Dataset: Results from shipboard high-pressure incubations of diffuse flow vent fluids collected from the Crab Spa and Alvinella sites at East Pacific Rise during the AT26-10 expedition, Jan. 2014 (Microbial Communities at Deep-Sea Vents project)

This dataset includes results from shipboard high-pressure incubations of diffuse flow vent fluids collected from the Crab Spa (9.8398º N, 104.2913º W) and Alvinella (9.8398º N, 104.2915º W) sites at East Pacific Rise during the AT26-10 oceanographic expedition in January 2014. Reported parameters include dates and time elapsed, flow rate, temperature, pressure, and pH, and concentrations of NO3, NH4, H2, H2S, CH4.

Vent fluids used in shipboard incubations were corrected from diffuse flow vent sites at the East Pacific Rise (2503 m): Crab Spa (9.8398º N, 104.2913º W) and Alvinella (9.8398º N, 104.2915º W) (see description in McNichol et al. [2016]). Fluids were collected using isobaric gas-tight samplers [Seewald et al., 2002] prior to their transfer to the shipboard continuous culture system [Foustoukos and Perez-Rodriguez, 2015]. Here, high-pressure incubations (250 bars) were conducted at mesophilic (30 ºC) and thermophilic (50 ºC) conditions to constrain the function and metabolic rates of denitrifying and DNRA microbial communities residing at Crab Spa and Alvinella, respectively. To enhance the activity of nitrate-respiring anaerobic bacteria, an NO3- (5 mm) and H2(aq) (1.30 mM)-enriched medium was introduced in the high-pressure incubations under strictly anaerobic conditions. Dissolved HCO3- (7.3 mm, 13C labeled) was used as added carbon source. Vent fluids were introduced at a flow rate of 0.042 mL/min, while growth medium was added at a rate of 0.0042 mL/min. The two sets of experiments were performed for 356 (Crab Spa) and 50 hours (Alvinella). Direct cell counts were conducted by staining cells with 0.1% acridine orange and counting them with a fluorescence microscope. 15N/14N isotopic analysis of the NO3-, NH4+ and biomass were conducted with a Thermo Scientific Delta VPlus mass spectrometer and CE Instruments NA 2500 series elemental analyzer (EA).

References:

Foustoukos, D., and I. Perez-Rodriguez (2015), A continuous culture system for assessing microbial activities in the piezosphere, Applied and Environmental Microbiology, 81(19), 6850-6856.

McNichol, J., S. P. Sylva, F. Thomas, C. D. Taylor, S. M. Sievert, and J. S. Seewald (2016), Assessing microbial processes in deep-sea hydrothermal systems by incubation at in situ temperature and pressure, Deep Sea Research Part I: Oceanographic Research Papers, 115, 221-232.

Seewald, J. S., K. W. Doherty, T. R. Hammar, and S. P. Liberatore (2002), A new gas-tight isobaric sampler for hydrothermal fluids, Deep-Sea Research, Part I: Oceanographic Research Papers, 49(1), 189-196.