The power of microbes

Cemvita is working toward a biomining future where nature's existing processes are harnessed to extract the essential minerals and metals that power our everyday lives. This image depicts Cemvita's use of bio-lixiviants to extract metals through a heap leach process, as well as a future of in situ mining. In situ mining could leave the surface undisturbed while bio-lixiviants are pumped underground to leach target metals subsurface.

The Cemvita team at the inaugural Cemvita Day in Houston in August 2022. In the center behind the lectern are Cemvita Cofounder and Chief Executive Officer Moji Karimi, Cofounder and Chief Science Officer Tara Karimi, and Mining Biotech Vice President Marny Reakes.

A bioreactor cultivates microbes in Cemvita's laboratory.

Cemvita's laboratory in Westminster, Colorado.

In an office building in Westminster, Colorado, just north of Denver, a group of scientists and engineers are working with many billions of coworkers — microscopic microbes — to develop mining processes that are better for the environment and also more cost effective.

Many vials of solution of various colors are constantly swirled by machines while people work on studying the solutions to determine the right groups of microbes to do the work which needs to be done at mine sites.

Cemvita was launched in Houston in 2017 by brother and sister Moji Karimi, an engineer and energy entrepreneur, and Dr. Tara Karimi, a scientist and biotechnologist. Tara Karimi's 2018 book "Molecular Mechanisms of Autonomy in Biological Systems" discusses her concepts of code, energy and mass, which are the first three letters of Cemvita's name. "Vita" is Latin for "life."

Cemvita currently has three main focuses, which all involve using biological systems to help move us toward a renewable, clean energy future.

Their biomining business unit uses biology, chemistry and engineering to develop bio-lixiviants tailored to extract target metals from ore bodies and waste.

The GH2 portion of the company is using biotech to develop ways to put microbial solutions into depleted oil and gas reservoirs to produce a low-carbon hydrogen they call Gold Hydrogen.

Their eCO2 biomanufacturing process takes carbon dioxide from emissions sources and uses it to produce valuable materials such as fertilizer, plastics, methane and fuels. This process could also be used at mine sites to help move them toward being carbon neutral or even carbon negative while also producing new revenue streams.

Cemvita's eCO2 pilot plant opened in Houston in April 2023.

Cemvita is now a company of around 95 people, with about 25 of them in Denver. The Denver branch opened in late 2021, and much of the work on bio-mining is now done here. Visiting the offices and labs, you can sense a lot of enthusiasm for the cutting-edge work that's being done.

"It's a great company and team to work with," said Marny Reakes, Cemvita's mining biotech vice president. "I love the focus on bio-solutions for the energy transition."

She said the biomining, Gold Hydrogen and eCO2 biomanufacturing are "all three fantastic products with really great missions."

"I’m a chemical engineer with an MBA and I’ve spent the last 25 years in mining," Reakes said. "I’m really passionate about mining and the value we add to the world. The world needs metals for every aspect of our lives, there's no question about that.

"Mining companies have innovated over the years, but not fast enough to meet the needs of the energy transition, and we need a big step change."

She said part of the work they are doing in Cemvita's lab is studying ore bodies so they can design bio-lixiviants for particular ores.

"No ore body is the same, and ore bodies change, and the mineralogy changes as you get deeper in the ground or the mine plan expands," Reakes said. "So our job is to tailor the microbial recipe to leach the metals from the rock into solution. The solution can then be processed via traditional processes, such as solvent extraction electrowinning, or in the case of lithium, direct extraction or crystallization."

She said they are currently focusing on two metals critical for the energy transition – copper and lithium.

"We’re working on copper sulfide leaching, and also working on extraction of lithium from lithium clay in the Nevada and Arizona region."

She said in the future they should be able to extend these processes to other metals.

About 15% of the world's copper is currently bio-leached, Reakes said. A lot of the bio-leaching happens in Arizona and New Mexico. Cemvita is taking the next step by working with microbes to design more effective bio-lixiviants.

In some cases, as copper grades have decreased, traditional milling, flotation and smelting has become too expensive, so heap leaching is a more cost-effective solution for mining copper. Heap leaching eliminates the need to use the energy and carbon intensive process of grinding the ore into fine particles, since the coarse ore can be put right onto the leach pad.

Reakes described the microbes they work with as "super cool, hero microbes."

To explain the work that microbes do, she contrasts them with algae.

"Most people know about algae," Reakes said. "Algae take their energy from sunlight, and they take carbon for growth from CO2 in the atmosphere. These microbes also use CO2 in the atmosphere, but they get their energy not from sunlight — they get their energy from oxidizing iron and sulfur in rocks. So they actually take energy from or eat rock, and a byproduct of this is that copper or zinc, for example, is released into solution.

"So it's a very natural process. It's something that microbes do already, and mining companies started capitalizing on that about 40 years ago. What's changed since then is, about 10 years ago, there was a huge biotech revolution that changed the face of pharma, food and agriculture. It just hasn't hit mining yet.

"And that's what we’re doing, is bringing those latest biotech tools to bear to improve the speed at which the microbes extract minerals, and achieve a higher recovery."

The microbes also do some carbon sequestration as they consume carbon dioxide in order to grow.

The microbes Cemvita is using with lithium are a little different. They need to be fed with a waste carbon source such as waste from crops.

"You feed the microbes with waste crops, and then the microbes generate organic acids and other metabolites that then attack the rock and release critical minerals like lithium into the solution," Reakes said.

This process also helps to reduce carbon, because the waste crop material has sequestered carbon dioxide from the air as a feedstock.

A lot of progress has been made with Cemvita's biomining work since the company opened its Denver branch a year and a half ago.

In June 2022 Cemvita purchased Solfatara Laboratories and its facilities in Golden, Colorado, integrating Solfatara's expertise in biomining and extractive processing with the work being done at Cemvita.

"This acquisition essentially fast forwarded Cemvita's capability to scale by years and leaps us forward towards full commercial rollout in our biomining business," said Cemvita Chief Business Officer Charles Nelson.

In November 2022 Cemvita announced a partnership with Arizona Lithium Limited which will include Cemvita installing a bio-lixiviant production facility at AZL's Lithium Research Center in Tempe, Arizona. At the facility, Cemvita will do pilot testing on both tank and heap bioleaching for lithium extraction from clay or sedimentary materials.

"We will trial our bio-lixiviant with their end-to-end pilot plant, so that we can take the lithium clay all the way from being leached to a final battery-grade lithium product," Reakes said. "So that's an exciting piece of work."

Many lithium companies in the United States are working on developing lithium extraction processes specifically for their sites. Reakes said Cemvita is currently talking with several companies about lithium extraction.

"We want to bring our technology to a number of companies," Reakes said.

With their knowledge about microbes, the Cemvita team has also been providing bio-diagnostic services to mining companies. If a mining company is having issues such as hydrogen sulfide emissions or acid mine drainage, they can go to Cemvita for an analysis.

"Microbes are everywhere, so by looking at the microbial community in the tailings, in the wastewater or in the heap leach, we can advise how to optimize those communities so that you get less emissions from them, for example, or so that you get better recovery," Reakes said.

More advances in Cemvita's biomining business are on the horizon.

"We have some contracts and some other announcements that will come out in the next three to six months that I think will be very exciting," Reakes said.

While continuing to make progress with biomining, Cemvita is also researching the possibility of advancing toward in situ mining. With in situ mining, instead of digging through the ground to pull out the ore, you pump solution into the ground and let it filter through the ore and remove the target metals, and then you pump the solution back out.

"That's my ultimate goal," Reakes said. "I’ve said in some of my talks that we’re trialing our bio-lixiviants on the surface now with heap leaches and tanks, but my ultimate goal, and I think the ultimate in low impact, low footprint mining is to go in situ."

A lot of the world's uranium is mined in situ, Reakes said, because with uranium the ore body is often very contained within one area. There are also some in situ copper mines. Cemvita is researching how to safely and effectively do in situ mining with a wider variety of ore bodies.

In situ mining could have a lot of benefits – lower costs, little surface disturbance, and fewer environmental impacts. Cemvita's in-situ mining process would have even less environmental impacts than current in situ mining, because the process would use bio-lixiviants rather than pumping mineral acids underground.

"What we want to do is a much more environmentally friendly process by using microbes in situ to release just the metal ions that you want into solution and recover them," Reakes said. "So rather than creating huge open pit mines or underground mines and big tailings dams, let's just extract the metal that we need and leave the rest of the ground intact."

"We have big goals," said Renee Hodges, an environmental scientist who is Cemvita's biomining business development manager. "But we can get there."

Like the cocktails of different kinds of microbes that all work together to produce the best results, the people on the Cemvita team bring with them a wide range of knowledge and skills as they work together to move the company toward achieving its ambitious goals.

"I think the diversity of our science team here is quite remarkable," Hodges said. "We’ve got geomicrobiologists, chemists, process engineers, genomics folks, microbiologists, marine biologists, and I’ve only touched on half the skills. And they’re all very well accomplished in their own fields."

"We have people from industry and academia and a wide range of disciplines," Reakes said, "and that sort of intersection between engineering and science is where you come up with these big breakthrough discoveries on how to lower the impact of mining."

During a visit to the lab, Dr. Jaymee Fayhl-Buska, a geomicrobiologist with a PhD in geology, talked about some of the benefits of using their microbial cocktails that contain a variety of microbes. Many mines that have been using biomining methods have been working with less robust and diverse microbial communities, and that can lead to problems as conditions change.

"If anything happens, if you get too much organic carbon in your copper heap leach, then you’re out of luck, because many of the traditionally used microbes can't tolerate organic carbon molecules," Fayhle-Buska said. "But one of my microbes really loves organic carbons, so they can degrade that, and then the rest of the microbes can work a lot better."

"This is really a lot of fun," Fayhle-Buska said. "It's a great career field to be in."

The microbes the Cemvita team works with are very tiny organisms – some of the solutions at Cemvita have around three billion or more microbes per ounce. The scientists at Cemvita do DNA and RNA sequencing to identify the microbes they are working with, and to learn about the microbial communities in the various kinds of samples they receive from mine sites.

Dr. Heather Callahan, Cemvita's head of genomics, specializes in determining how to extract DNA and RNA from really difficult samples. After almost a year of working on ways to extract microbial RNA from rocks, she recently had a breakthrough.

"The joke is that I’m trying to squeeze RNA out of a rock, and that's true," Callahan said.

When other scientists try to look at RNA embedded in rocks, they usually culture it, which can change what is going on in the microbial community.

"I don't know of anyone else extracting RNA directly from mining rock," Callahan said.

Like Fayhl-Buska, Callahan said the work she is doing at Cemvita is fun.

"It's challenging," Callahan said. "I like a good challenge, though. It keeps things interesting."

"I think that's the only thing we do is challenging stuff," Hodges said. "Nothing is simple. And that's what's hard about what we do, but it also can lead to truly amazing outcomes, because we truly are looking into new fields, new horizons. It's going to be great."

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