Microbial utilization of terrigenous ancient carbon released to marine environments traced by compound specific radiocarbon dating

2021 ◽  
Author(s):  
Manuel Ruben ◽  
Florence Schubotz ◽  
Hannah Marchant ◽  
Jens Hefter ◽  
Hendik Grotheer ◽  
...  
Keyword(s):  
Organic Matter ◽  
Radiocarbon Dating ◽  
Climate Models ◽  
Future Research ◽  
Microbial Utilization ◽  
Lipid Biomarker ◽  
Biomarker Analysis ◽  
Permafrost Soils ◽  
Micro Organisms ◽  
Global Carbon

<p>Until two decades ago, ancient carbon was regarded as non-bioavailable substrate for organisms because it was synthesised, deposited, and once before (partially) degraded thousands to millions of years ago. Such aged organic matter is stored in terrestrial permafrost deposits or sedimentary bedrock, where it is locked up and remains disconnected from the active global carbon cycle. However, with changing climatic conditions, these organic matter reservoirs are being remobilised at faster rates by receding glaciers or permafrost thaw. During transport and after redeposition in newly formed sediments, the ancient carbon can be accessed by micro-organisms, but whether or not the micro-organisms can utilize the ancient carbon is highly debated.</p><p>Using a combined approach of lipid biomarker analysis, lipidology, and radiocarbon dating of bulk organic matter as well as single compounds targeting intact polar lipid fatty acids (IPL-FAs), our research demonstrates that microbial communities utilise supposedly non-bioavailable ancient carbon for biosynthesis in Arctic marine fjord sediments. The availability of ancient carbon to the sub-surface microbes represents a carbon source that has not been accounted for in today’s climate models. These implications are of major importance concerning the increased thawing of high latitude permafrost soils, permafrost mobilization and coastal erosion due to anthropogenic climate change, catalysing associated positive feedback loops. In future research, we will use this approach to study the utilization of ancient carbon derived from North American and Siberian permafrost soils in Arctic shelf sediments to assess its importance in the global carbon budgets.</p>

scholarly journals Analyses of depositional environments of the Marcellus formation in New York using biomarker and trace metal proxies

2021 ◽  
Author(s):  
Reilly M. Blocho ◽  
Richard W. Smith ◽  
Mark R. Noll
Keyword(s):  
Fatty Acids ◽  
New York ◽  
Organic Matter ◽  
New York State ◽  
Depositional Environments ◽  
Average Chain Length ◽  
Lipid Biomarker ◽  
Two Samples ◽  
Biomarker Analysis ◽  
Marcellus Formation

AbstractThe purpose of this study was to observe how the composition of organic matter (OM) and the extent of anoxia during deposition within the Marcellus Formation in New York varied by distance from the sediment source in eastern New York. Lipid biomarkers (n-alkanes and fatty acids) in the extractable organic component (bitumen) of the shale samples were analyzed, and proxies such as the average chain length (ACL), aquatic to terrestrial ratio (ATR) and carbon preference index (CPI) of n-alkanes were calculated. Fatty acids were relatively non-abundant due to the age of the shale bed, but n-alkane distributions revealed that the primary component of the OM was terrigenous plants. The presence of shorter n-alkane chain lengths in the samples indicated that there was also a minor component of phytoplankton and algal (marine) sourced OM. Whole rock analyses were also conducted, and cerium anomalies were calculated as a proxy for anoxia. All samples had a negative anomaly value, indicating anoxic conditions during deposition. Two samples, however, contained values close to zero and thus were determined to have suboxic conditions. Anoxia and total organic matter (TOM) did not show any spatial trends across the basin, which may be caused by varying depths within the basin during deposition. A correlation between nickel concentrations and TOM was observed and indicates that algae was the primary source of the marine OM, which supports the lipid biomarker analysis. It was determined that the kerogen type of the Marcellus Formation in New York State is type III, consistent with a methane-forming shale bed.

Aquatic Resources in Foodcrusts: Identification and Implication

Radiocarbon ◽  
2015 ◽  
Vol 57 (4) ◽  
pp. 707-719 ◽  
Author(s):  
Carl Heron ◽  
Oliver E Craig
Keyword(s):  
Radiocarbon Dating ◽  
Isotopic Analysis ◽  
Aquatic Resources ◽  
Carbon And Nitrogen ◽  
Lipid Biomarker ◽  
Biomarker Analysis ◽  
Compound Specific Carbon Isotope ◽  
Analytical Approaches ◽  
Isotope Measurements ◽  
Selection Of

Foodcrusts, the charred surface deposits on pottery vessel surfaces, provide a rich source of data regarding container function. This article reviews recent applications focusing on the detection of aquatic resources (marine and freshwater) in pottery vessels using a range of analytical approaches including bulk isotope measurements of carbon and nitrogen, lipid biomarker analysis, and compound-specific carbon isotope determinations. Such data can help to evaluate the presence of reservoir effects when undertaking radiocarbon dating of foodcrust samples. In particular, molecular and isotopic analysis can aid in the selection of suitable candidates for14C where it can be demonstrated that aquatic resources are unlikely to contribute to the residue. Prospects for compound-specific14C analysis of lipids in foodcrusts and ceramic-absorbed residues are also discussed.

Quantification of biomarkers as an estimation of soil organic matter turnover and sources under a crop rotation

2021 ◽  
Author(s):  
Layla M. San-Emeterio ◽  
Ian D. Bull ◽  
Jens Holtvoeth ◽  
Rafael López ◽  
Francisco J. González-Vila ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Crop Rotation ◽  
Total Lipid ◽  
C3 Plant ◽  
Organic Matter Turnover ◽  
Lipid Biomarker ◽  
Biomarker Analysis ◽  
The Impact

<p>Lipid biomarker analysis is an efficient tool for tracing organic matter sources in diverse environments. The quantification of biomarkers facilitates the location of soil organic carbon (SOC) from different sources in a soil profile. According to their structure, biomarkers from total lipid extracts (TLE) would exhibit different degrees of susceptibility to degradation, affecting thus their preservation in soils. Hence, it is crucial to better identify these biomarkers according to diverse stability scales. The aim of this study is to assess SOC contributions from aboveground and to develop a wider approach based on the allocation of C to quantitatively assess the sources of organic matter in low SOM content, highly weathered Mediterranean soils, following a C3-C4 rotation experiment.</p><p>Soil samples were taken from three depth intervals (0-5, 5-20, 20-40 cm) from a Mediterranean agricultural soil at “La Hampa” experimental station used for a crop rotation experiment with wheat (C3 plant) and maize (C4 plant). Lipids were extracted and quantified as described in [1].</p><p>The total lipid extracts were dominated by a homologous series of n-alkanols (saturated alcohols), short-, mid- and long-chain fatty acid methyl ester (FAME), branched FAME, unsaturated (mono- and polyunsaturated) FAME and sterols. Short-chain FAME, monounsaturated FAME were the most abundant fractions of free lipids. Mono-unsaturated alkanoic acids (Cn:1 FA) were detected in considerable amounts in all samples, namely various isomers of C16:1, C18:1, C20:1 and C22:1; these are believed to be mainly synthesised by soil bacteria. A significant increase of these compounds in rotation plots leads to an effective microbial consumption of labile organic matter in the surface soil [2]. Regarding FAME, the observed chain lengths ranged from C13 to C32, showing a unimodal distribution maximising at C16 and C18. These compounds are attributed also to microbial products, supporting our findings from the high proportion of the monounsaturated compounds found. In general, and in relation with all compounds, the abundances increased up to 20% compared with the control plots representing the initial content.</p><p>These results indicate that, only after three years of crop rotation, a considerable contribution of soil organic carbon is inherited from bacterial activity. The combination of extractable lipids has been shown to validate the use of TLE as a proxy for source and other information on vegetation change and soil processes. This work will bring a discussion on the use of these compounds for tracing the impact of crop rotation on carbon storage.</p><p>Acknowledgement: Ministerio de Ciencia Innovación y Universidades (MICIU) for INTERCARBON project (CGL2016-78937-R). L. San Emeterio also thanks MICIU for funding FPI research grants (BES-2017-07968). Mrs Desiré Monis is acknowledged for technical assistance.</p><p>[1] M. San-Emeterio, L., Bull, I. D., Holtvoeth, J., and González-Pérez, J. A.: Compound-specific isotopic analysis of fatty acids in three soil profiles to estimate organic matter turnover in agricultural soils., <em>EGU General Assembly 2020</em>, Online, 4–8 May 2020, EGU2020-18526, https://doi.org/10.5194/egusphere-egu2020-18526, 2020.</p><p>[2] Tu, T. T. N., Egasse, C., Anquetil, C., Zanetti, F., Zeller, B., Huon, S., & Derenne, S. (2017). Leaf lipid degradation in soils and surface sediments: A litterbag experiment. <em>Organic Geochemistry</em>, 104, 35-41.</p>

scholarly journals Origin of lipid biomarkers in mud volcanoes from the Alboran Sea, western Mediterranean

2014 ◽  
Vol 11 (12) ◽  
pp. 3187-3204 ◽  
Author(s):  
C. López-Rodríguez ◽  
A. Stadnitskaia ◽  
G. J. De Lange ◽  
F. Martínez-Ruíz ◽  
M. Comas ◽  
...  
Keyword(s):  
Organic Matter ◽  
Western Mediterranean ◽  
Lipid Biomarkers ◽  
Anaerobic Oxidation Of Methane ◽  
Mud Volcanoes ◽  
Alboran Sea ◽  
Methane Seepage ◽  
Lipid Biomarker ◽  
Biomarker Analysis ◽  
Alborán Sea

Abstract. Mud volcanoes (MVs) are the most prominent indicators of active methane/hydrocarbon venting at the seafloor on both passive and active continental margins. Their occurrence in the western Mediterranean is patent at the West Alboran Basin, where numerous MVs develop overlaying a major sedimentary depocentre containing overpressured shales. Although some of these MVs have been studied, the detailed biogeochemistry of expelled mud so far has not been examined in detail. This work provides the first results on the composition and origin of organic matter, anaerobic oxidation of methane (AOM) processes and general characteristics on MV dynamics using lipid biomarkers as the main tool. Lipid biomarker analysis was performed on MV expelled material (mud breccias) and interbedded hemipelagic sediments from Perejil, Kalinin and Schneider's Heart MVs located in the northwest margin of the Alboran Sea. The n alkane distributions and n alkane-derived indices (CPI and ACL), in combination with the epimerization degree of hopanes (22S/(22S+22R)) indicate that all studied mud breccia have a similar biomarker composition consisting of mainly thermally immature organic matter with an admixture of petroleum-derived compounds. This concordant composition indicates that common source strata must feed all three studied MVs. The past or present AOM activity was established using lipid biomarkers specific for anaerobic methanotrophic archaea (irregular isoprenoids and dialkyl glycerol diethers) and the depleted carbon isotope composition (δ13C) of crocetane/phytane. The presence of these lipid biomarkers, together with the low amounts of detected glycerol dialkyl glycerol tetraethers, is consistent with the dominance of anaerobic methanotrophs of the ANME-2 over ANME-1, at least in mud breccia from Perejil MVs. In contrast, the scarce presence or lack of these AOM-related lipid biomarkers in sediments from Kalinin and Schneider's Heart MVs, suggests that no recent active methane seepage has occurred at these sites. Moreover, the observed methane concentrations support the current activity of Perejil MV, and the very low methane seepage activity in Kalinin and Schneider's Heart MVs.

scholarly journals Permafrost soils and carbon cycling

SOIL ◽  
2015 ◽  
Vol 1 (1) ◽  
pp. 147-171 ◽  
Author(s):  
C. L. Ping ◽  
J. D. Jastrow ◽  
M. T. Jorgenson ◽  
G. J. Michaelson ◽  
Y. L. Shur
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Climatic Conditions ◽  
Permafrost Region ◽  
Abstract Knowledge ◽  
Soil Structures ◽  
Permafrost Soils ◽  
Temperate Soils ◽  
Pedogenic Processes ◽  
Global Carbon

Abstract. Knowledge of soils in the permafrost region has advanced immensely in recent decades, despite the remoteness and inaccessibility of most of the region and the sampling limitations posed by the severe environment. These efforts significantly increased estimates of the amount of organic carbon stored in permafrost-region soils and improved understanding of how pedogenic processes unique to permafrost environments built enormous organic carbon stocks during the Quaternary. This knowledge has also called attention to the importance of permafrost-affected soils to the global carbon cycle and the potential vulnerability of the region's soil organic carbon (SOC) stocks to changing climatic conditions. In this review, we briefly introduce the permafrost characteristics, ice structures, and cryopedogenic processes that shape the development of permafrost-affected soils, and discuss their effects on soil structures and on organic matter distributions within the soil profile. We then examine the quantity of organic carbon stored in permafrost-region soils, as well as the characteristics, intrinsic decomposability, and potential vulnerability of this organic carbon to permafrost thaw under a warming climate. Overall, frozen conditions and cryopedogenic processes, such as cryoturbation, have slowed decomposition and enhanced the sequestration of organic carbon in permafrost-affected soils over millennial timescales. Due to the low temperatures, the organic matter in permafrost soils is often less humified than in more temperate soils, making some portion of this stored organic carbon relatively vulnerable to mineralization upon thawing of permafrost.

scholarly journals Origin of lipid biomarkers in mud volcanoes from the Alboran Sea, western Mediterranean

2013 ◽  
Vol 10 (11) ◽  
pp. 18853-18892
Author(s):  
C. López-Rodríguez ◽  
A. Stadnitskaia ◽  
G. J. De Lange ◽  
F. Martínez-Ruíz ◽  
M. Comas ◽  
...  
Keyword(s):  
Organic Matter ◽  
Western Mediterranean ◽  
Lipid Biomarkers ◽  
Anaerobic Oxidation Of Methane ◽  
Mud Volcanoes ◽  
Alboran Sea ◽  
Methane Seepage ◽  
Lipid Biomarker ◽  
Biomarker Analysis ◽  
Alborán Sea

Abstract. Mud volcanoes (MVs) are the most prominent indicators of active methane/hydrocarbon venting at the seafloor on both passive and active continental margins. Their occurrence in the Western Mediterranean is patent at the West Alboran Basin, where numerous MVs develop overlaying a major sedimentary depocenter containing overpressured shales. Although some of these MVs have been studied, the detailed biogeochemistry of expelled mud so far has not been examined in detail. This work provides the first results on the composition and origin of organic matter, Anaerobic Oxidation of Methane (AOM) processes and general characteristics on MV dynamics using lipid biomarkers as the main tool. Lipid biomarker analysis was performed on MV expelled material (mud breccias) and interbedded hemipelagic sediments from Perejil, Kalinin and Schneider's Heart MVs located in the northwest margin of the Alboran Sea. The n-alkane-distributions and n-alkane-derived indices (CPI and ACL), in combination with the epimerization degree of hopanes (22S/(22S + 22R)) indicate that all studied mud breccia have a similar biomarker composition consisting of mainly thermally immature organic matter with an admixture of petroleum-derived compounds. This concordant composition indicates that common source strata must feed all three studied MVs. The past or present AOM activity was established using lipid biomarkers specific for anaerobic methanotropic archaea (irregular isoprenoids and DGDs) and the depleted carbon isotope composition (δ13C) of crocetane/phytane. The presence of these lipid biomarkers, together with the low amounts of detected GDGTs, is consistent with the dominance of anaerobic methanotrophs of the ANME-2 over ANME-1, at least in mud breccia from Perejil MVs. In contrast, the scarce presence or lack of these AOM-related lipid biomarkers in sediments from Kalinin and Schneider's Heart MVs, suggest no recent active methane seepage has occurred at these sites. Moreover, the observed methane concentrations support the current activity of Perejil MV, and the very low methane seepage activity in Kalinin and Schneider's Heart MVs.

scholarly journals Organic matter characteristics in yedoma and thermokarst deposits on Baldwin Peninsula, west Alaska

2018 ◽  
Vol 15 (20) ◽  
pp. 6033-6048 ◽  
Author(s):  
Loeka L. Jongejans ◽  
Jens Strauss ◽  
Josefine Lenz ◽  
Francien Peterse ◽  
Kai Mangelsdorf ◽  
...  
Keyword(s):  
Organic Matter ◽  
Lake Sediments ◽  
Lake Basin ◽  
Study Region ◽  
Thermokarst Lake ◽  
Discontinuous Permafrost ◽  
Lipid Biomarker ◽  
Biomarker Analysis ◽  
Thawing Permafrost

Abstract. As Arctic warming continues and permafrost thaws, more soil and sedimentary organic matter (OM) will be decomposed in northern high latitudes. Still, uncertainties remain in the quality of the OM and the size of the organic carbon (OC) pools stored in different deposit types of permafrost landscapes. This study presents OM data from deep permafrost and lake deposits on the Baldwin Peninsula which is located in the southern portion of the continuous permafrost zone in west Alaska. Sediment samples from yedoma and drained thermokarst lake basin (DTLB) deposits as well as thermokarst lake sediments were analyzed for cryostratigraphical and biogeochemical parameters and their lipid biomarker composition to identify the belowground OC pool size and OM quality of ice-rich permafrost on the Baldwin Peninsula. We provide the first detailed characterization of yedoma deposits on Baldwin Peninsula. We show that three-quarters of soil OC in the frozen deposits of the study region (total of 68 Mt) is stored in DTLB deposits (52 Mt) and one-quarter in the frozen yedoma deposits (16 Mt). The lake sediments contain a relatively small OC pool (4 Mt), but have the highest volumetric OC content (93 kg m−3) compared to the DTLB (35 kg m−3) and yedoma deposits (8 kg m−3), largely due to differences in the ground ice content. The biomarker analysis indicates that the OM in both yedoma and DTLB deposits is mainly of terrestrial origin. Nevertheless, the relatively high carbon preference index of plant leaf waxes in combination with a lack of a degradation trend with depth in the yedoma deposits indicates that OM stored in yedoma is less degraded than that stored in DTLB deposits. This suggests that OM in yedoma has a higher potential for decomposition upon thaw, despite the relatively small size of this pool. These findings show that the use of lipid biomarker analysis is valuable in the assessment of the potential future greenhouse gas emissions from thawing permafrost, especially because this area, close to the discontinuous permafrost boundary, is projected to thaw substantially within the 21st century.

scholarly journals Biotic and Abiotic Factors Influencing Arsenic Biogeochemistry and Toxicity in Fluvial Ecosystems: A Review

2020 ◽  
Vol 17 (7) ◽  
pp. 2331
Author(s):  
Laura Barral-Fraga ◽  
María Teresa Barral ◽  
Keeley L. MacNeill ◽  
Diego Martiñá-Prieto ◽  
Soizic Morin ◽  
...  
Keyword(s):  
Abiotic Factors ◽  
Arsenic Exposure ◽  
Inorganic Arsenic ◽  
Future Research ◽  
Strong Impact ◽  
Trophic Relations ◽  
Fluvial Systems ◽  
Pampean Streams ◽  
Micro Organisms ◽  
Different Origins

This review is focused on the biogeochemistry of arsenic in freshwaters and, especially, on the key role that benthic microalgae and prokaryotic communities from biofilms play together in through speciation, distribution, and cycling. These microorganisms incorporate the dominant iAs (inorganic arsenic) form and may transform it to other arsenic forms through metabolic or detoxifying processes. These transformations have a big impact on the environmental behavior of arsenic because different chemical forms exhibit differences in mobility and toxicity. Moreover, exposure to toxicants may alter the physiology and structure of biofilms, leading to changes in ecosystem function and trophic relations. In this review we also explain how microorganisms (i.e., biofilms) can influence the effects of arsenic exposure on other key constituents of aquatic ecosystems such as fish. At the end, we present two real cases of fluvial systems with different origins of arsenic exposure (natural vs. anthropogenic) that have improved our comprehension of arsenic biogeochemistry and toxicity in freshwaters, the Pampean streams (Argentina) and the Anllóns River (Galicia, Spain). We finish with a briefly discussion of what we consider as future research needs on this topic. This work especially contributes to the general understanding of biofilms influencing arsenic biogeochemistry and highlights the strong impact of nutrient availability on arsenic toxicity for freshwater (micro) organisms.

scholarly journals Microbial signature lipid biomarker analysis - an approach that is still preferred, even amid various method modifications

2015 ◽  
Vol 118 (6) ◽  
pp. 1251-1263 ◽  
Author(s):  
C. Willers ◽  
P.J. Jansen van Rensburg ◽  
S. Claassens
Keyword(s):  
Lipid Biomarker ◽  
Biomarker Analysis
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