Substrate characteristic bacterial fatty acid production based on amino acid assimilation and transformation in marine sediments

ABSTRACT Polar lipid-derived fatty acids (PLFAs) and their stable carbon isotopes are frequently combined to characterize microbial populations involved in the degradation of organic matter, offering a link to biogeochemical processes and carbon sources used. However, PLFA patterns derive from multiple species and may be influenced by substrate types. Here, we investigated such dependencies by monitoring the transformation of position-specifically 13C-labeled amino acids (AAs) in coastal marine sediments dominated by heterotrophic bacteria. Alanine was assimilated into straight-chain FAs, while valine and leucine incorporation led to the characteristic production of even- and odd-numbered iso-series FAs. This suggests that identical microbial communities adjust lipid biosynthesis according to substrate availability. Transformation into precursor molecules for FA biosynthesis was manifested in increased 13C recoveries of the corresponding volatiles acetate, isobutyrate and isovalerate of up to 39.1%, much higher than for PLFAs (<0.9%). A significant fraction of 13C was found in dissolved inorganic carbon (up to 37.9%), while less was recovered in total organic carbon (up to 17.3%). We observed a clear discrimination against the carboxyl C, whereby C2 and C3 positions were preferentially incorporated into PLFAs. Therefore, position-specific labeling is an appropriate tool for reconstructing the metabolic fate of protein-derived AAs in marine environments.

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Influences of Florfenicol Used in Aquaculture on Bacteria in Coastal Marine Sediments

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.518-523.395 ◽

2012 ◽

Vol 518-523 ◽

pp. 395-399

Author(s):

Hu Min Zong ◽

Ju Ying Wang ◽

Ying Ying Hu ◽

Zhi Feng Zhang ◽

De Yi Ma

Keyword(s):

Marine Sediments ◽

Coastal Area ◽

Heterotrophic Bacteria ◽

Current Paper ◽

Resistant Bacteria ◽

Coastal Marine Sediments ◽

Sediment Samples ◽

Coastal Marine ◽

Nitrite Oxidizing Bacteria

Florfenicol is an effective antibacterial that is widely used in aquaculture farms. The current paper aims to investigate the potential influences of florfenicol on the growth and activities of microorganisms in the sediments of the Dalian coastal area using spiked experiments. The florfenicol resistance of heterotrophic bacteria in the sediment samples from different stations is also analyzed. The results show that florfenicol inhibits the growth and nitrification rates of both ammonia- and nitrite-oxidizing bacteria. Moreover, the sediment samples from stations which previously used florfenicol or other antibacterials had higher percentages of florfenicol-resistant bacteria, indicating that the resistance of heterotrophic bacteria in the sediments developed due to the use of antibacterials.

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Dissolved inorganic carbon and alkalinity fluxes from coastal marine sediments: model estimates for different shelf environments and sensitivity to global change

Biogeosciences ◽

10.5194/bg-10-371-2013 ◽

2013 ◽

Vol 10 (1) ◽

pp. 371-398 ◽

Cited By ~ 85

Author(s):

V. Krumins ◽

M. Gehlen ◽

S. Arndt ◽

P. Van Cappellen ◽

P. Regnier

Keyword(s):

Organic Carbon ◽

Marine Sediments ◽

Reactive Transport ◽

Inorganic Carbon ◽

Dissolved Inorganic Carbon ◽

Transport Processes ◽

Coastal Marine Sediments ◽

Coastal Marine ◽

Depositional Flux ◽

Particulate Inorganic Carbon

Abstract. We present a one-dimensional reactive transport model to estimate benthic fluxes of dissolved inorganic carbon (DIC) and alkalinity (AT) from coastal marine sediments. The model incorporates the transport processes of sediment accumulation, molecular diffusion, bioturbation and bioirrigation, while the reactions included are the redox pathways of organic carbon oxidation, re-oxidation of reduced nitrogen, iron and sulfur compounds, pore water acid-base equilibria, and dissolution of particulate inorganic carbon (calcite, aragonite, and Mg-calcite). The coastal zone is divided into four environmental units with different particulate inorganic carbon (PIC) and particulate organic carbon (POC) fluxes: reefs, banks and bays, carbonate shelves and non-carbonate shelves. Model results are analyzed separately for each environment and then scaled up to the whole coastal ocean. The model-derived estimate for the present-day global coastal benthic DIC efflux is 126 Tmol yr−1, based on a global coastal reactive POC depositional flux of 117 Tmol yr−1. The POC decomposition leads to a carbonate dissolution from shallow marine sediments of 7 Tmol yr−1 (on the order of 0.1 Pg C yr−1. Assuming complete re-oxidation of aqueous sulfide released from sediments, the effective net flux of alkalinity to the water column is 29 Teq. yr−1, primarily from PIC dissolution (46%) and ammonification (33%). Because our POC depositional flux falls in the high range of global values given in the literature, the reported DIC and alkalinity fluxes should be viewed as upper-bound estimates. Increasing coastal seawater DIC to what might be expected in year 2100 due to the uptake of anthropogenic CO2 increases PIC dissolution by 2.3 Tmol yr−1and alkalinity efflux by 4.8 Teq. yr−1. Our reactive transport modeling approach not only yields global estimates of benthic DIC, alkalinity and nutrient fluxes under variable scenarios of ocean productivity and chemistry, but also provides insights into the underlying processes.

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Dissolved inorganic carbon and alkalinity fluxes from coastal marine sediments: model estimates for different shelf environments and sensitivity to global change

Biogeosciences Discussions ◽

10.5194/bgd-9-8475-2012 ◽

2012 ◽

Vol 9 (7) ◽

pp. 8475-8539 ◽

Cited By ~ 3

Author(s):

V. Krumins ◽

M. Gehlen ◽

S. Arndt ◽

P. van Cappellen ◽

P. Regnier

Keyword(s):

Organic Carbon ◽

Marine Sediments ◽

Reactive Transport ◽

Inorganic Carbon ◽

Dissolved Inorganic Carbon ◽

Transport Processes ◽

Coastal Marine Sediments ◽

Coastal Marine ◽

Depositional Flux ◽

Particulate Inorganic Carbon

Abstract. We present a one-dimensional reactive transport model to estimate benthic fluxes of dissolved inorganic carbon (DIC) and alkalinity (AT) from coastal marine sediments. The model incorporates the transport processes of sediment accumulation, molecular diffusion, bioturbation and bioirrigation, while the reactions included are the redox pathways of organic carbon oxidation, re-oxidation of reduced nitrogen, iron and sulfur compounds, pore water acid-base equilibria, and dissolution of particulate inorganic carbon (calcite, aragonite, and Mg-calcite). The coastal zone is divided into four environmental units with different particulate inorganic carbon (PIC) and particulate organic carbon (POC) fluxes: reefs, banks and bays, carbonate shelves and non-carbonate shelves. Model results are analyzed separately for each environment and then scaled up to the whole coastal ocean. The model-derived estimate for the present-day global coastal benthic DIC efflux is 126 Tmol yr−1, based on a global coastal reactive POC depositional flux of 117 Tmol yr−1. The POC decomposition leads to a~carbonate dissolution from shallow marine sediments of 7 Tmol yr−1 (on the order of 0.1 Pg C yr−1). Assuming complete re-oxidation of aqueous sulfide released from sediments, the effective net flux of alkalinity to the water column is 29 Teq yr−1, primarily from PIC dissolution (46%) and ammonification (33%). Because our POC depositional flux falls in the high range of global values given in the literature, the reported DIC and alkalinity fluxes should be viewed as upper-bound estimates. Increasing coastal seawater DIC to what might be expected in year 2100 due to the uptake of anthropogenic CO2 increases PIC dissolution by 2.3 Tmol yr−1 and alkalinity efflux by 4.8 Teq yr−1. Our reactive transport modeling approach not only yields global estimates of benthic DIC, alkalinity and nutrient fluxes under variable scenarios of ocean productivity and chemistry, but also provides insights into the underlying processes.

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Effectiveness of Oxygen-Saturated Seawater Injections and Air Sparging Technologies in Remediation of Coastal Marine Sediments from Sludge

Environmental Geochemistry and Health ◽

10.1007/s10653-021-00952-9 ◽

2021 ◽

Author(s):

Borja Ferrández-Gómez ◽

Antonio Sánchez ◽

Juana D. Jordá ◽

Eva S. Fonfría ◽

César Bordehore ◽

...

Keyword(s):

Marine Sediments ◽

Air Sparging ◽

Coastal Marine Sediments ◽

Coastal Marine

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Carbon burial in deep-sea sediment and implications for oceanic inventories of carbon and alkalinity over the last glacial cycle

Climate of the Past ◽

10.5194/cp-14-1819-2018 ◽

2018 ◽

Vol 14 (11) ◽

pp. 1819-1850 ◽

Cited By ~ 11

Author(s):

Olivier Cartapanis ◽

Eric D. Galbraith ◽

Daniele Bianchi ◽

Samuel L. Jaccard

Keyword(s):

Marine Sediments ◽

Active Carbon ◽

Deep Sea ◽

Dissolved Inorganic Carbon ◽

Glacial Cycle ◽

Last Glacial ◽

Carbon Burial ◽

Order Constraint ◽

The Last Glacial ◽

Carbon Inventory

Abstract. Although it has long been assumed that the glacial–interglacial cycles of atmospheric CO2 occurred due to increased storage of CO2 in the ocean, with no change in the size of the “active” carbon inventory, there are signs that the geological CO2 supply rate to the active pool varied significantly. The resulting changes of the carbon inventory cannot be assessed without constraining the rate of carbon removal from the system, which largely occurs in marine sediments. The oceanic supply of alkalinity is also removed by the burial of calcium carbonate in marine sediments, which plays a major role in air–sea partitioning of the active carbon inventory. Here, we present the first global reconstruction of carbon and alkalinity burial in deep-sea sediments over the last glacial cycle. Although subject to large uncertainties, the reconstruction provides a first-order constraint on the effects of changes in deep-sea burial fluxes on global carbon and alkalinity inventories over the last glacial cycle. The results suggest that reduced burial of carbonate in the Atlantic Ocean was not entirely compensated by the increased burial in the Pacific basin during the last glacial period, which would have caused a gradual buildup of alkalinity in the ocean. We also consider the magnitude of possible changes in the larger but poorly constrained rates of burial on continental shelves, and show that these could have been significantly larger than the deep-sea burial changes. The burial-driven inventory variations are sufficiently large to have significantly altered the δ13C of the ocean–atmosphere carbon and changed the average dissolved inorganic carbon (DIC) and alkalinity concentrations of the ocean by more than 100 µM, confirming that carbon burial fluxes were a dynamic, interactive component of the glacial cycles that significantly modified the size of the active carbon pool. Our results also suggest that geological sources and sinks were significantly unbalanced during the late Holocene, leading to a slow net removal flux on the order of 0.1 PgC yr−1 prior to the rapid input of carbon during the industrial period.

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