Corroding microbes present a significant and expensive threat to industries that depend on concealed and underground iron structures, such as sprinklers and oil pipelines. A recent investigation reveals insights into the processes behind microbial-induced corrosion (MIC), which could aid in damage prevention.
In oxygen-free conditions, pipelines, sprinklers, and other infrastructures are at risk of Microbially Induced Corrosion (MIC). This phenomenon involves microorganisms that deteriorate iron-based structures, which can result in substantial repair costs or even catastrophic failures.
Unlike traditional rust, which forms through a chemical reaction with oxygen, MIC occurs in environments devoid of oxygen. The microbes responsible feed on the iron directly, triggering a harmful reaction that compromises the material’s integrity. This type of corrosion costs trillion in losses each year across various industries, particularly in oil and gas. Therefore, recognizing and managing the microbial processes leading to corrosion is crucial.
Recently, microbiologists Dr. Satoshi Kawaichi and Professor Dr. Amelia-Elena Rotaru from the University of Southern Denmark have revealed new insights regarding how a specific strain of the species Methanococcus maripaludis efficiently causes iron corrosion. Their research received funding through a Sapere Aude grant from the Danish Independent Research Fund and has been published in npj Biofilms and Microbiomes.
This study challenges the common belief that these microbes secrete enzymes into their surroundings to facilitate iron corrosion, enabling them to extract nutrients for growth. Instead, the researchers found that the microbes adhere directly to the iron surface, utilizing sticky enzymes present on their cell walls to obtain the necessary nutrients without expending energy on releasing enzymes that might not make it to the iron.
After latching onto the iron, the microbes initiate corrosion, quickly forming a black film on the surface.
Dr. Kawaichi explains, “The microbes swiftly form pits beneath this black layer, leading to significant damage within a few months. In fact, 5-gram pieces of iron can deteriorate into a black powder visible to the eye within just one or two months.”
A Dual Environmental Challenge
The researchers note that such microbial evolution showcases how microbes adapt and flourish in human-created settings. In this situation, Methanococcus maripaludis has evolved to utilize iron structures efficiently for energy and sustenance.
This microbial adaptation brings not only economic challenges but also environmental consequences:
“These organisms are methanogenic, which means they produce methane. Methane is a significant greenhouse gas, and it raises concerns that microbes adapting to artificial environments are generating methane more effectively. This evolution could lead to increased methane emissions,” states Dr. Amelia-Elena Rotaru.
Methane-producing microbes can also thrive on various mineral particles released into the environment due to climate change and human activities. These particles originate from several sources, including industry, agriculture, forest fires, river runoffs, and melting glaciers, and may enhance certain methane-producing microbial activities.
Members of Dr. Rotaru’s team are currently exploring glacier melt particles from Greenland to determine their effect on atmospheric methane emissions.
Dr. Amelia-Elena Rotaru holds a European Research Council Consolidator Grant for a project titled “Conductive Minerals as Electrical Conduits in Methane Cycling” and has received a Novo Nordisk Rising Investigator Award that investigates how certain methanogens can transform CO2 and electricity into methane.
Amelia-Elena Rotaru serves as a Professor and Head of Research at the Department of Biology at the University of Southern Denmark. Her research is supported by the Danish Research Council for Independent Research, the Novo Nordisk Foundation, and a European Research Council Consolidator Grant.
