title: Occurrence of trans monounsaturated and polyunsaturated fatty acids in Colwellia psychrerythraea strain 34H.
abstract: Colwellia psychrerythraea strain 34H is an obligately psychrophilic bacterium that has been used as a model cold-adapted microorganism because of its psychrophilic growth profile, significant production of cold-active enzymes, and cryoprotectant extracellular polysaccharide substances. However, its fatty acid components, particularly trans unsaturated fatty acids and long-chain polyunsaturated fatty acids (LC-PUFAs), have not been fully investigated. In this study, we biochemically identified Δ9-trans hexadecenoic acid [16:1(9t)] and LC-PUFAs such as docosahexaenoic acid. These results are comparable with the fact that the strain 34H genome sequence includes pfa and cti genes that are responsible for the biosynthesis of LC-PUFAs and trans unsaturated fatty acids, respectively. Strain 34H cells grown under static conditions at 5 °C had higher levels of 16:1(9t) than those grown under shaken conditions, and this change was accompanied by an antiparallel decrease in the levels of Δ9-cis hexadecenoic acid [16:1(9c)], suggesting that the cis-to-trans isomerization reaction of 16:1(9c) is activated under static (microanaerobic) culture conditions, that is, the enzyme could be activated by the decreased dissolved oxygen concentration of cultures. On the other hand, the levels of LC-PUFAs were too low (less than 3% of the total), even for cells grown at 5 °C, to evaluate their cold-adaptive function in this bacterium.
authors.affiliation: Course in Molecular Biology, Division of Biosphere Science, Graduate School of Environmental Science, Hokkaido University, Kita-ku, Sapporo, Japan.
authors.forename: Mikako
authors.initials: M
authors.lastname: Hashimoto
authors.affiliation: Department of Food Science, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Japan.
authors.forename: Yoshitake
authors.initials: Y
authors.lastname: Orikasa
authors.affiliation: Cell-Free Science and Technology Research Center, Ehime University, Bunkyo-cho, Matsuyama, Japan.|Department of Chemistry, Faculty of Science, Ehime University, Bunkyo-cho, Matsuyama, Japan.
authors.forename: Hidenori
authors.initials: H
authors.lastname: Hayashi
authors.affiliation: Bioscience Group, National Institute of Polar Research, Midori-cho, Tachikawa, Tokyo, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Course in Ecological Genetics, Division of Biosphere Science, Graduate School of Environmental Science, Hokkaido University, Kita-ku, Sapporo, Japan.|Laboratory of Ecological Genetics, Section of Environmental Biology, Faculty of Environmental Earth Science, Hokkaido University, Kita-ku, Sapporo, Japan.
authors.forename: Kiyohito
authors.initials: K
authors.lastname: Yoshida
authors.affiliation: Course in Molecular Biology, Division of Biosphere Science, Graduate School of Environmental Science, Hokkaido University, Kita-ku, Sapporo, Japan.|Laboratory of Environmental Molecular Biology, Section of Environmental Biology, Faculty of Environmental Earth Science, Hokkaido University, Kita-ku, Sapporo, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Okuyama
mesh_terms: D034241:Alteromonadaceae / Q000737:chemistry* / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D001483:Base Sequence; D003080:Cold Temperature; D005229:Fatty Acids, Monounsaturated / Q000032:analysis*; D005231:Fatty Acids, Unsaturated / Q000032:analysis*; D007536:Isomerism; D011134:Polysaccharides; D044242:Trans Fatty Acids / Q000032:analysis*
chemical_list: D005229:Fatty Acids, Monounsaturated; D005231:Fatty Acids, Unsaturated; D011134:Polysaccharides; D044242:Trans Fatty Acids
keywords: Colwellia psychrerythraea strain 34H; Docosahexaenoic acid (DHA); Long-chain polyunsaturated fatty acid; Obligate psychrophile; trans Unsaturated fatty acid