Boiteau Lab



Kew, W., Boiteau, R. M., Eiler, J. M., Paša Tolić, L., & Moran, J. J. (2023). Natural Abundance Isotope Ratio Measurements of Organic Molecules Using 21 T FTICR MS. Analytical Chemistry, 22, 41. 

Subtle variations in stable isotope ratios at natural abundance are challenging to measure but can yield critical insights into biological, physical, and geochemical processes. Well-established methods, particularly multicollector, gas-source, or plasma isotope ratio mass spectrometry, are the gold standard for stable isotope measurement, but inherent limitations in these approaches make them ill-suited to determining site-specific and multiply substituted isotopic abundances. Here, we report the first use of Fourier transform ion cyclotron resonance mass spectrometry for the accurate and precise determination of δ13C and δ15N in caffeine isotopologues. We further report the ability to make these measurements with online liquid chromatography, enabling applications of this approach to complex mixtures.

Koedooder, C., Zhang, F., Wang, S., Basu, S., Haley, S. T., Tolic, N., Nicora, C. D., Glavina, T., Rio, D., Dyhrman, S. T., Gledhill, M., Boiteau, R. M., Rubin-Blum, M., & Shaked, Y. (2023). Taxonomic distribution of metabolic functions in bacteria associated with Trichodesmium consortia. MSystems.

The photosynthetic and diazotrophic cyanobacterium Trichodesmium is a critical marine organism responsible for up to half of ocean nitrogen fixation. Trichodesmium form colonies that harbor a distinct microbiome that expand Trichodesmium’s functional potential and is predicted to influence the cycling of carbon, nitrogen, phosphorus, and iron (C, N, P, and Fe). To link the bacteria associated with Trichodesmium to key functional traits and elucidate how community structure can influence nutrient cycling, we characterized Red Sea Trichodesmium colonies using metagenomics and metaproteomics. The analysis supports Trichodesmium as an active hotspot for C, N, P, Fe, and vitamin exchange. In turn, Trichodesmium may rely on associated bacteria to meet its high Fe demand as several can synthesize photolabile siderophores which can enhance the bioavailability of particulate Fe to the entire consortium. Trichodesmium’s reliance on its microbiome and the observed redundancy of key functional traits likely underpins the dominance and resileincy of Trichodesmium.

Moffett, J. W., & Boiteau, R. M. (2023). Metal Organic Complexation in Seawater: Historical Background and Future Directions. Annual Review of Marine Science, 16(1).

The speciation of most biologically active trace metals in seawater is dominated by complexation by organic ligands. This review traces the history of work in this area, from the early observations that showed surprisingly poor recoveries using metal preconcentration protocols to the present day, where advances in mass spectroscopy and stable isotope geochemistry are providing new insights into the structure, origin, fate, and biogeochemical impact of organic ligands. 

Dewey, C; Kaplan, D. I., Fendorf, S., Boiteau, R. M. (2023) Quantitative Separation of Unknown Organic-Metal Complexes by Liquid Chromatography – Inductively Coupled Plasma – Mass Spectrometry. Analytical Chemistry, 95(20), 7960–7967. 

Accurately quantifying metal-organic species by LC-ICPMS has remained an analytical challenge due to drifting sensitivities during chromatographic separations. This paper developed a new 'gold standard' methods for separating and quantifying metal species from environmental samples that yields near-quantitative recoveries for a wide range of transition metals. 

Miranda, C, Boiteau R. M., McKenna A. M., Knapp A. N. (2023) Quantitative and qualitative comparison of marine dissolved organic nitrogen recovery using solid phase extraction. Limnol. Oceanogr. Methods. 21, 467–477 

Marine dissolved organic carbon and nitrogen (DOC and DON) are major global carbon and nutrient reservoirs, and their characterization relies on extraction methods for preconcentration and salt removal. Existing methods optimize for capturing and describing DOC. This study reports an optimized solid phase extraction strategy to recover marine DON for subsequent molecular characterization.  The approach provides a methodological basis for understanding how DON composition varies across the ocean and determine the processes that govern the supply and removal of this critical organic nutrient. 


Boiteau, R. M.; Repeta, D. J. Slow Kinetics of Iron Binding to Marine Ligands in Seawater Measured by Isotope Exchange Liquid Chromatography − Inductively Coupled Plasma Mass Spectrometry. (2022) Environmental Science and Technology, 56(6), 3770-3779,.

Current understanding of dissolved iron (Fe) speciation in the ocean is largely based on liquid chromatography mass spectrometry methods that characterize ligands at a molecular level, but the kinetic and thermodynamic metal-binding properties of these metal species has remained difficult to determine.  This paper describes a method for determining Fe–ligand dissociation rate constants (kd) of suites of naturally occurring ligands in seawater by monitoring the exchange of ligand-bound 56Fe with 57Fe using liquid chromatography–inductively coupled mass spectrometry. These measurements provide critical information needed to develop metal speciation models that can deconvolve the molecular complexity found in the environment.

Casey, J. R.; Boiteau, R. M.; Engqvist, M. K. M.; Finkel, Z. V; Li, G.; Liefer, J.; Müller, C. L.; Muñoz, N.; Follows, M. J. Basin-Scale Biogeography of Marine Phytoplankton Reflects Cellular-Scale Optimization of Metabolism and Physiology. Science Adv. 2022, 8 (3).

Phytoplankton serve as the foundation of marine ecosystems. A curious aspect of  the most abundant phytoplantkon, prochlorococcus, is their very small genomes and significant diversity across environmental gradients, reflecting genome streamlining that optimizes cellular fitness.  To interpret the structuring role of variations in genetic potential, as well as metabolic and physiological acclimation, we developed a mechanistic constraint-based modeling framework that incorporates the full suite of genes, proteins, metabolic reactions, pigments, and biochemical compositions of 69 sequenced isolates spanning the Prochlorococcus pangenome. Predicted growth rates covaried with observed ecotype abundances, affirming their significance as a measure of fitness. Our study demonstrates the potential to interpret global-scale ecosystem organization in terms of cellular-scale metabolic processes.






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