Lipid biomarkers and bacterial lipase activities as indicators of organic matter and bacterial dynamics in contrasted regimes at the DYFAMED site, NW Mediterranean

Bourguet, Nicolas; Goutx, Madeleine; Ghiglione, Jean-François; Pujo‐Pay, Mireille; Mével, Geneviève; Momzikoff, André; Mousseau, Laure; Guigue, Catherine; Garcia, Nicole; Raimbault, Patrick; Pete, Romain; Oriol, L.; Lefèvre, D.

doi:10.1016/j.dsr2.2008.11.034

Cited by 38 publications

(31 citation statements)

References 93 publications

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“…With the decline in chlorophyll concentration as the season advanced towards autumn, phospholipids, triacylglycerols and wax esters dominated the lipid material in the traps. Change in POM and DOM lipid composition from a glycolipidsdominated lipid pool, to a neutral (wax esters, triacylglycerols) and phospholipids-dominated lipid pool, has already been observed in ecosystems changing from micro-and or pico-phytoplankton to heterotrophs-dominated regimes (Smith et al, 1997;Goutx et al, 2000;Ghiglione et al, 2007;Bourguet et al, 2008). During DYNAPROC 2, a similar shift occurred in the suspended particles and dissolved matter .…”

Section: Links Between Production Regime and Fluxes; Comparison Withmentioning

confidence: 66%

Short-term changes in particulate fluxes measured by drifting sediment traps during end summer oligotrophic regime in the NW Mediterranean Sea

et al. 2009

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Abstract. Short-term changes in the flux of particulate matter were determined in the central north western Mediterranean Sea (near DYFAMED site) using drifting sediment traps at 200 m depth in the course of the DYNAPROC 2 cruise (14 September-17 October 2004). In this period of marked water column stratification, POC fluxes varied by an order of magnitude, in the range of 0.03-0.29 mgC m −2 h −1 over the month and showed very rapid and high variations. Particulate carbon export represented less than 5% of integrated primary production, suggesting that phytoplankton production was essentially sustained by internal recycling of organic matter and retained within the photic zone. While PON and POP fluxes paralleled one another, the elemental ratios POC/PON and POC/POP, varied widely over short-term periods. Values of these ratios generally higher than the conventional Redfield ratio, together with the very low chlorophyll a flux recorded in the traps (mean 0.017 µg m −2 h −1 ), and the high phaeopigment and acyl lipid hydrolysis metabolite concentrations of the settling material, indicated that the organic matter reaching 200 m depth was reworked (by grazing, fecal pellets production, degradation) and that algal sinking, dominated by nano-and picoplankton, made a small contribution to the downward flux. Over time, the relative abundance of individual lipid classes in organic matter (OM) changed from glycolipids-dominated to neutral (wax esters, triacylglycerols) and phospholipidsdominated, suggesting ecosystem maturation as well as rapidCorrespondence to: J. C. Marty (marty@obs-vlfr.fr) and continual exchanges between dissolved, suspended and sinking pools. Our most striking result was documenting the rapid change in fluxes of the various measured parameters. In the situation encountered here, with dominant regenerated production, a decrease of fluxes was noticed during windy periods (possibly through reduction of grazing). But fluxes increased as soon as calm conditions settle.

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Section: Links Between Production Regime and Fluxes; Comparison Withmentioning

confidence: 66%

Short-term changes in particulate fluxes measured by drifting sediment traps during end summer oligotrophic regime in the NW Mediterranean Sea

et al. 2009

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“…For higher concentrations of analog substrate used by some other authors (Sala et al, 2001: 200 µM;Zoppini et al, 2005: 125 µM), comparison is impossible due to multiple kinetics appearing according the range of concentration tested (Bogea et al, 2006). Bacterial lipase activities have received little attention and rate measurements in marine ecosystems are scarce (Bourguet et al, 2008) and, to our knowledge, inexistent in Mediterranean Sea. Furthermore, different lipases exhibit specific preferences for their triacylglycerol substrates, depending on chain length, optical and positional isomers, and the characteristics of the lipid/water interface.…”

Section: Bacterial Community Response To Nutrient Status Through Ectomentioning

confidence: 99%

Bottom up effects on bacterioplankton growth and composition during summer-autumn transition in the open NW Mediterranean Sea

et al. 2009

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Abstract. We examined the vertical and temporal dynamics of nutrients, ectoenzymatic activities under late summer-fall transition period (September-October 2004) in NW Mediterranean Sea in relation to temporal change in factors limiting bacterial production. The depth of the mixed layer (12.8±5.3 m) was extremely stable until the onset of the destratification period after 11 October, creating a zone where diffusion of nutrient from the much deeper phosphacline (69±12 m) and nitracline (50±8 m) was probably strongly limited. However after 1st October, a shallowing of nutriclines occured, particularly marked for nitracline. Hence, the nitrate to phosphate ratio within the mixed layer, although submitted to a high short term variability, shifted the last week of the cruise from 1.1±1.2 to 4.6±3.8, and nitrate increased by a factor 2 (0.092±0.049 µM). A corresponding switch from more than one limitation (PN) to P-only limitation of bacterial production was observed during the month as detected by enrichment bioassays. Differences in the identity of the limiting nutrient in surface (5 m: N and P at the beginning, strictly P at the end of the study) versus 80 m (labile carbon) influence greatly bacterial community structure shift between these two layers. The two communities (5 and 80 m) reacted rapidly (24 h) to changes in nutrient concentrations by drastic modification of total and active populaCorrespondence to: F. Van Wambeke (france.van-wambeke@univmed.fr) tion assemblages resulting in changes in activity. For bacterial production values less than 10 ng C l −1 h −1 (associated to deeper layers), aminopeptidase and lipase exhibited higher activity relative to production whereas phosphatase varied in the same proportions than BP on the range of activities tested. Our results illustrate the effect of bottom-up control on bacterial community structure and activities in the epipelagic NW Mediterranean Sea.

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“…Individual classes or groups of certain classes may be used to indicate the presence of certain types of organisms as well as their physiological state and activity [90]. Lipid classes can also be used to indicate sources of organic matter [91] including dissolved organic matter and hydrophobic contaminants [89,92]. Iatroscan-determined free fatty acids, alcohols, diacylglycerols, and monoacylglycerols in filtrates indicated seasonal, day/night, and depth differences in degradation in the North West Mediterranean Sea, while hydrocarbons showed the level of contamination [89,92].…”

Section: Molecular Biomarkersmentioning

confidence: 99%

Lipids in Marine Ecosystems

2013

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Lipids provide the densest form of energy in marine ecosystems. They are also a solvent and absorption carrier for organic contaminants and thus can be drivers of pollutant bioaccumulation. Among the lipids, certain essential fatty acids and sterols are considered to be important determinants of ecosystem health and stability. Fatty acids and sterols are also susceptible to oxidative damage leading to cytotoxicity and a decrease in membrane fluidity. The physical characteristics of biological membranes can be defended from the influence of changing temperature, pressure, or lipid peroxidation by altering the fatty acid and sterol composition of the lipid bilayer. Marine lipids are also a valuable tool to measure inputs, cycling, and loss of materials. Their heterogeneous nature makes them versatile biomarkers that are widely used in marine trophic studies, often with the help of multivariate statistics, to delineate carbon cycling and transfer of materials. Principal components analysis has a strong following as it permits data reduction and an objective interpretation of results, but several more sophisticated multivariate analyses which are more quantitative are emerging too. Integrating stable isotope and lipid data can facilitate the interpretation of both data sets and can provide a quantitative estimate of transfer across trophic levels.

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Lipid biomarkers and bacterial lipase activities as indicators of organic matter and bacterial dynamics in contrasted regimes at the DYFAMED site, NW Mediterranean

Cited by 38 publications

References 93 publications

Short-term changes in particulate fluxes measured by drifting sediment traps during end summer oligotrophic regime in the NW Mediterranean Sea

Short-term changes in particulate fluxes measured by drifting sediment traps during end summer oligotrophic regime in the NW Mediterranean Sea

Bottom up effects on bacterioplankton growth and composition during summer-autumn transition in the open NW Mediterranean Sea

Lipids in Marine Ecosystems

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