1887

Abstract

Lipid metabolism was studied in 2-d-old liquid cultures of grown at 25 C. Under these conditions, oil accumulated to 0.5 g I with a ?-linolenic acid content (?18:3) of 60 mg I. The major labelled lipids in cultures incubated with [C]acetate were triacylglycerol (TAG), phosphatidylcholine (PC) and phosphatidylethanolamine (PE). The proportion of label declined in the phospholipids and increased in TAG with time. [C]18:1 and [C]18:2 rapidly appeared in PC and PE and later accumulated in [C]?18:3. TAG-synthesizing capacity was greatest in the microsomal membrane fraction, which accumulated high levels of phosphatidic acid in the presence of glycerol 3-phosphate and acyl-CoA substrates at pH 7.0. Further metabolism of phosphatidic acid to diacylglycerol and TAG was achieved by increasing the pH to 8.0. Lysophosphatidic acid:acyl-CoA acyltransferase (LPAAT) activity was particularly high and may have accounted for the rapid accumulation of phosphatidic acid in the membranes. The glycerol-3-phosphate:acyl-CoA acyltransferase (GPAAT) and LPAAT were non-specific for a range of saturated and unsaturated species of acyl-CoA although the GPAAT showed a marked selectivity for palmitoyl-CoA and the LPAAT for oleoyl- and linoleoyl-CoA. ?-Linolenic acid was detected at all three positions of -TAG and was particularly enriched at the -3 position. The preparation of active systems (microsomal membranes) capable of the complete biosynthetic pathway for TAG assembly may be valuable in understanding the assembly of oils in future transgenic applications.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-144-9-2639
1998-09-01
2024-04-26
Loading full text...

Full text loading...

/deliver/fulltext/micro/144/9/mic-144-9-2639.html?itemId=/content/journal/micro/10.1099/00221287-144-9-2639&mimeType=html&fmt=ahah

References

  1. Bligh E.G, Dyer W.J. 1959; A rapid method of total lipid extraction and purification.. Can J Biochem Physiol 37:911–917
    [Google Scholar]
  2. Brenner R.R. 1982; Nutritional and hormonal factors in-fluencing desaturation of essential fatty acids.. Prog Lipid Res 20:41–48
    [Google Scholar]
  3. Burnanova L., Rezanka T., Jandera A. 1990; Screening for strains of the genus Mortierella showing elevated production of highly unsaturated fatty acids.. Folia Microbiol 35:578–582
    [Google Scholar]
  4. Certik M., Sereke Berhan S., Sajbidor J. 1993; Lipid production and fatty acid composition of selected strains belonging to Mucorales.. Acta Biotechnol 13:193–196
    [Google Scholar]
  5. Christie W.W. 1982 Lipid Analysis Oxford: Pergamon Press;
    [Google Scholar]
  6. Griffiths G., Harwood J.L. 1991; The regulation of triacylglycerol biosynthesis in cocoa (Theobroma cacao L.).. Planta 184:279–284
    [Google Scholar]
  7. Griffiths G., Stobart A.K., Stymne S. 1985; The acylation of sn-glycerol 3-phosphate and the metabolism of phosphatidate in microsomal preparations from the developing cotyledons of safflower (Cartbamus tinctorius L.) seed.. Biochem J 230:379–388
    [Google Scholar]
  8. Griffiths G., Stymne S., Stobart A. K. 1988a; Delta-6 and delta-12 desaturase activities and phosphatidic acid formation in microsomal preparations from the developoing cotyledons of common borage {Borago officinalis).. Biochem J 252:641–647
    [Google Scholar]
  9. Griffiths G., Stymne S., Stobart A. K. 1988b; The utilisation of fatty-acid substrates in triacylglycerol biosynthesis by tissue-slices of developing safflower (Cartbamus tinctorius L.) and sunflower (Helianthus annuus L.) cotyledons.. Planta 173:309–316
    [Google Scholar]
  10. Griffiths G., Jones H.E., Eaton C.L., Stobart A.K. 1997; Effect of n-6 polyunsaturated fatty acids on growth and lipid composition of neoplastic and non-neoplastic canine prostate epithelial cell cultures.. Prostate 31:29–36
    [Google Scholar]
  11. Gurr M.J., Blades J., Appelby R.S., Smith C.G., Robinson M.P., Nichols B.W. 1974; Triglyceride biosynthesis and storage in whole seeds and oil bodies of Crambe abyssinica.. Eur J Biochem 43:281–290
    [Google Scholar]
  12. Harwood J.L. 1988; Fatty acid metabolism.. Annu Rev Plant Physiol Plant Mol Biol 39:101–138
    [Google Scholar]
  13. Holdsworth J.E., Ratledge C. 1991; Triacylglycerol synthesis in oleaginous yeast Candida curvata.. Lipids 26:111–118
    [Google Scholar]
  14. Hopewell R., Martin-Sanz P., Martin A., Saxton J., Brindley D.N. 1985; Regulation of the translocation of phosphatidate phosphohydrolase between the cytosol and the endoplasmic reticulum.. Biochem J 232:485–491
    [Google Scholar]
  15. Horrobin D.F. 1990 Omega-6 Essential Fatty Acids: Pathophysiology and Roles in Clinical Medicine New York: Wiley-Liss;
    [Google Scholar]
  16. Horrobin D.F. 1994 New Approaches to Cancer Treatment: Unsaturated Lipids and Photodynamic Therapy London: Churchill Communications International;
    [Google Scholar]
  17. Hosaka K., Yamashita S. 1984; Partial purification and properties of phosphatidate phosphatase in Saccharomyces cerevisiae.. Biochim Biophys Acta 796:102–109
    [Google Scholar]
  18. Ichihara K., Murota N., Fujii S. 1990; Intracellular trans-location of phosphatidate phosphatase in maturing safflower seeds: a possible mechanism of feedforward control of triacylglycerol synthesis by fatty acids.. Biochim Biophys Acta 1043:227–234
    [Google Scholar]
  19. Jackson F.M., Fraser T.C.M., Smith M.A., Lazarus C., Stobart A.K., Griffiths G. 1998; Biosynthesis of C18-polyunsaturated fatty acids in microsomal membrane preparations from the filamentous fungus, Mucor circinelloides.. Eur J Biochem 252/3:513–519
    [Google Scholar]
  20. Johnson D.R., Knoll L.J., Levin D.E., Gordon J.I. 1994; Saccharomyces cerevisiae contains four fatty acid activation (FAA) genes - an assessment of their role in regulating protein N-myristolation and cellular lipid metabolism.. J Cell Biol 127:751–762
    [Google Scholar]
  21. Kendrick A., Ratledge C. 1992; Desaturation of poly-unsaturated fatty acids in Mucor circinelloides and the involvement of a novel membrane-bound malic enzyme.. Eur J Biochem 209:667–673
    [Google Scholar]
  22. Meesters P.A.E.P., Eggink G. 1996; Isolation and characterization of a delta-9 fatty acid desaturase gene from the oleaginous yeast Cryptococcus curvatus CBS-570.. Yeast 12:723–730
    [Google Scholar]
  23. Murcott T., McNally T., Allen S., Fothergill-Gilmore L., Muirhead H. 1991; Purification, characterization and muta-genesis of highly expressed recombinant yeast pyruvate kinase.. Eur J Biochem 198:513–519
    [Google Scholar]
  24. Nakahara T., Yokochi T., Kamisaka Y., Suzuki O. 1992; Gamma-linolenic acid from the genus Mortierella. . In Industrial Applications of Single-cell Oils pp. 61–97 Kyle D.J., Ratledge C. Edited by Champaign, IL: American Oil Chemists̓ Society;
    [Google Scholar]
  25. Ratledge C. 1993; Single-cell oils-have they a biotechnological future?. Trends Biotechnol 11:278–284
    [Google Scholar]
  26. Sancholle M., Lösel D. 1995; Lipids in fungal biotechnology.. In The Mycota 11 Genetics and Biotechnology pp. 339–367 Kuck U. Edited by Berlin: Springer;
    [Google Scholar]
  27. Slabas A.R., Fawcett T., Griffiths G., Stobart A.K. 1993; Biochemistry and molecular biology of lipid biosynthesis in plants: potential for genetic manipulation.. In Biosynthesis and Manipulation of Plant Products 3 pp. 104–138 Grierson D. Edited by Oxford: Blackie Academic Press;
    [Google Scholar]
  28. Sprecher H., Luthria D.L., Mohammed B.S., Baykousheva M. 1995; Re-evaluation of the pathways for the biosynthesis of polyunsaturated fatty acids.. J Lipid Res 36:2471–2477
    [Google Scholar]
  29. Stobart A.K., Stymne S. 1985; The interconversion of diacyglycerol and phosphatidylcholine during triacylglycerol production in microsomal preparations of developing cotyledons of safflower (Carthamus tinctorius L.).. Biochem J 232:217–221
    [Google Scholar]
  30. Stobart A.K., Stymne S. 1990; Triacylglycerol biosynthesis.. Methods Plant Biochem, Lipids, Membr Photobiol 4:19–46
    [Google Scholar]
  31. Stymne S., Stobart A.K. 1984; Evidence for the reversibility of the acyl-CoA: lysophosphatidylcholine acyltransferase in microsomal preparations from developing safflower cotyledons and rat liver.. Biochem J 223:305–314
    [Google Scholar]
  32. Stymne S., Stobart A.K. 1985; Oil synthesis in vitro in microsomal membranes from developing cotyledons of Linum usitatissimum L.. Planta 164:101–104
    [Google Scholar]
  33. Stymne S., Stobart A.K. 1987; Triacylglycerol biosynthesis.. In The Biochemistry of Plants: a Comprehensive Treatise 9 pp. 175–214 Stumpf P.K. Edited by New York: Academic Press;
    [Google Scholar]
  34. Stymne S., Griffiths G., Stobart A.K. 1987; Desaturation of fatty acids on complex lipid substrates.. In The Metabolism, Structure and Function of Plant Lipids pp. 405–415 Stumpf P.K., Mudd J.B., Nes W.D. Edited by New York: Plenum;
    [Google Scholar]
  35. Suzuki O. 1988; Production of gamma-linolenic acid and its industrialization.. In Proceedings of the World Conference on Biotechnology for the Fats and Oils Industry pp. 110–116 Applewhite T.H. Edited by Champaign, IL: American Oil Chemists̓ Society;
    [Google Scholar]
  36. Zurier R.B. 1993; Fatty acids, inflammation! and immune responses.. Prostaglandins Leukot Essent Fatty Acids 48:57–62
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-144-9-2639
Loading
/content/journal/micro/10.1099/00221287-144-9-2639
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error