Postdocs Propel Scientific Discovery

Over the last year, 688 researchers have come to the Environmental Molecular Sciences Laboratory (EMSL) to access instrumentation and expertise in their pursuit of scientific discovery. 

Among the number of scientists who came to EMSL were 127 users who are postdoctoral researchers. We are featuring three users this week in honor of the 13th National Postdoc Appreciation Week and their contributions to science.  

We asked Paula Dalcin Martins, Christian Dewey, and Anna Bennett to share their professional path to becoming a scientist and about their involvement with their EMSL-funded project.  

Paula Dalcin Martins  

Paula Dalcin Martins is a VENI Postdoctoral Research Fellow at the University of Groningen who was recently awarded funding through the Facilities Integrating Collaborations for User Science (FICUS) program to study the impacts of viruses on soil organic carbon and greenhouse gas emissions from agricultural peat soils. She is working with EMSL’s Environmental Transformations and Interactions science area and more specifically, the Terrestrial-Atmosphere Processes and Biomolecular Pathways Integration Research Platforms. Through the FICUS funding, Dalcin Martins will use EMSL’s nuclear magnetic resonance, mass spectrometry, ion chromatography, and X-ray diffraction instrumentation.  

What is your research area? 

I study how microorganisms and viruses drive the biogeochemical cycles in order to better understand, predict, and eventually control ecosystem function. I am particularly interested in biogeochemical reactions that result in greenhouse gas emissions, given the threats of climate feedback loops and the urgency of climate action. I believe that if we can deeply understand the network of interactions between microorganisms and the environment, we can modulate biogeochemical reactions for desired outcomes, such as decreased greenhouse gas emissions, carbon sequestration, and removal of environmental pollutants. 

Why did you want to be a scientist? 

So many reasons! I am delighted when I discover something and know I am the first person in the world to know about it. I am very curious about what exists in the universe and how things work. I love to have a global community of scientists to exchange and collaborate with. I am very passionate about teaching and mentorship and get a lot of energy from helping students achieve their goals and from working on my own growth as a mentor. Finally, science is a wonderful way to serve society in meeting key needs and grand challenges. 

What big challenge do you hope to tackle during your career? 

I am working to leave a legacy on paths to novel solutions to mitigate and adapt to environmental change. The challenge is too big for one single person to tackle, but I dream to make a strong contribution. I think it will take the entire scientific community working on this, including social scientists and policy makers, to meet this grand challenge. In my career, I want to advance our quantitative and mechanistic understanding of the biogeochemical cycles and unravel key microbial and viral players that we may potentially harness for modulation of ecosystem outcomes. 

When did you become an EMSL user and can you explain the potential impact for your research? 

I became an EMSL user when my PhD advisor, Professor Mike Wilkins, got funding to access EMSL resources, including nuclear magnetic resonance and Fourier transform ion cyclotron resonance mass spectrometry. Working together with EMSL has been great not only for access to state-of-the-art resources, but also for exchange of scientific ideas with EMSL staff, who are experts in the field. I recently got a FICUS grant to work together with EMSL and the Joint Genome Institute again. I am beyond excited and thankful. The impact for an early career researcher like me is huge in supporting me to establish my independent research program. 

What university did you join us from? 

During my PhD, from the Ohio State University, and now from the University of Groningen in the Netherlands. 

What do you enjoy doing in your free time? 

I paint, meditate, listen to music and podcasts, walk/hike, visit museums, and sometimes travel on the weekends to explore a new city or nature area with my husband and friends. I also have two mini pigs that we rescued and who now live in our garden, and I enjoy petting them and watching them do their funny pig activities. 

Christian Dewey

Christian Dewey is a postdoctoral researcher at Oregon State University who has been working with Scott Fendorf of Stanford University on an EMSL Large-Scale Research project, "Deciphering controls on metal migration within floodplains: The critical role of redox environments on metal-organic complexes." Their project is aligned with EMSL’s Environmental Transformations and Interactions science area. Through the Biogeochemical Transformations Integrated Research Platform, Dewey has been using multiple mass spectrometers, including Orbitrap, Mossbauer spectroscopy, Fourier-transform ion cyclotron resonance, and X-ray diffraction.  

What is your research area?  

The goal of my research is to understand the molecular mechanisms that govern the speciation, reactivity, and transformation of metals in soils, sediments, and aquatic systems. Metals can be both (micro)nutrients and contaminants, as well as mediators of contaminant cycles. I examine how shifts in biogeochemical and hydrologic conditions alter the molecular mechanisms that ultimately affect the mobility and uptake of metals, and thus their impact on biota and ecosystems.  

Why did you want to be a scientist? 

I was an English major in undergrad, but I found myself drawn to issues related to water resources—and especially water quality—in the first few years after college. I returned to school to pursue this interest, and I quickly discovered that I enjoyed learning about the biogeochemical and hydrologic processes that determine water quality. I eventually began working in an aquatic chemistry lab and found that I also enjoyed the process of scientific research. From there, I began a PhD program in soil and aquatic chemistry and embarked on my training as a research scientist.  

What big challenge do you hope to tackle during your career? 

From alpine wetlands to the ocean floor, dissolved organic matter (DOM) plays a central role in controlling the solubility—and therefore transport and uptake—of trace metals. However, the molecular properties of DOM that determine metal binding, as well as the underlying determinants of these properties, are largely uncharacterized, due to the difficulty of directly measuring metal-organic species in the chemically complex mixture of DOM. Addressing the latter challenge, I am developing new analytical tools and computational methods to characterize and quantify organic-metal species in DOM. I hope to apply these tools to develop a mechanistic understanding of DOM-metal interactions in soil and aquatic systems. Such an understanding would improve metal speciation models, which are used to predict the chemical form of trace metals and are often a key component of field-scale models that predict metal contaminant fate.  

When did you become an EMSL user and can you explain the potential impact for your research? 

I became an EMSL user in the third year of my PhD (2017).  

I am developing new mass spectrometry tools and computational methods with EMSL’s Yuri Corillo, Will Kew, and Rene Boiteau to quantify and characterize dissolved organic-metal species in environmental systems. These novel approaches are needed to develop a molecular understanding of DOM-metal interactions, which often control the solubility and reactivity—and the therefore mobility and uptake—of trace metals in marine and terrestrial environments.  

I am currently using these tools to characterize dissolved organic Fe compounds exported from coastal wetlands to continental margins, which are among the most biologically productive regions of the ocean. Dissolved Fe (Iron) is an essential micronutrient and fuels this productivity, yet it is extremely scarce in the ocean due to its low inorganic solubility. As the interface between terrestrial and marine systems, coastal wetlands are a source of DOM and Fe to seawater. However, the concentration and composition of DOM and dissolved organic Fe that are released from coastal wetlands are largely unknown. The tools I am developing with EMSL support will allow us to form a molecular picture of DOM and DOM-Fe species derived from coastal wetlands and, further, to assess the role of coastal wetlands in controlling the distribution of dissolved organic Fe species across the global coastal ocean. Understanding the molecular composition and distribution of dissolved organic Fe species in the coastal ocean is essential for predicting biological productivity in these regions, which exert a major influence on the global carbon cycle.  

 What university did you join us from? 

 I am currently a postdoctoral fellow at Oregon State University.  

 What do you enjoy doing in your free time? 

I enjoy mountain biking and trail running. It’s been fun discovering trails around Corvallis, OR, where I currently live. 

Anna Bennett 

Anna Bennett is a postdoctoral researcher working with principal investigator Davinia Salvachua-Rodriguez of the National Renewable Energy Laboratory (NREL) on a Large-Scale EMSL Research project, "Understanding simultaneous lignin depolymerization and catabolism in white-rot fungi." Through the project, Bennett and Salvachua-Rodriguez are working with EMSL’s Functional and Systems Biology science area and, more specifically, the Biomolecular Pathways Integrated Research Platform. The project funding allows access to instrumentation, including nuclear magnetic resonance, mass spectrometers, and multiple sequencers. 

What is your research area?  

We are interested in a particular group of fungi that are commonly found growing on dead trees in the wilderness. These fungi (called white and brown rot fungi) break down a complex carbon molecule, called lignin, that has huge industrial applications. We aim to understand how these fungi break down and incorporate lignin and how we can engineer them to break down other industrial compounds like plastics.  

Why did you want to be a scientist? 

I think I sort of became a scientist on accident. I didn’t realize it was a career option until probably late in my undergraduate degree, as I was the first in my immediate family to attend college. I always enjoyed asking questions about nature and found myself in an undergraduate research position that set up the rest of my scientific journey. Now I love being a scientist because I get to explore the unknowns in nature, a place where I enjoy spending my free time. 

What big challenge do you hope to tackle during your career? 

In grad school, I studied the bacteria in the Yellowstone National Park hot springs. At NREL, I am using similar techniques and applying them to white rot fungi, which have very different biology than bacteria, so this has presented a huge challenge, but I am thrilled to expand my microbiology knowledge to fungi. 

When did you become an EMSL user and can you explain the potential impact for your research? 

I started at NREL about two months ago, but I am taking over a project from a former member of the lab, Teeratas Kijpornyongpan, who has been instrumental in both the data acquisition and analyses. To understand the metabolism of white rot fungi, we combine sequence and metabolite data to determine the organisms’ activity under changing environmental conditions. EMSL is integral in both the processing and analysis of these highly complex datasets.  

What university did you join us from? 

I completed my PhD at the University of Minnesota (2022) and my undergraduate degree at the University of Dayton (2016).  

What do you enjoy doing in your free time? 

In my free time, I like to hike with my dog, trail run, mountain bike, cook, hang out with family / friends, and watch sports.