USC.edu
Hutchins Lab

Trace Metal Uptake & Nutrient Cycling

February 24, 2026

Trace metals such as iron, cobalt, nickel, and zinc are essential for marine microbial life. At the Hutchins-Fu Lab, we investigate how phytoplankton and nitrogen-fixing organisms acquire and regulate trace metals, how environmental stressors modify metal bioavailability, and how these processes influence large-scale nutrient cycling and climate regulation.

Focus Areas

1. Iron Limitation in Phytoplankton Physiology
Iron is a key component of enzymes involved in photosynthesis, nitrogen fixation, and nutrient transport. Much of our research explores how iron scarcity constrains microbial growth and metabolism, especially in high-nutrient, low-chlorophyll regions.

  • 2024 Nature Geoscience and 2023 Biogeosciences papers highlighted how iron availability shapes phytoplankton productivity and carbon cycling.

  • 2024 Frontiers in Microbiology showed how Synechococcus strains acclimate differently to iron-limited conditions depending on their ecotype.

2. Trace Metal Co-Limitation and Nutrient Interactions
We study how trace metal limitation interacts with other nutrient stresses (e.g., phosphorus, nitrogen) to drive microbial competition and metabolic adaptation.

  • 2022 ISME Journal: Molecular responses in Crocosphaera to co-limitation by iron and phosphorus reveal tightly linked gene regulation pathways.

  • 2024 Earth-Science Reviews: Our team evaluated the complexities and risks of stimulating productivity through artificial iron fertilization.

3. Olivine Dissolution and Ocean Alkalinity Enhancement
Olivine weathering releases trace metals into seawater. We assess how these dissolution products affect phytoplankton communities and microbial carbon cycling.

  • 2023 Biogeosciences and 2024 Science of the Total Environment: Our lab studied how olivine-derived trace metals impact carbon uptake and biological responses under future ocean scenarios.

4. Kinetic Isotope Effects in Metal Redox Reactions
In collaboration with geochemists, we explore how phytoplankton and abiotic processes fractionate isotopes during Fe(III) reduction.

 

  • 2024 Geochemistry, Geophysics, Geosystems: Findings revealed contrasting isotope effects between biological and chemical pathways, with implications for metal tracking in ocean systems.