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Production of linolenic acid in yeast cells expressing an omega‐3 desaturase from tung ( Aleurites fordii )
Author(s) -
Dyer John M.,
Chapital Dorselyn C.,
Kuan JuiChang W.,
Shepherd Hurley S.,
Tang Fuqiang,
Pepperman Armand B.
Publication year - 2004
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/s11746-004-956-x
Subject(s) - linolenic acid , linoleic acid , biochemistry , yeast , biology , complementary dna , alpha linolenic acid , linum , polyunsaturated fatty acid , food science , fatty acid , botany , gene , docosahexaenoic acid
Tung oil is an industrial drying oil containing ca. 90% PUFA. We previously reported on enzymes required for the synthesis of linoleic (6% of FA) and eleostearic (80%) acids and here describe the cloning and functional analysis of an omega‐3 FA desaturase (FAD3) required for the synthesis of linolenic acid (1%). The tung FAD3 cDNA was identified by screening a tung seed cDNA library using the polymerase chain reaction and degenerate primers encoding conserved regions of the FAD3 enzyme family. Expression of this cDNA in yeast cells, cultured in the presence of linoleic acid, resulted in the synthesis and accumulation of linolenic acid, which accounted for up to 18% w/w of total cellular FA. Tung FAD3 activity was significantly affected by cultivation temperature, with the greatest amount of linolenic acid accumulating in yeast cells grown at 15°C. The amount of linolenic acid synthesized in yeast cells by tung FAD3 is ca . 10‐fold higher than that observed by expression of a rapeseed ( Brassica napus ) FAD3 in yeast, suggesting that tung FAD3 might be useful for biotechnological production of omega‐3 FA in transgenic organisms.