Concentrations and fluxes of organic carbon substrates in the aquatic environment

1993 ◽  
Vol 63 (3-4) ◽  
pp. 243-274 ◽  
Author(s):  
U. M�nster
Keyword(s):  
Organic Carbon ◽  
Aquatic Environment ◽  
Carbon Substrates

scholarly journals Probing the fate of soil-derived core and intact polar GDGTs in aquatic environments

2014 ◽  
Vol 11 (7) ◽  
pp. 11569-11596
Author(s):  
F. Peterse ◽  
C. M. Moy ◽  
T. I. Eglinton
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
River Water ◽  
Aquatic Environment ◽  
Membrane Lipids ◽  
River Mouth ◽  
Time Frame ◽  
Aquatic Environments ◽  
Relative Distribution ◽  
Sea Transport

Abstract. We have performed incubation experiments in order to examine the fate of branched glycerol dialkyl glycerol tetraether (brGDGT) membrane lipids upon entering an aquatic environment and to asses the suitability of brGDGTs as tracers for fluvial land-sea transport of soil organic carbon. We incubated a soil from the Rakaia River catchment on the South Island of New Zealand using Rakaia River water and ocean water collected near the river mouth as inocula for a period of up to 152 days. The concentrations of brGDGTs derived from intact polar ("living"; IPL) lipids and core ("fossil"; CL) lipids remained stable over the course of the experiment, suggesting an absence of significant brGDGT production or degradation. Moreover, the lack of change in brGDGT distribution during the experiment implies that the initial soil signature remains unaltered during transport through the aquatic environment, at least over the time frame of the experiment. In contrast, the total pool of isoprenoid GDGTs (isoGDGTs), currently attributed to soil Thaumachaeota, increased substantially (27–72%) in all incubation setups by the end of the experiment. As a consequence, a decrease in Branched and Isoprenoid Tetraether (BIT) index values – a proxy for the relative input of fluvially discharged soil material into a marine system – became evident after an incubation period of 30 days, with a maximum final decrease of 0.88 to 0.74 in the experiment with river water. The relative distribution within the isoGDGT pool shows changes with time, suggesting different membrane adaptation rates to the aquatic environment, or a shift in source organism(s). While the stability of soil brGDGTs in aquatic environments reinforces their potential as tracers for land-sea transport of soil organic carbon and their use in paleoclimate reconstructions, the distributional differences between GDGTs in river water and nearby soil indicate that further research is needed to pinpoint the sources of GDGTs that are ultimately discharged to the oceans and are subsequently archived in continental margin sediments.

Synergistic supplementation of organic carbon substrates for upgrading neutral lipids and fatty acids contents in microalga

2021 ◽  
pp. 105482
Author(s):  
Kanda Whangchai ◽  
Thangavel Mathimani ◽  
Manigandan Sekar ◽  
Sabarathinam Shanmugam ◽  
Kathirvel Brindhadevi ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Organic Carbon ◽  
Neutral Lipids ◽  
Carbon Substrates

Prokaryotic diversity in sediments beneath two polar glaciers with contrasting organic carbon substrates

Extremophiles ◽  
2012 ◽  
Vol 16 (2) ◽  
pp. 255-265 ◽  
Author(s):  
Marek Stibal ◽  
Fariha Hasan ◽  
Jemma L. Wadham ◽  
Martin J. Sharp ◽  
Alexandre M. Anesio
Keyword(s):  
Organic Carbon ◽  
Prokaryotic Diversity ◽  
Carbon Substrates
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