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United States Department of Agriculture

Agricultural Research Service

Title: Bioconversion of Alpha-Linolenic Acid by Clavibacter Sp. Ala2

Authors
item HOU, CHING
item Hosokawa, Masashi - VISITING SCIENTIST, JAPAN
item Weisleder, David

Submitted to: United States Japan Natural Resources Protein Panel
Publication Type: Proceedings
Publication Acceptance Date: October 15, 2002
Publication Date: December 1, 2002
Citation: HOU, C.T., HOSOKAWA, M., WEISLEDER, D. BIOCONVERSION OF ALPHA-LINOLENIC ACID BY CLAVIBACTER SP. ALA2. UNITED STATES JAPAN NATURAL RESOURCES PROTEIN PANEL. MONTEREY, CA. 2002. SECTION X. P. 1-11

Interpretive Summary: Previously, we discovered a new microbial strain ALA2 that produced seven new hydroxy fatty acid products from linoleic acid (a component of soybean oil). Hydroxy fatty acids are useful as starting materials for the synthesis of specialty chemicals, special military nylon, plastisizers, coatings and physiologically active agents. Recently, we expanded our substrate to other polyunsaturated fatty acids, such as alpha-linolenic acid (also a component of soybean oil). We found that strain ALA2 converted alpha-linlenlic acid to two novel hydroxy furanyl (five membered ring) fatty acids. Furanyl fatty acids are known anticancer drugs. The new products have great potential to be used as bioactive agents and raw materials for synthesis of specialty chemicals. Application of these products either as agents for anti-plant pathogenic fungi or raw material for synthesis of specialty chemicals will benefit U.S. farmers.

Technical Abstract: Microbial enzyme systems transform unsaturated fatty acids to functional substances. Previously, we reported that Clavibacter sp. ALA2 converted linoleic acid to unique cyclic fatty acids such as diepoxy bicyclic fatty acids (DEOA) and tetrahydrofuranyl fatty acids (THFA) as well as trihydroxy fatty acids (THOA). Now, we found that strain ALA2 converted alpha-linolenic acid (18:3, n-3) to novel tetrahydrofuranyl fatty acids, 13,16- dihydroxy- 12,15-epoxy-9(Z)-octadecenoic acid (13,16-dihydroxy-THFA) and 7,13,16-trihydroxy-12,15-epoxy-9(Z)- octadecenoic acid (7,13,16-trihydroxy-THFA). Chemical structures of these products were determined by GC/MS and proton and 13C NMR analyses. The optimum incubation temperature was 30 degrees C for the production of both THFAs. 13,16-Dihydroxy-THFA was detected after 2 days of incubation and reached 45 mg/50ml after 7 days of incubation. Whereas 7,13,16-trihydroxy-THFA was not detected after 2 days of incubation but reached 9 mg/50ml after 7 days of incubation. Total yield of both THFAs reached 67% after incubation of a-linolenic acid at 30 degrees C for 7 days. In our previous studies, we reported that Clavibacter sp. ALA2 oxidized C-16 and C-17 positions (saturated carbons) of linoleic acid into hydroxy groups. However, in this alpha-linolenic acid study, the bond oxidized at C-16 and C-17 carbons is a double bond. It seems that enzymes of strain ALA2 can insert hydroxy group into both saturated and unsaturated carbon chains. It also appears that strain ALA2 oxidized the C-12/C-13 and C-16/C-17 double bonds into dihydroxy groups first, and then converted them to hydroxy-THFAs. Physiological activity of these novel products is expected.

Last Modified: 9/10/2014
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