{"id":310,"date":"2017-08-14T14:41:01","date_gmt":"2017-08-14T18:41:01","guid":{"rendered":"https:\/\/www2.whoi.edu\/staff\/bvanmooy\/?page_id=310"},"modified":"2021-08-05T11:57:53","modified_gmt":"2021-08-05T15:57:53","slug":"gordon-and-betty-moore-foundation-project-data","status":"publish","type":"page","link":"https:\/\/www2.whoi.edu\/staff\/bvanmooy\/gordon-and-betty-moore-foundation-project-data\/","title":{"rendered":"GBMF Data"},"content":{"rendered":"\n\n\t

Gordon and Betty Moore Foundation Project Data<\/h1>\n\t

Microscale mechanistic linkages between the chemical and physical processes that contribute to marine organic matter degradation. 2015 – present.<\/b><\/h2>\n\t\t\tAbstract<\/a>\n\t\t\t\t\t\t\tCollapse<\/i><\/a>\n\t\t\n

Particulate organic matter (POM) is ubiquitous in marine systems, and its role in the global carbon cycle is defined by microscale interactions between POM and microbes (Jackson, 1989; Azam, 1998; Jackson and Burd, 2002; Malfatti and Azam, 2009; Stocker, 2012). Microbial degradation drives the turnover of the entire reservoir of suspended POM in the surface ocean, which is composed primarily of living or recently dead plankton, on the timescale of every few weeks (IPCC, 2013). The suspended POM that escapes microbial degradation, forms aggregates (e.g.<\/em>, marine snow or fecal pellets), and sinks, is the primary vector of carbon from the surface ocean to the deep ocean (‘biological pump’).\u00a0 However, microbial degradation attenuates this flux as particles sink through the deep sea (Knauer et al., 1979; Martin, 1987; Van Mooy et al., 2002; Buesseler et al., 2007). Since the reservoir of carbon in the surface ocean is in near equilibrium with the CO2<\/sub> in the atmosphere, the activity of microbes on sinking POM is a primary control on Earth’s climate (Kwon et al., 2009).<\/p>\n

Owing to the importance of POM in the marine carbon cycle, POM degradation has been the focus of intense study since the dawn of modern oceanography, and yet this research has yielded very little mechanistic understanding of the microscale chemical and physical interactions underpinning POM degradation. Instead, most work has focused on characterizing POM composition and POM-microbe interactions at the bulk level. For example, bulk transformations in the chemical composition of sinking POM are characterized by a disappearance of readily hydrolysable organic matter, which contributes to the attenuation of the vertical POM flux (Wakeham et al., 1997; Armstrong et al., 2002; Van Mooy et al., 2002; Goutx et al., 2007). Similarly, it is understood that microbes physically interact with sinking POM by encountering particles by Brownian motion or motility, which contributes to dissolution and disaggregation of sinking POM and attenuates flux (Jackson, 1989; Burd et al., 2010). These are among the many bulk chemical and physical effects on POM flux attenuation that have found their way into simple particle export models, and yet the skill of these models is largely insufficient to obtain the predictive value required for inclusion in global climate and carbon biogeochemistry models.<\/p>\n

We posit that developing an understanding of the mechanistic linkages between the microscale chemical and physical processes that contribute to POM degradation is critical to improve models of the marine carbon cycle.<\/p>\n

We propose a pilot-scale study that couples Van Mooy’s recent work on understanding chemically mediated microscale connections between POM and microbes (Hmelo et al., 2011; Van Mooy et al., 2012; Edwards et al., 2015) with Stocker’s recent work on physical interactions between microbes and individual particles at the microscale (Seymour et al., 2010; Stocker, 2012).<\/p>\n

Our goal for this proposed research is to establish relationships between the molecular signatures and microbial mechanisms of POM degradation at the scale of an individual particle. The long-term ambition is to be able to use observations of the molecular composition of sinking POM in the ocean to inform mechanistic models of particle flux attenuation. Our recent work has shown that the chemical composition of sinking POM directly influences flux attenuation through its effects on microbial interactions (Edwards et al., 2015), but we still lack the mechanistic context to establish predictive links to microscale physics behind these interactions.<\/p>\n\t\t\tVan Mooy Lab<\/a>\n\t\t\t\t\t\t\tExpand<\/i><\/a>\n\t\t\n

Running Title: Single Particle Lipidomics<\/p>\n

Jonathan E. Hunter1*, Helen F. Fredricks1, Lars Behrendt2\u2020, Uria Alcolombri2, Shavonna M. Bent1, Roman Stocker2 and Benjamin A. S. Van Mooy1\u2021.<\/p>\n

    \n
  1. Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543-1050, United States of America.<\/li>\n
  2. Institute of Environmental Engineering, ETH Z\u00fcrich, 8093, Switzerland.<\/li>\n<\/ol>\n

    * Current affiliation: Sport and Specialised Analytical Services, LGC, Fordham, 13 Cambridgeshire, CB7 5WW, United Kingdom<\/p>\n

    \u2020 Current affiliation: Department of Organismal Biology, Science for Life Laboratory, Uppsala University, Norbyv\u00e4gen 18A, 75236 Uppsala, Sweden<\/p>\n\n\n

    Sinking particulate organic matter (POM) is a primary component of the ocean’s biological carbon pump that is responsible for carbon export from the surface- to the deep-sea. Lipids derived from plankton compose a significant fraction of sinking POM. Our understanding of planktonic lipid biosynthesis and the subsequent degradation of lipids in sinking POM is based on the analysis of bulk samples that combine many millions of plankton cells or dozens of sinking particles, which averages out natural heterogeneity. We developed and applied a nanoflow- ultrahigh-performance liquid-chromatography electrospray-ionization high-resolution accurate-mass mass spectrometry lipidomic method to show that two types of sinking particles – marine snow and fecal pellets – collected in the western North Atlantic Ocean have distinct lipidomes, providing new insights on their sources and degradation that would not be apparent from bulk samples. We pressed the limit of this approach by examining individual diatom cells from a single culture, finding marked lipid heterogeneity, possibly indicative of fundamental mechanisms underlying cell division. These single-cell data affirm that even cultures of phytoplankton cells should be viewed as mixtures of physiologically distinct populations. Overall, this work reveals previously-hidden lipidomic heterogeneity in natural POM and phytoplankton cells, which may provide critical new insights on microscale chemical and microbial processes that control the export of sinking POM.<\/p>\n

     <\/p>\n\n

    Lipidomics, ocean, carbon export flux, particulate organic matter, marine snow, aggregate, fecal pellet, phytoplankton, single-cell, nano-flow<\/p>\n\n