Confirmation of a new food chain utilizing geothermal energy: Unusual fatty acids of a deep-sea bivalve, Calyptogena phaseoliformis

AbstractSponges produce distinct fatty acids (FAs) that (potentially) can be used as chemotaxonomic and ecological biomarkers to study endosymbiont-host interactions and the functional ecology of sponges. Here, we present FA profiles of five common habitat-building deep-sea sponges (class Demospongiae, order Tetractinellida), which are classified as high microbial abundance (HMA) species. Geodia hentscheli, G. parva, G. atlantica, G. barretti, and Stelletta rhaphidiophora were collected from boreal and Arctic sponge grounds in the North-Atlantic Ocean. Bacterial FAs dominated in all five species and particularly isomeric mixtures of mid-chain branched FAs (MBFAs, 8- and 9-Me-C16:0 and 10 and 11-Me-C18:0) were found in high abundance (together ≥ 20% of total FAs) aside more common bacterial markers. In addition, the sponges produced long-chain linear, mid- and a(i)-branched unsaturated FAs (LCFAs) with a chain length of 24‒28 C atoms and had predominantly the typical Δ5,9 unsaturation, although also Δ9,19 and (yet undescribed) Δ11,21 unsaturations were identified. G. parva and S. rhaphidiophora each produced distinct LCFAs, while G. atlantica, G. barretti, and G. hentscheli produced similar LCFAs, but in different ratios. The different bacterial precursors varied in carbon isotopic composition (δ13C), with MBFAs being more enriched compared to other bacterial (linear and a(i)-branched) FAs. We propose biosynthetic pathways for different LCFAs from their bacterial precursors, that are consistent with small isotopic differences found in LCFAs. Indeed, FA profiles of deep-sea sponges can serve as chemotaxonomic markers and support the conception that sponges acquire building blocks from their endosymbiotic bacteria.

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Production and Accumulation of Unusual Fatty Acids in Plant Tissues

Biocatalysis and Biomolecular Engineering ◽

10.1002/9780470608524.ch3 ◽

2010 ◽

pp. 43-56

Author(s):

D. Hildebrand ◽

J. R. Thoguru ◽

S. Rao ◽

R. Li ◽

T. Hatanaka

Keyword(s):

Fatty Acids ◽

Plant Tissues ◽

Unusual Fatty Acids

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Lipids: Fatty Acids

Chemical Biomarkers in Aquatic Ecosystems ◽

10.23943/princeton/9780691134147.003.0008 ◽

2011 ◽

Author(s):

Thomas S. Bianchi ◽

Elizabeth A. Canuel

Keyword(s):

Fatty Acids ◽

Polyunsaturated Fatty Acids ◽

Deep Sea ◽

Saturated Fatty Acids ◽

Relative Proportion ◽

Aquatic Organisms ◽

Building Blocks ◽

Deep Sea Bacteria ◽

Total Fatty Acids ◽

Fatty Acid Biomarkers

This chapter discusses fatty acids, the building blocks of lipids, which represent a significant fraction of the total lipid pool in aquatic organisms. It explores how chain length and levels of unsaturation (number of double bonds) have been shown to be correlated to decomposition, indicating a pre- and postdepositional selective loss of short-chain and polyunsaturated fatty acids. In contrast, saturated fatty acids are more stable and typically increase in relative proportion to total fatty acids with increasing sediment depth. Polyunsaturated fatty acids (PUFAs) are predominantly used as proxies for the presence of “fresh” algal sources, although some PUFAs also occur in vascular plants and deep-sea bacteria. Thus, these biomarkers represent a very diverse group of compounds present in aquatic systems. The numerous applications of fatty acid biomarkers to identifying the sources of organic matter in lakes, rivers, estuaries, and marine ecosystems are discussed.

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Production of unusual fatty acids in rapeseed

Oléagineux Corps gras Lipides ◽

10.1051/ocl.2002.0024 ◽

2002 ◽

Vol 9 (1) ◽

pp. 24-30 ◽

Cited By ~ 4

Author(s):

Thomas Roscoe ◽

Sylvie Maisonneuve ◽

Michel Delseny

Keyword(s):

Fatty Acids ◽

Unusual Fatty Acids

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Monounsaturated but Not Polyunsaturated Fatty Acids Are Required for Growth of the Deep-Sea BacteriumPhotobacterium profundum SS9 at High Pressure and Low Temperature

Applied and Environmental Microbiology ◽

10.1128/aem.65.4.1710-1720.1999 ◽

1999 ◽

Vol 65 (4) ◽

pp. 1710-1720 ◽

Cited By ~ 154

Author(s):

Eric E. Allen ◽

Daniel Facciotti ◽

Douglas H. Bartlett

Keyword(s):

Fatty Acids ◽

High Pressure ◽

Fatty Acid ◽

Low Temperature ◽

Mutant Strain ◽

Deep Sea ◽

High Pressures ◽

Unsaturated Fatty Acids ◽

Temperature Sensitive ◽

Pressure Sensitive

ABSTRACT There is considerable evidence correlating the production of increased proportions of membrane unsaturated fatty acids (UFAs) with bacterial growth at low temperatures or high pressures. In order to assess the importance of UFAs to microbial growth under these conditions, the effects of conditions altering UFA levels in the psychrotolerant piezophilic deep-sea bacterium Photobacterium profundum SS9 were investigated. The fatty acids produced byP. profundum SS9 grown at various temperatures and pressures were characterized, and differences in fatty acid composition as a function of phase growth, and between inner and outer membranes, were noted. P. profundum SS9 was found to exhibit enhanced proportions of both monounsaturated (MUFAs) and polyunsaturated (PUFAs) fatty acids when grown at a decreased temperature or elevated pressure. Treatment of cells with cerulenin inhibited MUFA but not PUFA synthesis and led to a decreased growth rate and yield at low temperature and high pressure. In addition, oleic acid-auxotrophic mutants were isolated. One of these mutants, strain EA3, was deficient in the production of MUFAs and was both low-temperature sensitive and high-pressure sensitive in the absence of exogenous 18:1 fatty acid. Another mutant, strain EA2, produced little MUFA but elevated levels of the PUFA species eicosapentaenoic acid (EPA; 20:5n-3). This mutant grew slowly but was not low-temperature sensitive or high-pressure sensitive. Finally, reverse genetics was employed to construct a mutant unable to produce EPA. This mutant, strain EA10, was also not low-temperature sensitive or high-pressure sensitive. The significance of these results to the understanding of the role of UFAs in growth under low-temperature or high-pressure conditions is discussed.

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