Within a pine forest located in Michigan’s Upper Peninsula, the sole functioning nickel mine in the United States is approaching the conclusion of its operational life. With car manufacturers seeking the metal for batteries in electric vehicles, the nickel yield at Eagle Mine is diminishing and may soon fall below levels that justify continued extraction.
However, earlier this year, the mine’s proprietor initiated trials of a novel method that could extract additional nickel. Inside two shipping containers recently set up at the mill of the mine, a broth produced through fermentation and developed by the startup Allonnia is combined with concentrated ore to extract and eliminate impurities. This technique facilitates nickel extraction from ore of lower quality.
Kent Sorenson, chief technology officer at Allonnia, states that this strategy could assist companies in maintaining operations in sites like Eagle Mine that have exhausted their prime ore. “The low-hanging fruit is to keep mining the mines that we have,” he notes.
The rise in demand for nickel, copper, and rare earth elements is swift, driven by the rapid expansion of metal-heavy data centers, electric vehicles, and renewable energy initiatives. Nevertheless, the extraction of these metals is becoming increasingly challenging and costly as miners have already tapped into the most optimal resources. Similar to the traditional method of squeezing the end of a toothpaste tube, Allonnia’s broth is among several biotechnological approaches that could assist miners in extracting additional metal from aging mines, subpar ore, or waste heaps.
The mining sector has intentionally introduced microbes to copper ore for many years. At existing bioleaching sites for copper, miners stack crushed copper ore into mounds and apply sulfuric acid. Bacteria that thrive in acidic environments, such as Acidithiobacillus ferrooxidans, inhabit the piles. A substance produced by these organisms breaks the bond between sulfur and copper molecules, enabling the release of the metal.
Up to now, aside from maintaining acidity and aerating the heap, there was little more miners could do to stimulate microbial proliferation. However, Elizabeth Dennett, CEO of the startup Endolith, claims that the declining costs of genetic tools are enabling more proactive management of microbial populations within a heap. “The technology we’re employing now wasn’t available a few years back,” she states.
Endolith examines fragments of DNA and RNA present in the copper-rich solution that drains from an ore heap to identify the microbes dwelling within. Paired with a range of chemical analyses, this information aids the company in deciding which microbes to distribute on a heap to enhance extraction.
In laboratory tests conducted on ore from mining company BHP, Endolith’s interactive techniques surpassed traditional passive bioleaching methods. In November, the company secured $16.5 million to transition from its lab in Denver to active mine heaps.
Despite these encouraging initial findings, Corale Brierley, an engineer with decades of experience in metal bioleaching systems since the 1970s, doubts whether companies like Endolith that introduce additional microbes to ore will be able to effectively scale their processes. “What guarantees can you provide the company that those organisms will actually thrive?” Brierley inquires.
Large mining corporations that have already optimized every aspect of their processes will also be tough to persuade, asserts Diana Rasner, an analyst specializing in mining technology for the research firm Cleantech Group.
“They are acutely aware of what it takes to scale these technologies because they understand the industry,” she remarks. “They’ll be your staunchest advocates, but they’ll also be your harshest critics.”
Along with technical hurdles, Rasner emphasizes that biotechnology startups backed by venture capital will find it difficult to deliver the rapid returns that investors are looking for. Mining firms desire extensive data before implementing a new method, which could necessitate years of testing. “This isn’t software,” Rasner states.
Nuton, a subsidiary of the mining behemoth Rio Tinto, serves as a notable example. The company has been developing a copper bioleaching technique utilizing a combination of archaea and bacteria strains alongside chemical additives for decades. However, it only began demonstrating the technology late last year at a site in Arizona.
While both Endolith and Nuton employ naturally occurring microbes, the startup 1849 aims to achieve a greater performance enhancement by genetically modifying microbes.
“You can opt for the traditional methods used by mining companies,” remarks CEO Jai Padmakumar. “Or you can attempt the ambitious route and engineer them. If successful, the payoff is significant.”
Genetic modification would enable 1849 to customize its microbes to the specific issues a customer faces. However, Buz Barstow, a microbiologist from Cornell University studying biotechnology applications in mining, cautions that altering organisms can make them more challenging to cultivate.
Other companies are attempting to sidestep that trade-off by utilizing the byproducts of microbial fermentation instead of live organisms. Alta Resource Technologies, which concluded a $28 million investment round in December, is engineering microbes that produce proteins capable of extracting and isolating rare earth elements. Similarly, the startup REEgen, based in Ithaca, New York, employs the organic acids generated by a modified strain of Gluconobacter oxydans to extract rare earth elements from ore and waste materials such as metal recycling slag, coal ash, or obsolete electronics. “The microbes serve as the manufacturing agents,” says CEO Alexa Schmitz, a former student of Barstow’s lab.
To address the surging demand for metals, this new wave of biotechnological innovations must extend beyond copper and gold, asserts Barstow. In 2024, he initiated a project to identify genes that could be effective in extracting and separating a broader assortment of metals. Despite the challenges ahead, he argues that biotechnology holds the promise to revolutionize mining as fracking did for natural gas. “Biomining is one of those fields where the need … is substantial,” he states.
The primary challenge will be moving swiftly enough to meet the rising demand.
