Jennifer Bhatnagar

Current Research

We study the ecology, chemistry, and biology of microorganisms in the environment. Microbes are the engines of carbon and nutrient cycling through ecosystems. The goal of our research is to uncover the biochemical mechanisms that microbes use to drive these large-scale processes. To do this, we use a combination of biochemical analyses and sequencing technologies to identify direct, mechanistic links between the genetic architecture, community structure, and biochemical functions of microbes in complex environments. We focus on organisms in Kingdom Fungi, because they are directly responsible for moving energy and elements between the biosphere and the atmosphere, but are less well understood than plants, animals, and bacteria. Fungi also make beautiful macrostructures that have a long and interesting history in human society, and now are also aiding us in new studies of molecular-level fungal processes in the environment.

Current research includes: 1) Molecular mechanisms and biogeochemical consequences of fungal species interactions. Diversity of decomposer microorganisms often has positive or negative effects on total decay rates. These patterns can arise from synergistic and antagonistic interactions between decomposer species, yet we still do not have a mechanistic understanding of the biological processes that determine the outcome of these interactions or their influence on ecosystem-level biogeochemistry. We are identifying the molecular-level factors that regulate these processes using a combination of -omics, modeling, and community ecology approaches. 2) Secretomes of plant-fungal interactions. Mycorrhizal fungi are a ubiquitous group of fungi that associate symbiotically with live plant roots, providing nutrients and water to plants in exchange for sugar. Mycorrhizal fungi associate with over 90% of plant families, yet we still know little about the molecular basis of functional diversity among different mycorrhizal species. Our research uses new analytical chemistry techniques to quantify, visualize, and map the biochemical processes that mycorrhizal fungi use to acquire nutrients and transform the soil environment. 3) Resistance and resilience of microbial guilds and biogeochemical functions to climate change. This project aims to link ecosystem changes to the microbial communities that may drive them. At its core, the project is examining the responses of plant growth and soil biogeochemistry to rapid climate-induced changes in the Northeastern U.S. We are characterizing the microbial community drivers of these ecosystem responses through identification of total microbial community composition, active microbial communities, and genomic relationships between microbial stress tolerance and biogeochemical function.

Selected Publications

• Hoeksema, J, Averill C, Bhatnagar JM, Brzostek E, Buscardo E, Chen K-H, Liao H-L, Nagy L, Policelli N, Ridgeway J, Vilgalys R (2020) Ectomycorrhizal plant-fungal co-invasions as natural experiments for connecting plant and fungal traits to their ecosystem consequences. Frontiers in Forests and Global Change 3: 84.
• Garcia MO, Templer PH, Sorensen PO, Sanders-Demott R, Groffman PM, Bhatnagar JM (2020) Soil microbes trade-off biogeochemical cycling for stress tolerance traits in response to year-round climate change. Frontiers in Microbiology 11: 616.
• Vivelo A, Bhatnagar JM (2019) Meta-analysis of fungal succession during plant litter decay. FEMS Microbiology Ecology 95: fiz145.
• Averill C, Cates L, Dietze MC, Bhatnagar JM (2019) Spatial vs. temporal controls over soil fungal community similarity at continental and global scales. ISME Journal 13: 2082–2093.
• Averill C, Dietze MC, Bhatnagar JM (2018) Continental scale nitrogen pollution has shifted forest mycorrhizal associations, driving losses of soil carbon. Global Change Biology 00: 1-10.
• Bhatnagar JM, Peay KG, Treseder KK (2018) Litter chemistry influences decomposition through activity of specific microbial functional guilds. Ecological Monographs 88: 429-444.
• Siletti C, Zeiner CA, Bhatnagar JM (2017) Distributions of fungal melanin across species and soil. Soil Biology and Biochemistry 113: 285-293.