Free radical oxidation (autoxidation) of alkenones and other lipids in cells of Emiliania huxleyi

Rontani, J.‐F.; Jameson, Ian; Christodoulou, Stéphane; Volkman, John K.

doi:10.1016/j.phytochem.2006.12.013

Cited by 26 publications

(13 citation statements)

References 51 publications

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“…These results were corroborated by the further finding of significant amounts of alkenediols arising from NaBH 4 -reduction of the corresponding hydroperoxyalkenones in cultures of E. huxleyi strain CS-57 grown under an atmosphere of air + 0.5% CO 2 (Rontani et al, 2007a) and more recently after incubation of a culture of the strain E. huxleyi TWP1 under darkness (Rontani, Unpublished results) (Fig. 14) both exhibiting an anomalously high unsaturation ratio It seems thus that autoxidation processes have the potential to affect alkenone distributions leading to a warm bias in estimates of palaeotemperatures derived from alkenone ratios in sediments.…”

Section: Wwwintechopencomsupporting

confidence: 54%

“…8). Compounds 22 and 23 (which are well specific markers of free radical oxidation) could be detected in particulate matter samples (Marchand et al, 2005) and E. huxleyi cells (Rontani et al, 2007a) attesting to the involvement of such processes in senescent phytoplanktonic cells. Free radical oxidation of chlorophyll phytyl chain appeared to be different in senescent cells of S. costatum (Rontani et al, 2003b).…”

Section: Chlorophyll Phytyl Side-chainmentioning

confidence: 79%

“…Large amounts of oxidation products of oleic acid could be detected in cells of E. huxleyi grown under an atmosphere of air + 0.5% CO 2 for 10 days (Rontani et al, 2007a). The presence (after NaBH 4 -reduction) of a high proportion of 11-hydroxyoctadec-cis-9-enoic (27) and 8-hydroxyoctadec-cis-9-enoic (29) acids (Fig.…”

Section: Unsaturated Fatty Acidsmentioning

confidence: 96%

“…Recently, autoxidative damages in cells of E. huxleyi strain CS-57 could be induced after incubation of this strain under an atmosphere of air + 0.5% CO 2 (Rontani et al, 2007a). The presence of additional CO 2 allowed: (i) to induce a stress that favoured oxidative damage and (ii) to decrease the pH of the culture medium releasing metal ions from EDTA complexes, which can act as catalysts of hydroperoxide homolysis.…”

Section: Free Radical Degradation (Autoxidation) Processes In Phototrmentioning

confidence: 99%

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Photo- and Free Radical-Mediated Oxidation of Lipid Components During the Senescence of Phototrophic Organisms

Rontani¹

2012

Senescence

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Section: Wwwintechopencomsupporting

confidence: 54%

Section: Chlorophyll Phytyl Side-chainmentioning

confidence: 79%

Section: Unsaturated Fatty Acidsmentioning

confidence: 96%

Section: Free Radical Degradation (Autoxidation) Processes In Phototrmentioning

confidence: 99%

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Photo- and Free Radical-Mediated Oxidation of Lipid Components During the Senescence of Phototrophic Organisms

Rontani¹

2012

Senescence

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“…In E. huxleyi, virus infection has been found to result in many modifications that may potentially cause, or be related to, changes in the lipid profile within the cell: these include disruption of photosynthetic processes, production of reactive oxygen species, reduction in enzyme activities, loss of membrane integrity and altered pigment composition (Evans et al 2006, Llewellyn et al 2007. Rontani et al (2007) recently showed that the fatty acid profile of E. huxleyi considerably changed under conditions of oxidative damage, which is likely during virus infection due to increased production of reactive oxygen species (Evans et al 2006). Furthermore, genome sequencing of the E. huxleyi-specific virus used in this study (strain EhV-86) revealed that it contains genes which encode some of the key proteins of the sphingolipid biosynthesis pathway, including the first ratelimiting enzyme, serine palmitoyl transferase (SPT) (Wilson et al 2005).…”

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confidence: 99%

Changes in Emiliania huxleyi fatty acid profiles during infection with E. huxleyi virus 86: physiological and ecological implications

Evans¹,

Pond²,

Wilson³

2009

Aquat. Microb. Ecol.

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Fatty acids profiles of Emiliania huxleyi strain CCMP1516 were determined in a virusinduced culture crash with E. huxleyi virus 86 (EhV-86). As cell numbers declined in the infected cultures due to virus lysis, a concomitant decrease in fatty acids was observed in the particulate fraction. The composition of fatty acids within infected E. huxleyi cells was restructured, with a shift from polyunsaturated to monounsaturated and saturated fatty acids (respective distributions changing from 70:10:20% at the start of the experiment to 44:24:32% at the final time point). In particular, decreases were seen in the major fatty acid 22:6(n-3) and in 18:5(n-3), whereas greatest increases were seen in 18:1(n-9) and 22:0. The increase in the amount and restructuring of the fatty acid pool in E. huxleyi was indicative of a combination of specific and non-specific effects of virus infection. Specific effects primarily included induction of metabolic pathways such as the synthesis of components involved in virus replication, the production of virions and signal transduction via sphingolipid biosynthesis. Non-specific effects due to stress were likely mediated by reactive oxygen species. Changes in the composition of virus-infected E. huxleyi are of significance to the food web since grazing on virus-infected blooms will decrease the amount of essential polyunsaturated fatty acids passed on to higher trophic levels. Consequently, this could decrease the overall productivity of marine ecosystems. KEY WORDS: Emiliania huxleyi · Virus · Fatty acids · Lipids · Virus infection · Oxidative stress Resale or republication not permitted without written consent of the publisherAquat Microb Ecol 55: [219][220][221][222][223][224][225][226][227][228] 2009 duces a suite of polyunsaturated long-chain alkenes, alkenones and alkenoates (Volkman et al. 1979, Marlowe et al. 1984, Patterson et al. 1994, Fidalgo et al. 1998. Interest in the lipid composition of this species stems predominantly from the use of its long-chain (C 37 -C 40 ) alkenones as paleo sea surface temperature proxies (Prahl & Wakeham 1987).Characterisation of fatty acids has revealed that Emiliania huxleyi cells are particularly rich in (n-3) polyunsaturated fatty acids (PUFA) (Volkman et al. 1989, Conte et al. 1994. A study of 8 geographically distinct strains revealed the major fatty acids during growth to be 14:0, 16:0, 18:1(n-9), 18:4(n-3), 18:5(n-3) and 22:6(n-3), with the last being the most abundant during exponential growth and the stationary phase (Pond & Harris 1996). Within E. huxleyi, alkenones and alkenoates have been found to be associated with internal structures such as the endoplasmic reticulum and the coccolith-producing compartment, and it was suggested that these were membrane-unbound lipids. In contrast, fatty acids typical of membrane lipids are found in the chloroplast thylakoids and in the Golgi and plasma membranes (Sawada & Shiraiwa 2004). More recent studies indicate that E. huxleyi packages its neutral lipids into cytoplasmic vesicles or...

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Submicron NE Atlantic marine aerosol chemical composition and abundance: Seasonal trends and air mass categorization

Ovadnevaitė

Čeburnis

Leinert

et al. 2014

J. Geophys. Res. Atmos.

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Three years of continuous Aerosol Mass Spectrometry measurements at the Mace Head GlobalAtmosphere Watch research station revealed seasonal patterns in the chemical composition of submicron NE Atlantic marine aerosol as well as distinct chemical signatures associated with marine air masses of different origin (i.e., polar, Arctic, or tropical). Concentrations of secondary inorganic aerosol species and both primary and secondary organic compounds were closely related to oceanic biological activity and ranged from low median mass concentrations during winter to high median values during summer as follows: 0.025-0.9 μg m ). Maritime polar air masses typically featured the highest concentrations of sea salt and marine organics, particularly enhanced under primary organic plumes during periods of high biological activity. MSA and nss-sulfate were more prominent in tropical air masses. The oxidation of organic matter increased with increasing ozone concentration and wintertime (low biological activity) organic matter displayed a different fragmentation pattern from that of summertime organic compounds.

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Free radical oxidation (autoxidation) of alkenones and other lipids in cells of Emiliania huxleyi

Cited by 26 publications

References 51 publications

Photo- and Free Radical-Mediated Oxidation of Lipid Components During the Senescence of Phototrophic Organisms

Photo- and Free Radical-Mediated Oxidation of Lipid Components During the Senescence of Phototrophic Organisms

Changes in Emiliania huxleyi fatty acid profiles during infection with E. huxleyi virus 86: physiological and ecological implications

Submicron NE Atlantic marine aerosol chemical composition and abundance: Seasonal trends and air mass categorization

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