of special military nylon will benefit the U.S. farmers.
Technical Abstract: Trihydroxy unsaturated fatty acids with 18 carbons have been reported as plant self-defense substances. Their production in nature are rare and mostly in plant systems. Previously, we reported that a new bacterial isolate, Pseudomonas aeruginosa PR3, converted oleic acid and ricinoleic acid to 7,10-dihydroxy-8(E)-octadecenoic acid and 7,10,12-trihydroxy- 8(E)-octadecenoic acid, respectively. Now we report that strain PR3 converted linoleic 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). Stereochemical analyses showed the presence of 16 different dia-stereomers, which is the maximum number possible. The optimum reaction temperature and pH for THOD production was 30C and 7.0, respectively. The optimum linoleic acid concentration was 10 mg/ml. The most effective single carbon and nitrogen sources were glucose and sodium glutamate, respectively. However, when the mixture of yeast extract (0.05%), (NH4)2HPO4 (0.2%), and NH4NO3 (0.1%) was used as nitrogen sources, THOD production was higher by 8.3% than the case of sodium glutamate. Maximum production of total THOD with 44% conversion of substrate was achieved at 72 hr of incubation after which THOD production remained in plateau up to 240 hr. THOD production and cell growth increased in parallel with glucose concentration up to 0.3% after which cell growth reached saturation and THOD production did not increase. These results suggested that THODs were not metabolized by strain PR3. This is the first report on microbial production of 9,10,13- and 9,12,13-THOD from linoleic acid.