At an old steel site in Pittsburgh, bacteria evolved to survive – and eat – industrial pollution
Decades of pollution at Pittsburgh brownfields left bacteria that evolved to survive it – and maybe help clean up contaminated soil.
In Pittsburgh, a city steeped in industrial history, former steel sites have been repurposed into vibrant neighborhoods, research centers, and technology hubs. However, beneath these revitalized landscapes, a unique transformation has been quietly occurring for decades.
Brownfields, often defined by contaminated soil, pose challenges for redevelopment due to pollution. Yet, these sites remain dynamic ecosystems, teeming with billions of microorganisms that have evolved to survive and even thrive amidst industrial contaminants.
As a microbiologist at Carnegie Mellon University, I have delved into this intriguing phenomenon through a brownfield located just two miles from Hazelwood Green, a former steelmaking site that once employed thousands and contributed to Pittsburgh's Steel City reputation. Once a hub of industrial activity, this area now serves as a case study for understanding the resilience and adaptability of microbial life in the face of pollution.
The site's soil, contaminated with petroleum hydrocarbons, heavy metals, and other pollutants, including benzene, toluene, ethylbenzene, and xylene (BTEX), presents a unique ecological challenge for microorganisms. While many organisms may be toxic to such pollutants, some bacteria possess metabolic pathways that allow them to tolerate or even consume these substances as food, providing a survival advantage.
My lab has been collecting soil samples from various parts of Hazelwood Green, spanning different historical levels of contamination. By examining these samples through metagenomic sequencing, we aim to identify the microbial communities present and understand the genes associated with the degradation of BTEX and other hydrocarbons. This approach allows us to compare microbial abundance across different locations and depths, revealing the lasting impact of past pollution on these communities.
To further validate our findings, we isolate bacteria from the site and test whether they can utilize individual pollutants as food. In a lab setting, we grow these bacteria in a minimal medium containing only the pollutant as the sole carbon source, mimicking the conditions they would encounter in the contaminated soil. If the bacteria thrive, it indicates that they can indeed utilize the pollutant for growth and survival, effectively "eating" the contamination.
This ongoing research not only sheds light on the remarkable adaptability of microorganisms in polluted environments but also holds the potential to inform future efforts in brownfield remediation. By understanding how microbes have evolved to cope with industrial pollution, we may uncover novel strategies to enhance the clean-up processes and create safer, more sustainable environments in our revitalized urban landscapes.
Written by urgent.news from The Conversation's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
