MnDRIVE brings industry and regulators together to weigh costs, benefits, solutions.

by Mary Hoff 

What should researchers be researching? With many needs and finite resources, that’s an important question for MnDRIVE Environment, a partnership between the University of Minnesota and the State of Minnesota that brings the power of University inquiry and innovation to bear on challenges industries face related to clean air, water, and land.

In early 2020, the initiative invited private sector and state agency representatives to discuss issues in need of attention related to per- and polyfluoroalkyl substances or PFAS. This class of chemicals historically has been used in a wide spectrum of consumer goods and has since been implicated as a land and water contaminant linked to a range of health risks. Of particular concern is the fact that PFAS chemicals have started cropping up at municipal compost facilities that turn materials such as grass clippings and food waste into a nutrient-filled substance that is used to enrich soil.  

One of the businesses represented at the meeting was the Shakopee Mdewakanton Sioux Community (SMSC) Organics Recycling Facility. The facility takes in 70,000 tons of materials every year to make compost, compost blends, and landscaping mulch. It has tested its products and found PFAS levels to be well below those that the Minnesota Pollution Control Agency (MPCA) considers a health concern in residential soils. PFAS has shown up in water that drains off piles of materials that are in the process of breaking down, says MPCA composting and recycling specialist Kayla Walsh (as it has for other composting facilities around the state). The test results have facility managers looking for ways to continue to do good while preventing future problems.

The topic is a particularly hot one for SMSC because it would like to open a larger facility to meet increasing demand from community composting.

“We know composting is good. We’re amending the soil,” says SMSC biomass processing assistant manager Dustin Montey. At the same time, he adds, “we don’t want to be introducing a harmful substance back into society” by producing soil amendments containing PFAS.

Erin Skelly, environmental and compliance technician for the facility, notes that SMSC is grounded in the Native American principle of caring for the Earth with the next seven generations in mind. A participant in the 2020 MnDRIVE-hosted meeting, Skelly sees a need for research to find the source of the PFAS and how to get it out of the waste stream so it doesn’t end up in compost.

“There’s a lot that’s unknown about PFAS,” she says. “If it’s in compost and in soil, does it leach out? Does it get into groundwater? Do plants absorb that? There’s a lot of opportunity for research.”

MnDRIVE Environment funding is earmarked specifically for remediation. However, it also works upstream to stimulate discussion and connect stakeholders to collaborate on identifying and characterizing problems that remediation can help solve.

“Once we know where PFAS is and where it is coming from, then these issues can be put forward to remediate. That’s sort of the sweet spot where MnDRIVE funding programs come into play,” says MnDRIVE Environment industry and government liaison Jeff Standish.

For example, University of Minnesota environmental health researcher Matt Simcik and environmental engineering researcher William Arnold have been developing technology to keep PFAS from moving from landfills into groundwater. MnDRIVE Environment funding is supporting this work which, upon completion, might be used to protect water at compost sites.

MnDRIVE Environment will be continuing conversations this spring around strategies for addressing PFAS contamination in the environment. Between entities like SMSC that are seeking to protect the planet, and MnDRIVE, which stands ready to bring the power of University research to the task, the hope is that society can continue to reap the benefits of composting without exacerbating the PFAS problem, and perhaps proactively solving it.

MnDRIVE researchers Mikael Elias and Lawrence Wackett are studying Acidimicrobium in hopes of harnessing the bacteria’s PFAS-degrading power.

By Caroline Frischmon

Waterproof, nonstick, and flame retardant. Products like raincoats, frying pans, and firefighting foam keep us safe, clean and comfortable. Their durability stems from the presence of carbon-fluorine bonds, which are some of the strongest in organic chemistry. Unexpectedly, these great modern conveniences have also created a widespread environmental problem. Compounds with multiple carbon-fluorine bonds, called PFAS (perfluoroalkyl substances), have accumulated for decades in the environment with no effective way to break down these “forever chemicals.” 

Exposure to PFAS through drinking water is associated with higher cholesterol, certain cancers and suppressed immune responses. Scientists and regulators have tried to address the PFAS contamination through filtering, coagulating, burning and more, but most cost-effective solutions simply concentrate the chemicals and move them away from wells, aquifers and other points of human contact. Now, there’s hope that a bacteria called Acidimicrobium sp. might hold the key to a more permanent solution. Through a MnDRIVE Environment Seed Grant, researchers Mikael Elias and Lawrence Wackett, both University of Minnesota professors in the Department of Biochemistry, Molecular Biology, and Biophysics, will study the bacteria’s promising ability to digest PFAS.

Last year, researchers at Princeton University discovered Acidimicrobium could digest PFAS chemicals and convert them to carbon dioxide and fluoride. It’s the first identified bacteria that actually breaks the carbon-fluorine bond, but scientists are wary of calling it a solution quite yet. The microbes eat too slowly on their own to be effective at the scale needed to address PFAS contamination in the environment. To speed up the process, Elias and Wackett will first need to identify the enzymes that give Acidimicrobium its superpower.

All living things use enzymes, or biological catalysts, to accelerate chemical reactions. They are highly specific to one job, whether it’s digesting fats or sugars or assisting in DNA production. Out of all Acidimicrobium’s enzymes, scientists aren’t sure which ones are responsible for the PFAS reaction. “What we’re really going after now is to identify and characterize the actual enzymes responsible for the degradation process,” states Elias. That understanding will pave the way for improving their efficiency through genetic modification. Eventually, the team hopes to develop the enzymes as a PFAS bioremediation tool.

Wackett and Elias partnered on this project to share their varying expertise. Wackett, an enzymologist, will analyze the bacteria’s DNA sequence to identify which enzymes are likely responsible for PFAS degradation. Elias, a structural biologist, will determine how the structure of Wackett’s enzymes facilitates the reaction. 

Using 3D images to reveal the structure of the enzyme’s active site, Elias examines the arrangement of amino acids, the building blocks of enzymes. “We’re going to look at how the amino acids in the enzyme break down the PFAS molecules,” explains Elias. With that information in hand, he and Wackett will try to engineer better enzymes by manipulating the arrangement of the amino acids.

 In addition to engineering a more efficient Acidimicrobium enzyme, Wackett and Elias will search for other potential PFAS-degraders with related DNA sequences. Bacteria with similar enzymes as Acidimicrobium might digest PFAS even more efficiently, but scientists haven’t been able to test for them yet. “When we have the sequence code, we will know how to look for the enzymes and the genes in other bacteria,” says Wackett, “That’s another big advantage of having the structure and knowing those key amino acids.”

Existing PFAS technologies focus on sequestration rather than degradation. “[Containment] is useful until you have a better solution, but it’s imperfect because it has limited capacity,” Elias points out. “You’re just moving pollutants from one place to another.” The MnDRIVE seed grant provides an opportunity for a better solution. Elias and Wackett hope Acidimicrobium will help them finally eliminate these forever chemicals for good.

This research was supported by MnDRIVE Advancing Industry, Conserving Our Environment at the University of Minnesota.

Caroline Frischmon is a Science Communication Fellow in the Science Communications Lab and is majoring in Bioproducts and Biosystems Engineering. She can be reached at frisc109@umn.edu.

With support from the MnDRIVE Environment Initiative, doctoral candidate Laura Bender harnesses the power of soil fungi to help plants absorb pollutants.

by Kyle Wong

To ensure a healthy crop, Minnesota farmers carefully track soil health, nutrients and the quantity of water flowing through their fields. Since 2015, Minnesota’s Buffer Law also requires farmers to tend to historically overlooked land along the edge of these fields. The law mandates a 50-foot buffer along farm fields bordering public waterways, including irrigation and drainage ditches, to help reduce contamination from farm runoff. Instead of corn, soybean and other cash crops, buffer zones are full of perennial plants and trees adept at absorbing excess nutrients flowing from the fields. With financial assistance through environmental programs like the federal Conservation Reserve Program, farmers have both the mandate and the incentives to establish quality buffers. 

Like their commercial counterparts, plants in buffer zones naturally take up nutrients, but researchers like graduate student Laura Bender, hope to improve the process by focusing on fungi living beneath the soil. Soil fungi colonize the roots of buffer plants to form a symbiotic, or mutually beneficial, relationship. “These relationships help plants take up pollutants that would otherwise escape to the waterways, but soils are often degraded through decades of tillage and fertilizer application and compaction,” Bender notes. “The fungi communities that are naturally present in soil are often degraded or absent.” Supported by a 2018 MnDrive Environment seed grant, Bender works to restore those fungal communities to strengthen buffer plants and keep Minnesota waters clean. 

Bender works with several companies working with fungal amendments and measuring techniques. MycoBloom, for example, developed a fungal amendment containing a type of fungus called  arbuscular mycorrhizal (AM). AM fungi have been shown to help plants absorb nutrients more efficiently. But soil types vary across Minnesota, so Bender has worked with farmer Dave Legvold to test the amendment on the buffer zones on his farm. She collects data from his testing site each year to identify how well the amendment might work in the rest of Minnesota.

Bender collects soil and plant samples from the field site’s buffer zone and measures the level of phosphorus, one of the most common farm nutrients harmful to waterways. Alongside the buffer, she also collects dissolved groundwater. The Research Analytics Lab at the University of Minnesota processes the soil, plant and groundwater samples to calculate the phosphorus levels in each component. Bender uses the data to trace the amount of phosphorus that the buffer plants absorb and the amount that escapes to the water. “We’re measuring how the phosphorus level changes each year to see if the fungi amendment is removing it from runoff water that enters the buffer,” she says.

Phosphorus levels in the buffer are only part of the story; Bender wants to observe the interactions between the AM fungi and the buffer plants. To do so, she needs to look below the soil and analyze the mycorrhizal interactions at a microscopic level. Here, she partners with the company MycoRoots to assess how well the AM fungi colonize the roots of buffer plants. MycoRoots documents the surface area of plant roots covered by AM fungi. Bender uses the data to understand the role that mycorrhizal association plays in phosphorus uptake. Data from 2018 and 2019 revealed that plants with high root coverage from AM fungi tended to take up more phosphorus, leading to lower phosphorus levels in both the soil and groundwater. Bender will conduct more data analysis this fall before forming a conclusion. 

Ultimately, Bender hopes to guide state policy to help farmers understand the best practices for their buffers. To build awareness, Bender plans to lead an online workshop this fall to bring farmers, policymakers and industry partners together for a discussion on buffer-related issues and policies. “It’ll be related to specific topics – different fungi people have used, success or failures in certain settings, opportunities for collaboration, etc. The goal is to identify where others have used amendments and how it has worked for them.” 

With additional funding from MnDRIVE Environment and the University’s Institute on the Environment, Bender hopes to continue research and strengthen her partnerships with the community. Proper guidelines on buffer strips and fungal amendments can help Minnesota landowners establish healthy buffers that benefit them financially and help conserve the environment.

This research was supported by MnDRIVE Advancing Industry, Conserving Our Environment at the University of Minnesota.

Kyle Wong is a writing intern in the University of Minnesota Science Communications Lab, majoring in Microbiology. He can be reached at wong0511@umn.edu

MnDRIVE-funded researcher harvests natural gas from brewery wastewater.

By Nick Minor

From industry pioneers like St. Paul’s Summit Brewery to small-town brewpubs, Minnesota’s craft beer industry has become a point of pride for local beer enthusiasts. But for every pint that flows through the tap, 3 to 10 pints of wastewater–high in carbohydrates, acids, and alcohol–end up in the municipal waste stream to be treated by the city. Breweries pay a premium to remove and treat this wastewater. Still, that same nutrient-rich content provides an ideal food source for hungry microbes capable of turning the waste into energy at the brewery.

With funding from the University of Minnesota MnDRIVE Environment Initiative, researchers led by Professor Paige Novak set out to treat this brewery wastewater while achieving two additional benefits: reducing the load on municipal water treatment systems and producing energy to help fuel brewery operations. 

Kuang Zhu, a recent PhD graduate from Novak’s lab, designed a 2-stage process to treat the brewery wastewater. In the first stage, microbes (called acetogens) feed on the wastewater. Housed in an airtight, oxygen-free compartment, they digest the carbohydrates in the wastewater, producing hydrogen and acetate as byproducts. These byproducts are then siphoned into a second oxygen-free compartment where microbes (called methanogens) consume the acetate, and produce methane, a significant component of natural gas. One of the team’s original innovations was to house the microbes in beads made of a carbohydrate derived from brown algae. This keeps the active microbes in the reactors where they can do their work simply and with little energy expenditure. Hydrogen collected from the first stage, and methane collected from the second can be used to generate power for the brewery while the treated water, significantly cleaner, flows to the local municipal wastewater treatment facility.

Scaling up this research from the lab to the brewery, presented its own set of challenges. Partnering with Fulton Brewing in Minneapolis, the team embarked on “months and months of troubleshooting,” Novak recalls. There were constant tweaks, leaks, and spills; parts to replace, cross-contamination, and even a small wastewater “explosion,” all within a wastewater storage room that averaged a steamy 85 degrees Fahrenheit. 

But this process, slow and tedious though it may be, is a critical part of science. Novak credits the demonstration grant from MnDRIVE, a state-funded initiative that aims to connect basic research with real-world impacts, for making this possible. “It’s such a different kind of trial and error and troubleshooting process,” explains Novak, “and there are so few funding sources for that kind of work. Going through this demonstration project has been invaluable because we figured out all those things we need to pay attention to when we do this again.” 

“Plus,” Novak adds, “it’s been really fun.”

One part of that fun is a public art exhibit that was stimulated by a requirement of MnDRIVE grants to have a public outreach component. After meeting local artist Aaron Dysart at a conference, Novak knew his data-driven approach to art would be a perfect fit for her project and for making the required outreach component much more visible. Dysart plans to create a disco ball suspended outside the Fulton taproom. Not just any disco ball, Dysart’s installation will spin at a rate proportional to the gas produced by the bioreactors. It will project color sequences linked to the ratio of hydrogen and methane. Mounted sideways, Dysart’s disco ball project will be a stream of data bubbling up from the wall of the brewery’s outdoor beer garden.

Of course, getting the bioreactor design into the real world won’t just involve science and engineering. It also requires understanding how the bioreactor fits into the marketplace. Again, thanks to MnDRIVE funding, Novak was able to partner with the Carlson School of Business to conduct some preliminary market research. “They analyzed the technology and the market,” Novak says, “and evaluated different food and beverage industries that would be a good match for our technology.” To Novak’s surprise, Carlson’s research showed that breweries weren’t the only market for the bioreactor. “Breweries don’t typically spend enough money [for this to make a big difference for them].” Instead, potato chip makers and candy manufacturers, both of which generate high concentration wastewaters, could benefit more from the team’s design. Furthermore, the business school team clearly showed that before the technology will be accepted by industries, the design must be plug and play and ready to work out of the box, regardless of the nature of the waste stream.

This goal is now much closer to reality thanks to progress made through the demonstration grant. One day, Novak hopes high concentration industrial wastewater treatment will be as simple as “getting your beads, dumping them in, and watching them go to work no matter what.” MnDRIVE funding not only helped move the technology forward, it also allowed the team to identify industries most likely to benefit from the research and provided an opportunity for consumers to learn about wastewater treatment through a public art installation.            

Nick Minor is an alumnus of the Science Communications Lab, pursuing a master’s degree in zoology and physiology at the University of Wyoming. He can be reached at minor092@umn.edu.

UMN researchers Matt Simcik and William Arnold trap harmful chemicals before they can pass through the environment to our drinking water

by Caroline Frischmon

When you turn on the faucet, you probably trust the water in your glass will be safe to drink. For Minnesotans living in the eastern Twin Cities, this trust evaporated when toxic PFAS chemicals (or per and poly-fluoroalkyl substances) infiltrated their groundwater. PFAS are found in many products, ranging from nonstick cookware and food packaging to waterproof clothing. Despite their ubiquity, scientists suspect high concentrations of the chemicals lead to cancer, obesity, and other health problems. 3M formerly manufactured PFAS at its Cottage Grove facility, which caused the east metro contamination. Now the chemicals are threatening drinking water for Minnesotans across the state.

“This is an issue everywhere,” says Matt Simcik, a University of Minnesota Environmental Health Science professor who has studied PFAS for nearly 20 years. He explains that contamination is widespread because landfills throughout the state can also leak the chemicals.

When we throw away PFAS-coated products like raincoats and upholstery, the compounds leach into the water that passes through the landfill. Operators either pump this water (called landfill leachate) to a settling pond or truck it to a wastewater treatment facility. Neither option effectively filters PFAS before discharging the contaminated leachate into the environment. Plants absorb some of the released PFAS, but the rest can percolate into groundwater. With the help of a MnDRIVE Environment seed grant, Simcik and his colleague William Arnold in the Department of Civil Engineering, are developing a solution to prevent the release of landfill PFAS.

Known as forever chemicals, PFAS can persist indefinitely in the environment. We don’t have an effective way to break them down, so Simcik plans to trap the compounds instead. He and Arnold previously developed a groundwater treatment technology that uses a coagulant or clumping agent. These big molecules bind to PFAS to make the chemicals stick together and become entangled in the soil — where they can’t travel to our faucets. While it has shown great promise in the laboratory, they are now field testing this method. Depositing the coagulant within a landfill could immobilize the chemicals in layers of waste even as the leachate flows through the site. Simcik’s plan would effectively turn landfills into PFAS storage containers, and prevent contamination from spreading further in the environment.

While this sounds promising, applying the groundwater technique to landfills is more complicated than simply identifying the best location to bury the coagulant. Groundwater is relatively clean, but landfill leachate can pick up contaminants other than PFAS as it passes through layers of waste, which reduces the coagulant’s effectiveness. Before testing the treatment method in a landfill, the MnDRIVE project will investigate how to maintain performance even as the leachate composition varies.

Simcik must also confirm that the treatment is long-lasting. If the chemicals can leak out of their trap, the coagulation method would just delay the problem rather than solve it. The lab will monitor the longevity of the coagulants, but Simcik anticipates the solution will be long term.
Forever chemicals require a lasting solution because they can endure many years in the environment. 3M phased out production of the two most prevalent types of PFAS (called PFOS and PFOA) in the early 2000s after they were detected in animal bloodstreams worldwide. Over a decade later, the chemicals still linger in the environment near the 3M facility. After 3M phased out PFOS and PFOA, other manufacturers introduced new PFAS chemicals as replacements without proof they were any less toxic.

Ongoing research on the substitute PFAS compounds now points to similar health hazards as the originals, so companies may someday end up replacing these “replacement” chemicals. As this toxic cycle repeats itself, Simcik hopes to at least keep PFAS, both old and new, locked away in landfills and out of our bloodstreams. “Hopefully, we can prevent future contamination. That’s our goal,” he says.

Caroline Frischmon is a writing intern in the Science Communications Lab, majoring in Bioproducts and Biosystems Engineering. She can be reached at frisc109@umn.edu