| Co-Investigator(Kenkyū-buntansha) |
OGAWA Jun Kyoto Univ. Gradmate School of Agric., Assistant Prof, 農学研究科, 助手 (70281102)
KATAOKA Michihiko Kyoto Univ. Gradmate School of Agric., Associate Prof, 農学研究科, 助教授 (90252494)
KOBAYASHI Michihiko Tsukuba Univ. Div. of Appl. Biochem., Professor, 応用生物化学系, 教授 (70221976)
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| Research Abstract |
Fatty acid-desaturating systems in arachidonic acid-producing filamentous fungus, Mortierella alpina 1S-4, was investigated in gene level. Genomic DNAs and cDNAs of cytochrome b5 and NADPH-cytochrome b5 reductase, which involved in microsome electron transport system for fatty acid destruction, were cloned, and the gene products were expressed in Escherichia coli, and characterized in protein level.
Genomic DNA and cDNA of △9-desaturase which transform stearic acid to oleic acid, cDNAs of △12-and △6-desaturase which transform oleic acid to linoleic acid and linoleic acid to γ-linolenic acid, respectively, were cloned and their gene products were expressed in Aspergillus nigar.
The transformed Aspergillus with cDNAs of △9-, △12- and △6-desaturases accumulated oleic acid, linoleic acid and γ-linolenic acid, respectively.
Chemical mutation of M. alpina 1S-4 resulted in obtaining △6-desaturase defective mutant, ST66. This mutant accumulated linoleic acid and an unusual fatty acid 20 : 3△5, which is a △5-desaturation product of linoleic acid, was found.
Above all genetic and chemical breeding of fatty acid-producing fungi were attained.
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