André Mariotti's research while affiliated with French National Centre for Scientific Research and other places

Publications (265)

Data
Scanning Electron Microscopy of the sand grains surface at 0, 1, 2, and 3 days of incubation.
Data
Proportion of CRing in the CO2 evolved during the 10 day incubation of C.necator JMP134 in the control (white circles) and sand (gray circles) microcosms. Error bars correspond to the standard deviation calculated for 3 replicates. Dash line represents the proportion of CRing in the substrate (2,4-D) used.
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Evolution of the cyclopropyl/precursor ratio (cycC17:0 + cycC19:0/C16:1ω9c + C18:1ω9c) with time.
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Example of chromatograms (GC-FID) of the lipid fraction obtained from the sand samples at each sampling date. 2,4-D but no metabolites were detected. The other peaks corresponded to the bacterial fatty acids.
Data
Composition (molar percentage) of C.necator JMP134 FAME profiles in the control (upper) and sand (lower) samples at each sampling date. Error bars correspond to the standard deviation calculated for 3 replicates.
Data
Proportion of CRing in each FAME of C.necator JMP134 for the control (A) and sand (B) microcosms at each sampling date. Error bars correspond to the standard deviation calculated for 3 replicates. The gray line represents the proportion of CRing in the substrate (2,4-D) used.
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The development of bacterial biofilms in natural environments may alter important functions, such as pollutant bioremediation by modifying both the degraders' physiology and/or interactions within the matrix. The present study focuses on the influence of biofilm formation on the metabolism of a pesticide, 2,4-dichlorophenoxyacetic acid (2,4-D), by...
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We thank Castellano and David for their insightful comments (1) on our paper (2), in which they point out that short-term changes in land use and agricultural management can lead to rapid reductions in nitrate leaching from agricultural systems. We fully agree with Castellano and David that in diversified cropping system, this N distribution may be...
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Increasing diffuse nitrate loading of surface waters and groundwater has emerged as a major problem in many agricultural areas of the world, resulting in contamination of drinking water resources in aquifers as well as eutrophication of freshwaters and coastal marine ecosystems. Although empirical correlations between application rates of N fertili...
Article
Environmental context The greenhouse gas nitrous oxide is produced by bacteria and emitted from terrestrial and aquatic environments; the origin of this compound can be determined by its 15N intramolecular distribution (site preference). The site preference of nitrous oxide was characterised experimentally in bacterial denitrifying communities unde...
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Numerous greenhouse gas studies have focused on carbon dioxide (CO2), whereas nitrous oxide (N2O) also plays a major role in global warming. Indeed, while nitrous oxide is 1000 times less concentrated than CO2 in the atmosphere, it is 300 times more efficient in terms of global warming potential. In addition, its atmospheric concentration increases...
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The soil microbial biomass (SMB) is known to participate in key soil processes such as the decomposition of soil organic matter (SOM). However, its contribution to the isotopic composition of the SOM is not clear yet. Shifts in the 13C and 15N natural abundances of the SMB and SOM fractions (mineralised, water soluble and non-extractable) were inve...
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Combining lipid biomarker profiling with stable isotope probing (SIP) is a powerful technique for studying specific microbial populations responsible for the degradation of organic pollutants in various natural environments. However, the presence of other easily degradable substrates may induce significant physiological changes by altering both the...
Article
Vegetation fires profoundly alter the C cycle of terrestrial ecosystems, notably through the potential formation of highly stable pyrogenic structures. Fire-induced changes in the structure of organic matter (OM) have been studied mainly under controlled laboratory conditions. The objective of this work was to characterise changes in OM chemistry o...
Article
The biodegradation of nonextractable residues (NER) of pesticides in soil is still poorly understood. The aim of this study was to evaluate the influence of NER ageing and fresh soil addition on the microbial communities responsible for their mineralisation. Soil containing either 15 or 90-day-old NER of (13)C-2,4-D (NER15 and NER90, respectively)...
Article
Stable Isotope Probing (SIP) is a powerful tool for analysing the fate of pesticides in soil. Together with FAME (Fatty Acid Methyl Esters), it can help identify biodegradation pathways and recycling into the microbial biomass. The fate of ring-labelled 13C-2,4-dichlorophenoxyacetic acid or 2,4-D (C2,4-D) was determined in soil during a 6-month inc...
Article
The biodegradation of nonextractable residues (NER) of pesticides in soil is still poorly understood. The aim of this study was to evaluate the influence of NER ageing and fresh soil addition on the microbial communities responsible for their mineralisation. Soil containing either 15 or 90-day-old NER of 13C-2,4-D (NER15 and NER90, respectively) wa...
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Recent in situ13C studies suggest that lignin is not stabilised in soil in its polymerised form. However, the fate of its transformation products remains unknown. The objective of the present research was to provide the first comprehensive picture of the fate of lignin-derived C across its transformations processes: (1) C remaining as undecomposed...
Article
Restoration of the nitrogen cycle is an important step in the recovery of an ecosystem after mining. Carbon and nitrogen in rehabilitated lignite containing mine soils can be derived from plant material as well as from lignite inherent to the parent substrate. We assessed the use elemental and stable carbon and nitrogen isotope measurements to trac...
Article
The use of stable isotope probing of fatty acid methyl esters (FAME-SIP) is a powerful tool to study the microorganisms involved in xenobiotic biodegradation in soil. Nevertheless, it is important to determine how representative these molecules are of microorganisms both qualitatively and quantitatively. Using Cupriavidus necator JMP134 as a simple...
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Fire profoundly modifies the terrestrial C cycle of about 40% of the Earth’s land surface. The immediate effect of fire is that of a net loss of C as CO2 gas and soot particles to the atmosphere. Nevertheless, a proportion of the ecosystem biomass is converted into charcoal, which contains highly recalcitrant molecular structures that contribute to...
Article
The refractory (insoluble and resistant to drastic laboratory hydrolyses) organic macromolecular material (ROM), isolated from a sandy spodosol from Cestas (Landes de Gascogne, France), was examined via a combination of isotopic (δ13C measurements), spectroscopic (FTIR and solid-state 13C NMR) and pyrolytic (conventional pyrolysis and thermally ass...
Chapter
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Soils of tropical regions account for ca. 30 % of the terrestrial organic carbon pool. Present-day fires, deforestation and land use changes enhance soil erosion and soil organic matter mineralization, increasing as much the CO2 flux to the atmosphere and reducing the efficiency of organic carbon storage in soils. This chapter presents the results...
Article
The effect of demineralisation using hydrofluoric acid (HF) treatment on the elemental, isotopic and chemical composition of organic matter with increasing degree of humification was examined using four horizons of a forest humus profile. The aim was to determine whether HF treatment alters pristine organic matter or not. The conceptual approach in...
Article
Black carbon (BC) was isolated from sandy soils of a pine forest reference plot and an adjacent plot used for maize cropping since forest clearing 22 years ago. This was performed by: (i) isolation of a refractory organic macromolecular fraction (ROM) using strong hydrolysis followed by chemo-thermal oxidation (CTO) and (ii) direct hand-picking of...
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Lignin has long been suspected to be a major source of stable carbon in soils, notably because of the recalcitrant nature of its polyphenolic structure relative to other families of plant molecules. However, lignin turnover studies have produced conflicting results, most of them suggesting that large proportions of plant-residue lignin decompose wi...
Article
Three methods of cultivation, conventional tillage (CT), superficial tillage (ST) and no-tillage (NT), were applied for 17 years to continuous maize. Their effect on soil organic carbon content was investigated through measurements of carbon and 13C/12C ratios, using the natural difference in 13C content between C3 plants and maize, which is a C4 p...
Article
Lignin transformation and decomposition products are generally considered a major source of stable soil organic matter (SOM). Nevertheless this process remains poorly understood in part because lignin is a heterogeneous biopolymer composed of several types of phenol monomers, which potentially display specific and contrasting decomposition kinetics...
Article
The mine soils and sediments in the Lusatian open-cast lignite mining district (Germany) contain substantial amounts of lignite in addition to recent organic matter derived from plant litter. Knowledge of organic matter (OM) types and their transformation in mine soils and sediments is essential for the evaluation of ecosystem functioning in this r...
Article
Double-shot pyrolysis was performed on the insoluble, non-hydrolysable, macromolecular material isolated from a sandy forest soil of Cestas (Landes de Gascogne, France). Analysis of the pyrolysates showed conspicuous differences between the first and the second shot regarding the nature and/or the distribution of the numerous products generated. Th...
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Downstream from metropolitan Paris (France), a large amount of ammonium is discharged into the Seine River by the effluents of the wastewater treatment plant at Achères. To assess the extent of nitrification and denitrification in the water column, concentrations and isotopic compositions of ammonium (δ15N–NH4+) and nitrate (δ15N–NO3−, δ18O–NO3−) w...
Article
Lipid analysis was performed for three particle size fractions (i.e., sand-, silt- and clay-sized) isolated from a sandy spodosol of the Cestas cultivation sequence (Landes de Gascogne, France). The forest was cleared 22 years ago and since then it has been continuously used for maize cropping. Lipid identification was carried out before and after...
Article
In this study we investigated the quantitative and qualitative aspects of soil organic matter (SOM) losses caused by water erosion within a small catchment in Northern Laos, under steep slopes and slash and burn agriculture. The soils in the region have a high contribution of black carbon to soil organic matter and high erosion rates. The aim of th...
Article
Tropical soils are generally depleted in organic carbon (OC) due to environmental conditions favouring decomposition and mineralisation of soil organic matter (SOM). In Northern Laos, sloping soils are subjected to slash and burn agriculture, which leads to production of black carbon (BC), a stable SOM fraction. BC may directly influence the quanti...
Article
Downstream from metropolitan Paris (France), a large amount of ammonium is discharged into the Seine River by the effluents of the wastewater treatment plant at Achè res. To assess the extent of nitrification and denitrification in the water column , concentrations and isotopic compositions of ammonium (d 15 N–NH 4 +) and nitrate (d 15 N–NO 3) , d...
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We isolated the non-hydrolysable macromolecular organic fraction (insoluble fraction resistant to drastic laboratory hydrolyses) from a temperate, loamy, forest soil (Lacadée, France) and from the soil of an adjacent plot cleared 35 years ago and continuously cropped with maize. The quantitative, morphological (light, scanning and transmission elec...
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Plant residues incorporated into soils are subjected to contrasted stabilization and biodegradation processes and may contribute to pools of soil organic matter (SOM) displaying different turnover times. Little is known about the relationship between the chemical structure of plant macromolecules and their long-term turnover in soils. Our research...
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In the Congo, near Pointe-Noire, Pinus and Eucalyptus were planted on the savanna for 30 years. We have characterized the effects of this change on land-use on the composition of carbohydrates in whole soil and particle-size fractions of the soil. Carbohydrates represent variable proportions of the total soil organic carbon (TOC) of various particl...
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The composition of the insoluble, non-hydrolysable, macromolecular fraction from an acidic sandy forest soil (Cestas, Landes de Gascogne, S.W. France) was examined via chemical degradation and high resolution transmission electron microscopy (HRTEM). Chemical degradation was performed using four reagents (sodium persulfate followed by potassium per...
Article
The insoluble, non-hydrolysable, macromolecular fraction was isolated from an acid sandy forest soil from Cestas (Landes de Gascogne, south west France) through successive hydrolysis with TFA and HCl. This refractory organic matter (ROM) accounts for a large part, ca. one third, of the total organic matter of the soil. Characterisation via a combin...
Article
Aliphatic C most probably derived from ester-bound moieties was found to be present in sandy subsoil horizons. The hydrophobic nature of such compounds may increase their stabilization potential. Therefore, the aim of this study was to investigate the potential of aliphatic compounds in mineral soil horizons along a Dystric Cambisol profile under b...
Article
Two mud volcano fields were explored during the French–Dutch MEDINAUT cruise (1998) with the submersible NAUTILE, one south of Crete along the Mediteranean Ridge at about 2000 m depth (Olimpi mud field) and the other south of Turkey between 1700 and 2000 m depth (Anaximander mud field) where high methane concentrations were measured. Chemosynthetic...
Article
Aliphatic C most probably derived from ester-bound moieties was found to be present in sandy subsoil horizons. The hydrophobic nature of such compounds may increase their stabilization potential. Therefore, the aim of this study was to investigate the potential of aliphatic compounds in mineral soil horizons along a Dystric Cambisol profile under b...
Article
Environmental Context. Nitrogen is an essential element for all living organisms, and its biogeochemical cycle is connected to the cycling of carbon, sulfur, phosphorous, oxygen, and trace metals. Measurement of the isotopic composition of ammonium (NH4+) and nitrate (NO3-) containing samples provides a better understanding of the nitrogen cycle. W...
Article
Most studies of soil organic matter are on humic substances although a substantial contribution of lipids is generally noted for soils. Moreover, soil lipids were shown to have a relatively high resistance to biodegradation. Thus, they could provide information on organic matter sources and diagenetic processes. Soil organic matter is highly hetero...
Article
Current models of soil organic carbon (SOC) include a passive pool representing refractory soil organic matter (RSOM) with turnover times of hundreds to thousands of years. These models suggest that, as total soil C is depleted, it becomes proportionally enriched in RSOM. The objectives of our study were to quantify clay-associated organic matter r...
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A freshwater reservoir (area: 122 km2, volume: 2850 x 10^6 m3, maximum depth: 72 m) located at the outlet of a tropical Andean watershed (Rio Bocono, 1620 km2, 08°57’–09°31’N, 70°02’–70°34’W, NW Venezuela) was studied combining: (1) high resolution monitoring of the major environmental parameters using a CTD probe; (2) dissolved (major and trace) e...
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Sandy soil samples collected from under a woody/grass savanna in the Lamto experimental area (613N, 520W; Cte dIvoire, West Africa), were fractionated according to particle size with the aim of measuring the natural abundance of 15N and determining the contents and composition of hydrolysable carbohydrates of soil organo-mineral particles for a bet...
Article
Soils play an important role in the carbon cycle, and deforestation in the tropics affects both soil carbon storage and CO2 release into the atmosphere. The consequences of deforestation and conversion to pasture for soil carbon content and dynamics were examined in two soil types differing mainly by their texture. Two chronosequences were selected...
Article
Intra-tooth δ18O variations within the carbonate (δ18Oc) and phosphate (δ18Op) components of tooth apatite were measured for Miocene and Pliocene hypsodont mammals from Afghanistan, Greece and Chad in order to evaluate the resistance of enamel to diagenetic alteration. Application of water-apatite interaction models suggest that the different kinet...
Article
A recently developed demineralisation treatment, using 2% hydrofluoric acid, was applied to the <50 mum fraction of a silty loamy soil typical of crop soils from northern France. The material thus isolated was compared with an untreated control through elemental analysis and thermal degradation (Rock-Eval pyrolysis; analysis by combined gas chromat...
Article
The stable carbon isotope compositions of individual n-alkanes extracted from leaves of (1) Ginkgo biloba degrading in a well-drained soil and (2) Eretmophyllum, a fossil Ginkgoale, were investigated in a first approach to refining the estimate of potential diagenetic effects on the isotopic composition of sedimentary alkanes derived from higher pl...
Article
It is commonly predicted that the intensity of primary production and soil carbon (C) content are positively linked. Paradoxically, many long-term field observations show that although plant litter is incorporated to soil in large quantities, soil C content does not necessarily increase. These results suggest that a negative relationship between C...
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Des méthodes de traçage isotopique basées sur l’utilisation de mesures d’activité de traceurs radioactifs ou de teneurs en isotopes stables peuvent nous aider à identifier et quantifier la contribution de sources différentes de carbone organique particulaire dans les écoulements générés par l’érosion hydrique sur les bassins versants ou améliorer l...
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In Peruvian Amazonia, cropping techniques manipulating the biological processes of soil fertility have been tested to increase productivity and sustainability of crops. Special attention was paid to earthworms since their communities are dominant in natural ecosystems and severely depleted in cultivated soils, and also because their populations can...
Article
Modern bone and enamel powders have reacted at 301 K with 13C- and 18O-labelled waters under inorganic and microbial conditions. The aim of the study is to investigate the resistance of stable isotope compositions of bioapatite carbonate (δ13C, δ18Oc) and phosphate (δ18Op) to isotopic alteration during early diagenesis. Rapid and significant carbon...
Article
In Peruvian Amazonia, cropping techniques manipulating the biological processes of soil fertility have been tested to increase productivity and sustainability of crops. Special attention was paid to earthworms since their communities are dominant in natural ecosystems and severely depleted in cultivated soils, and also because their populations can...
Article
It is generally accepted that the low quality of soil carbon limits the amount of energy available for soil microorganisms, and in turn the rate of soil carbon mineralization. The priming effect, i.e. the increase in soil organic matter (SOM) decomposition rate after fresh organic matter input to soil, is often supposed to result from a global incr...
Article
Recent studies have pointed to the occurrence in soil organic matter of an insoluble macromolecular fraction, resistant to drastic alkali and acid hydrolysis. This non-hydrolysable fraction may contribute to the stable carbon pool in the soil and thus be important for the global carbon budget. We have developed a method to isolate such chemically r...
Article
Comparative characterisation of total lipids from fresh leaves and leaves from litter of Ginkgo biloba demonstrated that all lipid constituents were degraded during the early stages of diagenesis. However, as shown by calculation of degradation levels, some of these compounds were preferentially degraded and a stability scale was established for G....
Article
Nitrogen budgets established for large river systems reveal that up to 60% of the nitrate exported from agricultural soils is eliminated, either when crossing riparian wetlands areas before even reaching surface waters, or within the rivers themselves through benthic denitrification. The study of nitrogen isotope ratios of riverine nitrates could o...
Article
A recently described species of mytilid mussel, Bathymodiolus azoricus Von Cosel et al., 1999, was observed to be the dominant organism at the hydrothermal vents off the Azores, at both the Lucky Strike and Menez Gwen sites. Evidence suggests this species of Bathymodiolus represents yet another example of the intriguing dual symbiosis known in thre...
Article
The rich mid-Turolian site of Molayan (Afghanistan) has yielded more than 100 mandibles from the bovid Tragoportax afghanicus. In this study we document different aspects of the paleobiology and paleoecology of this fossil bovid by examining patterns of inter- and intra-tooth carbon and oxygen isotopic analyses in M1 to M3 molars from five specimen...
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Organic carbon (OC) and total nitrogen (TN) concentrations and stable isotope ratios (δ13C, δ15N) of fine (<50 µm) size fractions of deep-sea sediments from the central North Atlantic were employed to identify changes in sources of organic matter over the past 50 ka BP. Ambient glacial sediments are characterised by values that reflect mixtures of...
Article
Palaeoenvironments inferred from stable carbon isotope ratios of fossil plants collected from various environments of the Cenomanian of Bohemia were compared with palaeobotanical and sedimentological data to test the use of isotope ratios as a record of local palaeoenvironments and fossil-plant ecology. A number of isotope and biogeochemical patter...
Conference Paper
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The question of discriminating sources of organic matter in suspended particles of stream flows can be addressed by using total organic carbon (TOC) concentration and stable isotope (13C, 15N) measurements when constant fluxes of organic matter supply can be assumed. However, little is known on the dynamics of organic matter release during soil ero...