Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Parameters
• Instruments
• Deployments
• Project Information
• Funding

Porewater sulfate and sulfide concentrations in Alvin pushcore samples collected from Guaymas Basin hydrothermal vents during R/V Atlantis cruise AT42-05 in November 2018. This dataset was obtained at the University of North Carolina Chapel Hill.

Porewater sulfate and sulfide samples from this cruise were also analyzed at the Max Planck Institute for Marine Microbiology. See related dataset: https://www.bco-dmo.org/dataset/816549 (MPI)

This porewater dataset was obtained by Chris Chambers at the University of North Carolina Chapel Hill. The sampling site names in the data are based on Teske et al. 2016.

For analysis at UNC (Chris Chambers), porewater was obtained from freshly collected sediment push cores on R/V Atlantis. The sediment cores were sampled in 3 cm intervals; ca. 40 ml sediment samples were centrifuged in 50 ml conical Falcon tubes for 5 to 10 minutes at approx. 1000 g, until the sediment had settled and produced ca. 8 to 10 ml of porewater. The sediment interval depths are given in the dataset (Sediment_depth). For porewater sulfide analysis, 1 ml porewater subsamples were drawn into syringes, filtered immediately through 0.45 μm filters, and placed in Eppendorf sample vials each containing 0.1 ml of 0.1 M zinc acetate solution to preserve the sulfide as zinc sulfide until analyzed. Sulfide was quantified spectrophotometrically at UNC-Chapel Hill using the methylene blue method (Cline 1969). For sulfate analysis, 1 ml porewater samples were acidified with 50 microliters of 1 N HCl, and bubbled with N2 for 1 minute to remove hydrogen sulfide. After returning the samples to the home laboratory, sulfate concentrations were determined using the ion chromatograph of the UNC Environmental Program.

Problem report: Transport problems have caused sample losses among the porewater samples, which are evident in occasional gaps in porewater profiles.

BCO-DMO Processing:
 - added columns for Site, Sample_type, Lat, Lon, Date, Dive, Core, and Water_depth fields from header rows;
 - renamed fields;
 - removed commas in Site and Sample_type columns.

NSF Award Abstract:
Fungi that can derive energy from chemicals, yet consume other organisms or organic material to obtain carbon have been reported from diverse marine subsurface samples, including from hundreds of meters below the seafloor. Evidence exists that Fungi are active in subsurface marine sediments globally, yet there is a dearth of knowledge on their role in the marine subsurface, and specifically on their role(s) in hydrocarbon degradation within deep-sea sediments. This team is isolating a broad collection of environmentally relevant filamentous Fungi and yeasts from hydrothermally-influenced and hydrocarbon-rich seep sediments of Guaymas Basin using high-throughput culture-based approaches. They aim to reveal the diversity of Fungi and Bacteria in these hydrothermal sediments, how temperature and hydrocarbon composition shape their distribution, and how Fungi cooperate to enhance the degradation of hydrocarbons by Bacteria. By hosting six undergraduates through the WHOI Summer Student Fellows program and the Woods Hole Partnership Education Program, the project contributes to increasing diversity in marine science by offering opportunities for promising undergraduates from disadvantaged populations. High school students are involved in summer projects and in intensive summer workshops. One postdoc, a graduate student, and two Research Associates are supported, and international collaborations are strengthened. The postdoc and graduate student are gaining valuable cruise-based experience. An e-lecture on Fungi and their role(s) in biodegradation of hydrocarbons will be made publicly available by the end of the project. Fungal isolates with accompanying information will be secured in a reference culture collection for long-term storage and are available to any interested researcher throughout the project.

The PIs are isolating a broad collection of environmentally relevant filamentous Fungi and yeasts from hydrothermally-influenced and hydrocarbon-rich seep sediments of Guaymas Basin using high-throughput culture-based approaches, with the aim to reveal their ability to degrade individual hydrocarbons under in situ pressures and temperatures. Culture independent methods marker gene analyses are used to characterize in situ fungal and bacterial diversity and to examine how temperature and hydrocarbon composition shape fungal community composition and distribution. Traditional and comprehensive two-dimensional gas chromatographic analyses are used to examine the complexities and subtle changes in inventories of hydrocarbons within sediment cores, and provide evidence for in situ microbial alteration of individual hydrocarbons. Incubation experiments are used to test the ability of fungal isolates to utilize different hydrocarbons as a sole or auxiliary carbon source under in situ pressures and temperatures and their ability to stimulate biodegradation of hydrocarbons by hydrocarbon-degrading bacteria. Expressed genes within these incubation studies tell us how Fungi and Bacteria couple metabolisms to increase overall specificity and extent of biodegradation of hydrocarbons.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.