Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
  • BCO-DMO Processing Description
• Related Publications
• Parameters
• Instruments
• Deployments
• Project Information
• Funding

Sampling protocol:
Samples were collected using a Teflon tow-fish sampling system deployed at approximately 3-meters (m) depth utilizing established trace metal-clean techniques. After sample collection, seawater was filtered on board through acid-washed 0.2-micrometer (μm) filter cartridges and frozen until analysis.

Preconcentration protocol:
Samples for dissolved vitamin analysis were preconcentrated as previously described (Okbamichael and Sañudo-Wilhelmy, 2004; Okbamichael and Sañudo-Wilhelmy, 2005; Sañudo-Wilhelmy et al., 2012; Suffridge et al., 2017). Briefly, preconcentration columns were prepared by pouring 1:1 MeOH: C18 resin (HF Bondesil (Agilent Technologies)) slurry into Poly-Prep Columns (Biorad). The resin was allowed to settle, and the excess MeOH was drained, leaving 7 milliliters (ml) of resin. Thawed samples were adjusted to pH 6.5 using dilute HCl and passed over the preconcentration column at 1 ml per minute. The residual salt was rinsed off the resin using 30 ml of LC/MS grade water. The target analytes were then eluted from the resin using 12 ml of LC/MS grade methanol into methanol-rinsed 15 ml conical centrifuge tubes. Eluted samples were then further concentrated via evaporation in a nitrogen dryer using 5-20 PSI compressed N2 gas, in a dark, at room temperature. Samples were allowed to evaporate until 250 microliters (μl) remained, and then stored at -20 degrees Celsius (°C) until LC/MS analysis, which occurred within 24 hours. Prior to LC/MS analysis, samples were adjusted to pH 6.5 using 10 μl of dilute NaOH.

LC/MS Analysis:
Quantification of vitamin B7 (biotin); four different chemical forms of vitamin B12 ((adenosyl (AB12)-cyano (CB12)-hydroxy (HB12), and methyl (MB12) B12; vitamin B1 (thiamin); two of its precursors (HMP,( 4-Amino-5-hydroxymethyl-2-methylpyrimidine) and cHET (5-(2-Hydroxyethyl)-4-methyl-1,3-thiazole-2-carboxylic acid) as well as HET (4-Methyl-5-thiazoleethanol), precursor of cHET and AmMP (4-amino-5-aminomethyl-2-methylpyrimidine), a salvage compound for the HMP synthesis, was carried out with a Thermo TSQ Altis Plus triple quadrupole mass spectrometer, coupled to a Vanquish Flex UHPLC system. The LC system used a stable-bond C18 reversed-phase column (Discovery HS C18 10cm x 2.1mm, 5μm column, Supelco Analytical) with a 50 μl sample loop. The computer software Trace Finder General 5.2 Quan and TSQ Altis Plus 3.4 Tune (Thermo Scientific) were used for data acquisition and analysis. A 12-minute gradient flow was used with mobile phases of methanol (MeOH) and LC/MS grade water, both buffered to pH 4 with 0.5% acetic acid. The flow rate was set at 230 microliters per minute (μl/min) throughout the run, with a gradient starting at 93% LC/MS water: 7% MeOH for two minutes, changing to 100% MeOH by seven minutes, and continuing at 100% MeOH until nine minutes and returning to initial conditions until the gradient completes at twelve minutes. All peaks were identified using standards dissolved in LC/MS grade water. The mass spectrometer was run in Selected Reaction Monitoring (SRM) mode with positive polarity with a well time of 100 milliseconds (ms) per transition. The resolution of the mass filters used for quadrupoles 1 and 2 were 0.7 and 0.1 m/z, respectively. The ESI spray voltage was 4000V, sheath gas (N2) pressure was 30 PSI, the auxiliary gas (Ar) pressure was 3 PSI, the capillary temperature was 269°C, and the collision pressure was 2.1 torr. B vitamin and vitamer values reported as 0.00 should be interpreted as "non-detectable".

The computer software Trace Finder General 5.2 Quan and TSQ Altis Plus 3.4 Tune (Thermo Scientific) were used for data acquisition and analysis.

- Imported original file "Dataset_MH_B-vitamin concentrations_Final data set_20241206.xlsx" into the BCO-DMO system.
- Renamed fields to comply with BCO-DMO naming conventions.
- Converted date field to YYYY-MM-DD format.
- Saved the final file as "954686_v1_dissolved_b_vitamins_and_vitamers.csv".

NSF Award Abstract:
B-vitamins (thiamin, B1; biotin B7; cobalamin, B12) are organic molecules necessary for all the biological transformations of the chemical elements that support life on Earth. Without the activity of those molecules, the chemistry of life on Earth—as we know it—would end. In marine systems, the availability of B-vitamins also affects food web dynamics by controlling both bacterial and phytoplankton growth and species diversity. Because many organisms that can make several B-vitamins lack the ability to synthesize others, their vitamin needs and environmental accessibility could define which, when, and where specific phytoplankton species flourish. As a result, planktonic communities in nature need to constantly share B-vitamins in a complex mosaic of interdependencies. Despite the early discovery of their relevance in the 1940s, most current marine vitamin research is still based on laboratory experiments or studies focusing on the biological responses of B-vitamin additions on algae and bacteria. Yet, vitamin distributions in the world ocean are mostly unknown, as they have only been measured in a few marine basins. Thus, the actual effect of their natural distributions in phytoplankton communities is still a mystery today. The main goal of this project is to elucidate the effects of B-vitamins availability on the spatial distributions of different phytoplankton species in surface waters of the world ocean. These data are needed to start untangling the rules by which members of the microbial plankton are interconnected through vitamin exchange and to determine how these essential interrelations may control surface ocean ecosystem functioning, such as phytoplankton and bacterial growth. Ultimately understanding these controls and their dynamics is critical to predicting future changes in the marine environment. In the future greenhouse world, the ocean is expected to be of paramount importance, providing the required protein to nurture future human populations and to reduce the levels of human-produced atmospheric CO2 through its uptake by photosynthetic organisms with different vitamin requirements.

This study is to establish the first global map of B-vitamin distributions in surface waters of the world ocean collected during the Malaspina circumnavigation expedition. This global map of vitamins is being used to determine their importance on phytoplankton species biogeography, a still unresolved ecological riddle. Another objective of the study is to establish how ambient vitamin concentrations, combined with bioactive trace elements and macronutrients, promote changes in the relative abundance of different eukaryotic and prokaryotic plankton species on the surface ocean. Overall, this is the first global study on the role of B-vitamins on ecosystem functioning and species composition in subtropical and tropical open ocean environments including the ocean gyres. The investigators are carrying out targeted metagenomic analyses to identify B-vitamins synthesizers and consumers within the planktonic community at several globally distributed stations across the Atlantic, Pacific, and Indian oceans. The extensive datasets already generated by the hundreds of participants of the Malaspina expedition is fully available to interpret the vitamin results. This study allows us to expand our understanding of B-vitamin distributions on a global scale and further investigate how surface ocean’s plankton community dynamics are intertwined with ambient B-vitamin pools.

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.