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Identification and production of n−8 odd‐numbered polyunsaturated fatty acids by a Δ12 desaturation‐defective mutant of Mortierella alpina 1S‐4
Author(s) -
Zhang Shuo,
Sakuradani Eiji,
Shimizu Sakayu
Publication year - 2006
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/s11745-006-5011-z
Subject(s) - heptadecane , polyunsaturated fatty acid , chemistry , mycelium , mutant , fatty acid , biochemistry , food science , yeast , biosynthesis , stereochemistry , biology , organic chemistry , botany , gene
A mutant of Mortierella alpina , JT‐180, which is defective in its Δ12 desaturase activity but exhibits enhanced activities of Δ5 and Δ6 desaturases, produced a high proportion (up to 80%) of odd‐chain FA when grown on 3% n ‐heptadecane. Following growth of the mutant on n ‐heptadecane, three unusual odd‐chain fatty acyl residues were identified as 6,9‐heptadecadienoic acid (17∶2), 8,11‐nonadecadienoic acid (19∶2), and 5,8,11‐nonadecatrienoic acid (19∶3) by means of GC‐MS, MS‐MS, and NMR analysed. The mycelial contents of these FA reached 20.3, 3.6, and 5.8 ⧎/g dry mycelia, respectively, when it was cultivated in medium comprising 4% (vol/vol) n ‐heptadecane and 1% (wt/vol) yeast extract, pH 6.0, at 28°C for 7 d. The biosynthetic route (n−8 route) to 19∶3 was presumed to mimic the n−9 route to Mead acid (20∶3 n−9) in mammals: 17∶0→9–17∶1→6,9–17∶2→8,11–19∶2→5,8,11–19∶3.