Author
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Hou, Ching |
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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 11/30/2007 Publication Date: 11/30/2007 Citation: Hou, C.T. 2007. New bioactive fatty acids from vegetable oils and new uses of bioglycerin [abstract]. International Symposium on Biocatalysis and Biotechnology. A-4. p. 25. Interpretive Summary: Technical Abstract: Many oxygenated fatty acids are bioactive compounds. Nocardia cholesterolicum and Flavobacterium DS5 convert oleic acid to 10 hydroxy stearic acid and linoleic acid to 10-hydroxy-12(Z)-octadecanoic acid. Pseudomonas aeruginosa PR3 converts oleic acid to new compounds, 7,10-dihydroxy-8(E)-octadecenoic acid through 10-hydroxy-8-octadecenoic acid, and racinoleic acid to 7,10,12-trihydroxy-8-octadecenoic acid. Bacillus megaterium ALA2 converted n-6 and n-3 PUFAs to many new oxygenated fatty acids. For example: linoleic acid was converted to 12,13-epoxy-9-octadecenoic acid and then to 12,13-dihydroxy-9-octadecenoic acid (12,13-DHOA). From here, there are two bioconversion pathways. The major pathway is: 12,13-DHOA -> 12,13,17-trihydroxy-9(S)-octadecenoic acid (THOA) -> 12,17;13,17-diepoxy-16-hydroxy-9(Z)-octadecenoic acid (DEBOA) -> 7-hydroxy-DEBOA. The minor pathway is: 12,13-DHOA -> 12,13,16-THOA -> 12-hydroxy-13,16-epoxy-9(Z)-octadecenoic acid. 12,13,17-THOA has anti-plant pathogenic fungal activity. The tetrahydrofuranyl moiety is known in anti-cancer drugs. Strain ALA2 also converts other n-3 and n-6 PUFAs such as EPA, DHA and ARA to many new oxygenated unsaturated fatty acid products. All these new products have high potential for biomedical applications. We also screened 12 Mortierella fungal strains from ARS Culture Collection for the production of bioactive PUFAs such as dihomo-gama-linolenic acid (DGLA, n-6 PUFA; C18:3), and arachidonic acid (n-3 PUFA, C20:4). We found that higher dry cell mass and higher yield of arachidonic acid are in the following order: Mortierella elongata, M. parvospora, M. zychae, M. humilis and M. multidivaricata. Although the fatty acid composition of arachidonic acid in M. alpina was the highest among strains screened, its dry cell weight and oil yield were low. The yield for DGLA is in the following order: M. hygrophila, M. epigama, and M. nantahalensis. We also found that glycerol, a co-product of biodiesel production from soybean oil, can be used as substrate to produce these bioactive fatty acids. |
