Microbes That Stick Together Corrode Together

December 3, 2018 • By Sara Carney, Contributing Author

We all know about the harm some microbes can cause to our bodies. But that’s not the only thing that microbes can damage. Microorganisms in machinery and places like oil and gas production facilities can cause wreak havoc on these systems. In fact, microbes are responsible for 20 to 50 percent of all damage to equipment caused by corrosion, according to the National Association of Corrosion Engineers, leading to annual costs of more than $1.5 trillion worldwide.

To help solve this problem, Nalco Champion, an Eco-Lab Company, is leveraging the International Space Station (ISSInternational Space Station) National Lab to investigate the most basic characteristics of biofilms and what makes them cause corrosion. This pioneering study is slated for launch on SpaceX’s 16^th Commercial Resupply Services mission(Abbreviation: CRS mission) A CRS mission is a cargo resupply mission contracted by NASA to deliver supplies and research to the International Space Station on commercial spacecraft as part of the CRS contract with three commercial companies. As part of CRS missions, experiments currently return to Earth on SpaceX Dragon spacecraft that splash down in the ocean. and is one of more than 20 ISS National Lab investigations on this mission.

How Microbes Cause Damage

Microbes can corrode materials through the formation of biofilms, which include accumulations of microorganisms within a self-made matrix of extracellular polymeric substances (EPS). In biofilms, microbes stick to each other and the materials they generate.

Although not all biofilms are corrosive, many are. This is known as microbially influenced corrosion (MIC), which speeds up corrosion in iron and steel.

Oil and gas production facilities are particularly vulnerable to biofilm formation because microbes feed on the nutrients found there. MIC can create pits in pipelines and ruin equipment. In some cases, the damage can be extensive enough to cause pipeline failure or an oil spill. MIC can even be found in environments without oxygen, such as deep-sea pipelines, where, in lieu of oxygen, microbes are able to survive on the sulfates and nitrates present in oil.

What Can Be Done

The most common way to treat biofilms is known as “pigging.” This process involves two components: mechanical cleaning and use of a biocide (a substance that inhibits the growth of living organisms). It’s essential to do both because biofilms confer resistance against biocides. However, even with this process, there is still room for improvement, and researchers have much to learn about biofilms and MIC to truly mitigate their effects.

Vic Keasler and Renato De Paula of Nalco Champion are seeking answers to persisting MIC questions, such as: How do biofilm thickness and cellular activity impact corrosion? The team will study biofilms on the ISS National Lab and on Earth, examining the thicker biofilms grown in microgravityThe condition of perceived weightlessness created when an object is in free fall, for example when an object is in orbital motion. Microgravity alters many observable phenomena within the physical and life sciences, allowing scientists to study things in ways not possible on Earth. The International Space Station provides access to a persistent microgravity environment. to understand how the thickness of the biofilm impacts the rate of corrosion. The study will also help elucidate what leads to biofilms causing corrosion in the first place—because not all biofilms do.

“We know biofilm growth in microgravity is significantly increased,” Keasler said in a press release. “By comparing that biofilm growth and biofilms grown in normal Earth gravity, we can understand the impact of film thickness on corrosion without the variable of time.”

Ultimately, this work could also lead to the development of a more effective biocide to mitigate MIC. Such advances could help protect more equipment, reduce costs, and avoid potential disasters.

“This is a multi-billion-dollar challenge each year across the oil and gas industry,” Keasler said. “Through this experiment, we’re attempting to fill a critical knowledge gap in the industry to identify optimal biocide dosage rates and timing based on biofilm thickness and levels at which corrosion initiates.”