Microbes That Breathe Rust Could Help Save Earth’s Oceans
London-UK, November 12, 2025
In a critical development blending marine biology and climate science, researchers have identified a unique class of deep-sea microbes that effectively “breathe rust” by consuming iron oxides, a process that is now being studied as a potential, groundbreaking tool to help restore the health of Earth’s increasingly threatened oceans.
These extraordinary organisms, belonging to the Marinobacter family, survive in the oxygen-depleted zones of the deep ocean by using iron oxide (rust) in their respiration cycle instead of oxygen.
Scientists propose that harnessing the ability of these rust-reducing microbes could be essential in reversing the widespread damage caused by ocean acidification and deoxygenation, offering a scalable, natural solution to mitigate the devastating impacts of climate change on marine ecosystems worldwide.
Key Headlines
Rust Respiration:
The microbes use iron oxide (rust) in the place of oxygen for their respiration, thriving in the vast, oxygen-minimum zones of the deep ocean.
Nutrient Restoration:
The microbes’ metabolic process releases crucial trace metals and phosphorus—nutrients that are often locked up in the deep sea but are essential for fueling phytoplankton growth in surface waters.
Surface Fix:
By releasing these nutrients, the process could help stimulate the growth of phytoplankton, which are vital for absorbing CO_2 from the atmosphere and producing oxygen.
Geoengineering Potential:
Researchers are cautiously exploring the use of these microbes as a form of “biogeoengineering,” a natural way to enhance the ocean’s biological carbon pump and restore coastal ecosystem health.
The discovery focuses on a group of microbial organisms that thrive in the deep ocean, often in vast areas known as Oxygen Minimum Zones (OMZs), which are expanding globally due to climate change. OMZs are areas where ocean oxygen levels are so low that most conventional marine life, including fish, cannot survive.
In these hostile environments, these newly studied Marinobacter species have evolved a unique metabolic trick: they use iron oxide (rust) as their final electron acceptor in respiration, much like humans use oxygen. This process is known as Dissimilatory Iron Reduction (DIR).
The significance of this microbial breathing goes beyond mere survival. The iron oxide that the microbes consume is inert, locking up essential trace metals and nutrients in deep-sea sediments.
When the microbes “breathe” the rust, their metabolic process chemically alters the iron oxide, which then releases vital nutrients back into the water column. Specifically, it releases crucial phosphorus and bioavailable iron, which are the two most common limiting nutrients for ocean life.
The potential application of this discovery lies in surface waters. The vast, open ocean surface is often a biological desert due to a lack of iron and phosphorus, which are necessary to fuel the growth of phytoplankton.
Phytoplankton are the microscopic, plant-like organisms at the base of the marine food web, and critically, they are responsible for absorbing massive amounts of atmospheric Carbon Dioxide (CO_2) through photosynthesis—a process called the biological carbon pump.
Scientists are now exploring controlled scenarios where the microbial activity can be harnessed to increase the flux of these essential nutrients from the deep sea into surface waters.
By stimulating natural phytoplankton blooms, they believe they could enhance the ocean’s capacity to absorb CO_2 from the atmosphere and simultaneously restore the health of depleted coastal ecosystems that rely on these basic nutrients.
The long-term goal is to use this natural biological process to slightly enhance the efficiency of the ocean’s natural carbon sequestration mechanism.
However, researchers are proceeding with caution. The concept of biogeoengineering—deliberately manipulating natural systems to mitigate climate change—carries significant ethical and ecological risks. Any large-scale intervention in the deep sea could have unintended consequences for existing microbial communities and deep-sea ecosystems.
Therefore, the current research is strictly focused on understanding the precise chemical and biological processes and simulating the potential impact under carefully controlled conditions. The rust-breathing microbes offer a glimpse into a powerful, natural climate solution, provided humanity can learn to collaborate with nature responsibly.
