Abstract:

Sediment was collected November 16, 2010 from the Northern Gulf of Mexico. This dataset includes geochemistry, process rate measurements, and isotopic ratios for both cold seep sediment and incubations that were amended with sulfate-replete seawater and one of four n-alkanes (C1–C4). Initial and final (80 days after incubation) gas concentrations are included.

Suggested Citation:

Girguis, Peter. 2016. Sediment geochemistry and alkane oxidation rates from sediments collected November 2010 and experimental incubations. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7668B7N

Publications:

Bose, A., Rogers, D. R., Adams, M. M., Joye, S. B., & Girguis, P. R. (2013). Geomicrobiological linkages between short-chain alkane consumption and sulfate reduction rates in seep sediments. Frontiers in Microbiology, 4. doi:10.3389/fmicb.2013.00386

Purpose:

The purpose of these data is to investigate the anaerobic oxidation of short-chain n-alkanes coupled with sulfate-reduction in Gulf of Mexico sediments.

Data Parameters and Units:

Depth Range (cm); DIC (mM); d13C - DIC (‰); Hydrogen (nM); DOC (uM); Sulfate (mM); Sulfide (mM); Nitrate and Nitrite (uM); Methane (uM); pH; Sulfate Reduction Rate (nmol cm-3 day-1); Anaerobic Methane Oxidation (nmol cm-3 day-1); treatment; target (bacteria or archaea); SRA accession number; Ethane (uM); Propane (uM); n-butane (uM); Pentane (uM); Rate of alkane consumption (nmol mL-1 day-1); Rate of alkane consumption with molybdate addition (nmol mL-1 day-1) (% inhibition); Observed ratio using total SRR alkane:SO42-; Corrected sulfate reduction rates above the nitrogen control (nmol mL-1 day-1); Observed ratio using corrected SRR alkane:SO42-; Predicted ratio of alkane: SO42-; Sulfate concentration (mM); Sulfide concentration (mM); DIC d13C at Tf; d13C of added gas at T0; d13C of added gas at Tf; Observed C-addition from alkane to DIC pool (mmols C); Predicted DIC production from alkane oxidation (mmols C)*; % alkane C recovered in DIC; Methane produced (mM) SRR = sulfate reduction rate; n.s. = no sample; l.s. = lost sample; i.v. = insufficient volume; b.d.l. = below detection limit; n.a. = not applicable; t0 = initial reading; tf = reading after 80 days of incubation In all cases averages are show +/- standard deviation of three replicates

Methods:

28 mM sodium sulfate and 2 mM sodium sulfide were added to sediment samples. Bottle headspace was then filled with approximately 69 kPa of a single alkane (either methane, ethane, propane, or butane); control samples were filled with pure nitrogen. For the sodium molybdate treatment, sodium molybdate was added to sediment samples (final concentration 28 mM) and the headspace was filled with approximately 69 kPa gas (methane, ethane, propane, butane, or nitrogen). 50 uL subsamples were analyzed using a Hewlett Packard 5890 Series II gas chromatograph with flame ionization detector and RestekRt-XL. A QuantiChrom Sulfate Assay Kit was used for sulfate concentrations. The Stable Isotope Facility at University of California analyzed isotopes using a ThermoScientific PreCon concentration system with a ThermoScientific Delta V Plus isotope ratio mass spectrometer.

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