NEW MICROBIAL SYSTEMS FOR UTILIZATION OF GLYCEROL AND PLANT LIPIDS
Location: National Center for Agricultural Utilization Research
Title: New Bioactive Fatty Acids
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: September 13, 2007
Publication Date: September 13, 2007
Citation: Hou, C.T. 2007. New bioactive fatty acids [abstract]. Asian Congress of Nutrition. S11-3. p. 35.
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 to12,13-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. 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 the ARS Culture Collection for the production of bioactive PUFAs such as dihomo-gama-linolenic acid (DGLA) and arachidonic acid. We found that higher dry cell mass and higher yield of ARA production are in the following order: Mortierella elongata, M. parvospora, M. zychae, M. humilis and M. multidivaricata. Although the fatty acid composition of ARA in M. alpina was the highest among strains screened, its dry cell weight and oil yield were low. The yield for DGLA production 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.