About

Satish C. Myneni is a Professor of Geosciences at Princeton University, specializing in molecular environmental geochemistry. He is part of the Geochemistry group within the Department of Geosciences. His research areas include environmental geochemistry, chemistry of mineral-water and bacteria-water interfaces, aqueous speciation, ion solvation and complexation, the chemistry of iron in terrestrial and marine systems, organic biogeochemistry, and the chemistry of natural organohalogens. Myneni's work focuses on understanding chemical processes at interfaces and in natural systems, contributing to the broader understanding of geochemical interactions in environmental contexts.

Research topics

• Chemistry
• Environmental chemistry
• Chromatography
• Geology
• Ecology
• Biology
• Earth science
• Biochemistry
• Environmental science
• Inorganic chemistry
• Soil science
• Organic chemistry

Selected publications

• Probing Nanoscale Chemical Environments of Zinc in Diatoms

  Analytical Chemistry · 2025-11-04

  articleSenior author

  Diatoms impact the biogeochemical cycling of zinc (Zn) due to elevated cellular Zn levels over other phytoplankton, and their strong biological uptake of Zn in the Southern Ocean sets the global distribution of Zn in ocean water columns. Past studies have revealed the abundance and spatial distribution of Zn in individual diatoms, while others have shown diverse Zn chemical species in whole-cell aggregates. However, intracellular and intercellular variations in Zn chemical forms remained unknown. For the first time, we applied a synchrotron X-ray nanoprobe to cultured diatoms (Phaeodactylum tricornutum and Chaetoceros muelleri) and resolved spatial heterogeneities of Zn chemistry. The result shows the partitioning of Zn between intracellular contents (soft parts) and frustules (mainly in the intracellular contents for P. tricornutum and similar Zn concentrations in the intracellular contents and frustules for C. muelleri). We found multiple Zn chemical species unevenly distributed within individual cells, where Zn–phosphoryl complexes were the most abundant followed by cysteine, histidine, biogenic silica, and carboxyl complexes. Cellular Zn species varied between individual organisms and were influenced by Zn availability. To our knowledge, this work presents the first X-ray measurements of trace metal speciation at sub-100 nm resolution in biological samples in their natural state. This research improves our ability to examine the biogeochemistry of Zn on the nanoscale and can help us understand the role of Zn in plankton growth and the Zn cycle in ocean waters.

  PublisherDOI

• Divalent Cations Influence the Composition of Adsorbed Organic Carbon on Mineral Surfaces: A Comparative Study of Clay Minerals and Metal Oxides

  2025-01-01

  article
  PublisherDOI

• Distinct microbiomes underlie divergent responses of methane emissions from diverse wetland soils to oxygen shifts

  ISME Communications · 2025-01-01 · 3 citations

  articleOpen access

  Abstract Hydrological shifts in wetlands, a globally important methane (CH4) source, are critical constraints on CH4 emissions and carbon-climate feedbacks. A limited understanding of how hydrologically driven oxygen (O2) variability affects microbial CH4 cycling in diverse wetlands makes wetland CH4 emissions uncertain. Transient O2 exposure significantly stimulated anoxic CH4 production in incubations of Sphagnum peat from a temperate bog by enriching for polyphenol oxidizers and polysaccharide degraders, enhancing substrate flow toward methanogenesis under subsequent anoxic conditions. To assess whether shifts in soil microbiome structure and function operate similarly across wetland types, here we examined the sensitivity of different wetland soils to transient oxygenation. In slurry incubations of Sphagnum peat from a minerotrophic fen, and sediments from a freshwater marsh and saltmarsh, we examined temporal shifts in microbiomes coupled with geochemical characterization of slurries and incubation headspaces. Oxygenation did not affect microbiome structure and anoxic CH4 production in mineral-rich fen-origin peat and freshwater marsh soils. Key taxa linked to O2-stimulated CH4 production in the bog-origin peat were notably rare in the fen-origin peat, supporting microbiome structure as a primary determinant of wetland response to O2 shifts. In contrast to freshwater wetland experiments, saltmarsh geochemistry—particularly pH—and microbiome structure were persistently and significantly altered postoxygenation, albeit with no significant impact on greenhouse gas emissions. These divergent responses suggest wetlands may be differentially resistant to O2 fluctuations. With climate change driving greater O2 variability in wetlands, our results inform mechanisms of wetland resistance and highlight microbiome structure as a potential resiliency biomarker.

  PublisherDOI

• Kinetics of Clay Mineral Formation in Weathering Environments: From Aqueous Solutions to Crystals

  2025-01-01

  article1st authorCorresponding
  PublisherDOI

• SYnergy of Soft and Tender X-rays for Earth Research (SYSTER)

  2024-01-01

  articleOpen access
  PublisherOA PDFDOI

• Role of Fe in the Breaking and Making of Natural Organic Molecules

  2024-01-01

  articleOpen access1st authorCorresponding
  PublisherOA PDFDOI

• Biogenic-to-lithogenic handoff of particulate Zn affects the Zn cycle in the Southern Ocean

  Science · 2024-06-13 · 14 citations

  articleSenior authorCorresponding

  Zinc (Zn) is vital to marine organisms. Its active uptake by phytoplankton results in a substantial depletion of dissolved Zn, and Zn bound to particulate organic matter replenishes dissolved Zn in the ocean through remineralization. However, we found that particulate Zn changes from Zn bound to phosphoryls in cells to recalcitrant inorganic pools that include biogenic silica, clays, and iron, manganese, and aluminum oxides in the Southern Ocean water column. The abundances of inorganic pools increase with depth and are the only phases preserved in sediments. Changes in the particulate-Zn speciation influence Zn bioavailability and explain the decoupling of Zn and phosphorus and the correlation of Zn and silicon in the water column. These findings reveal a new dimension to the ocean Zn cycle, implicating an underappreciated role of inorganic Zn particles and their impact on biological productivity.

  PublisherDOI

• Detecting Structural Environments of Carboxyl Groups in Dissolved Natural Organic Molecules

  ACS ES&T Water · 2024-01-11 · 19 citations

  articleSenior authorCorresponding

  The carboxyl group is one of the most abundant and important functional groups in natural organic molecules (NOM). Its structural environment determines its reactivity and stability and has been examined previously using Fourier-transform infrared spectroscopy (FTIR), specifically the asymmetric stretch of the deprotonated carboxylate group. In this study, we provide a comparative analysis of the carbonyl stretch of the protonated carboxyl group (ν(C═O)carboxyl) and show that it is useful for the detection of carboxyl structural environments where ambiguity exists. When compared to model carboxylic acids, the ν(C═O)carboxyl frequency of dissolved NOM from various locations and climatic conditions shows a narrow distribution in 1720–1732 cm–1. The majority of carboxyls in NOM are α-substituted (hydroxyl, ether, ester, ketone, carboxyl, etc.) aliphatic carboxylic acids, agreeing with previous studies. Additionally, the ν(C═O)carboxyl frequency, as suggested here, provides a greater distinction between aliphatic and aromatic carboxylic acids and is better suited for peptide-rich biological samples. Environmental water samples often contain high salt concentrations that interfere with the detection of carboxyls. Solid-phase extraction using PPL cartridges is an efficient desalting method and can be applied to organic-poor salt-rich samples for proper FTIR analysis.

  PublisherDOI

• Bromine contamination and risk management in terrestrial and aquatic ecosystems

  Journal of Hazardous Materials · 2024-02-24 · 36 citations

  reviewOpen access
  PublisherOA PDFDOI

• A Friend or a Foe: Role of Minerals in the Organic Carbon Dynamics and the C-Cycle

  2024-01-01

  articleOpen access1st authorCorresponding
  PublisherOA PDFDOI

Recent grants

• Collaborative Research: The chemistry of lignin's photochemical transformation in the environment: implications for global carbon cycling

  NSF · $330k · 2016–2021

• Collaborative Research: Highly reactive thiol binding sites on bacterial cell envelopes and their influence on metal speciation in aquatic systems

  NSF · $120k · 2015–2019

• Collaborative Research: Halocarbon Biogeochemistry in Coastal Wetland Ecosystems - Exploring the Transition from Forested Wetland to Salt Marsh

  NSF · $90k · 2015–2018

Frequent coauthors

• Anders Nilsson

  Stockholm University

  56 shared

• Lars‐Åke Näslund

  50 shared

• Lars G. M. Pettersson

  Stockholm University

  49 shared

• Hirohito Ogasawara

  SLAC National Accelerator Laboratory

  49 shared

• Philippe Wernet

  Uppsala University

  47 shared

• Alessandra C. Leri

  Marymount Manhattan College

  37 shared

• Matteo Cavalleri

  32 shared

• D. C. Edwards

  30 shared

Labs

• Molecular Environmental Geochemistry GroupPI