New publication in Geomicrobiology Journal explores how microbes could help build a greener future for iron mining

Iron is essential for modern society, forming the basis of steel used in infrastructure, transportation, and manufacturing. However, traditional iron processing is energy intensive and contributes substantially to global carbon emissions. At the same time, high-grade iron ores are becoming increasingly scarce. 

This study probes how Pseudomonas aeruginosa mobilizes iron from ferrihydrite, goethite, hematite, basalt glass, and crystalline basalt, chosen to reflect critical oxide ores such as laterites. In iron limited medium, minerals and rocks were incubated in sterilized Teflon flasks with the bacterium. Researchers found that the bacteria can switch between different iron-acquisition strategies depending on how accessible the iron is. Even more remarkably, bacterial cells communicate with one another through quorum sensing, coordinating their behaviour to maximize iron uptake under nutrient-poor conditions. 

These findings improve our understanding of how microbes interact with minerals and could eventually support the development of biomining technologies capable of recovering metals from low-grade ores and mine waste with a significantly lower environmental footprint.
As demand for metals continues to rise during the global energy transition, harnessing microbial processes may become an important component of future sustainable mining practices.

The paper “Microbial Strategy Shift for Releasing Iron with Varying Mineral Substrates and their Accessibility: Implications for Iron Biomining” is co-authored by Anita J Brijit (EDGE, CeMESS, University of Vienna) along with Piyush Sriwastava (Indian Institute of Technology Bombay, University of Oxford), Bablesh Ranawat (IIT Bombay), Bhagyashree Mishra (IIT Bombay, University of Geneva), Divyadeep Harbola (IIT Bombay), and George Mathew (IIT Bombay).