Fighting Farmland Pollution with Fungi

Fighting Farmland Pollution with Fungi

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

Postdoctoral Research Associate

Postdoctoral Research Associate in Microbiology, Pharmacology, and Gastroenterology

A postdoctoral position is immediately available in the BioTechnology Institute and Department of Medicine, Div. of Gastroenterology, at the University of Minnesota.

Mike Sadowsky and Alex Khoruts are looking for a highly motivated postdoc to work on a project related to the development of new and novel formulations of microbiota-based for a variety of human diseases. This project follows up on our encapsulation technology for intestinal microbiota transplantation in adult patients. However, an important goal is development microencapsulation to enable oral administration of live microbiota to patients who may have difficulty with capsules, e.g., young children. This postdoctoral project will help develop the technology and follow engraftment of intestinal microbiota in animal models and patients using DNA sequencing, qPCR, metagenomics and culturing methods.

All applicants must have a Ph.D. in microbiology, pharmacology,  or a relevant field. Expertise in microbiology, microbial ecology, pharmacology, and analytical chemistry, is highly desired.

The position is for 2 years, and is annually renewable depending on performance and availability of funding The successful candidate will receive training in professional and personal development, research collaboration, presentation and publication of results, outreach, and mentoring. The position includes a competitive salary and health insurance. Review of applications will begin immediately and will continue until the position is filled. A near-term start date is desired.

Applications should include: (i) brief cover letter, (ii) curriculum vitae, (iii) a brief description of past research accomplishments and future research goals (under two pages), and (v) the names and contact information for three references. All materials should be submitted as a single combined PDF to Alex Khoruts (khour001@umn.edu) and Mike Sadowsky (sadowsky@umn.edu) with “Postdoc Application” in the subject line. Any questions should also be directed to these email addresses.

Ann Yetter

Ann Yetter

Ann Yetter

Facilities and Events Coordinator

ayetter@umn.edu

Facilities questions for PMB, BTI, and EEB, UCard and key requests, building emergencies, autoclave issues, space use updates, coordinating special events

Ann lives in St Paul with her husband and Boston Terrier. She enjoys connecting grad students and PIs to the solutions they need to function in their research, and she relishes the arcane details of the work going on in CBS. In her off-hours, Ann bikes the twin cities, bakes, and gardens.

The Plant Microbe Match

The Plant Microbe Match

University of Minnesota researchers pair plants with microbes to remove arsenic from contaminated soils

by MaiLei Meyers

The contamination of soil with heavy metals like arsenic is a lasting legacy of the industrial age. In fact, the World Health Organization has identified arsenic as one of 10 chemicals of major concern. Minnesota, like other industrial states, had its fair share of arsenic-contaminated land, including the South Minneapolis Contamination Superfund and Perham Arsenic Superfund sites. Cleanup efforts traditionally involve the removal of contaminated soil and its long-term storage in a designated landfill. University of Minnesota scientists Michael Sadowsky and Cara Santelli are working on a sustainable alternative using hyperaccumulator plants that remove toxic metals from soil and incorporate them into plant tissue.  

“You can harvest and burn plants to collect the metal from their contents. In environmental clean-up, it’s called phytoremediation,” explains Michael Sadowsky, Director of the University of Minnesota’s BioTechnology Institute and an expert on plant-microbe interactions. Santelli, his partner on the project, is a geomicrobiologist in the Department of Earth Sciences. Together, they plan to augment the natural uptake of toxic metal using a class of soil microbe called rhizobacteria, which form symbiotic relationships with plants.

The research began in the greenhouse with a study of two plants capable of accumulating metals at a different rate. Using soil from EPA Superfund sites, the labs will measure the amount of metal absorbed by the plants when paired with microbes capable of immobilizing toxic metals in the soil or making them more accessible for natural uptake.

With that knowledge in hand, Santelli and Sadowsky will move on to local contaminated sites and test their findings in the field.

The Minnesota Pollution Control Agency and the Department of Agriculture granted access to Superfund sites during the pilot project funded with a seed grant from the MnDRIVE Environment initiative. The UMN team has partnered with Geosyntec, a national consulting firm with expertise in environmental engineering and the cleanup of contaminated metals. Geosyntec will assist in scaling successful field trials.

 Seed Grant Funding

Projects like Sadowsky’s current phytoremediation research could help increase visibility for seed funding programs like MnDrive.  “Without seed funding, the ability to generate foundational data for federal funding is limited,” says Sadowsky, who also serves as Co-Director of MnDRIVE’s bioremediation initiative.

In addition to seed funding, MnDRIVE promotes collaboration with local industry and government agencies. “We’re providing research that can help drive Minnesota’s economy and protect its environmental legacy. Since its inception five years ago, MnDRIVE has played a crucial role in developing new technologies and promoting collaboration between research institutions, industry, and government.”

MaiLei Meyers is a double major in Film and Journalism with an emphasis in Strategic Communications and Public Relations at the University of Minnesota’s College of Liberal Arts and an intern in the BioTechnology Institute’s Science Communications Training Program.

Engineering a self-cleaning environment

Engineering a self-cleaning environment

UMN researchers create self-cleaning Biohubs to mitigate the impact of pollutants in Minnesota’s waterways

by Lauren Holly

Minnesota’s Iron Range is dotted with active and abandoned mining sites. Left untreated, runoff from these sites can flow into the environment and release heavy metals and organic pollutants, ultimately endangering wildlife and threatening human health.

But what if we could engineer the environment to clean itself? With support from the MnDRIVE Environment initiative, researchers in the BioTechnology Institute’s Schmidt-Dannert lab are developing Biohubs using genetically engineered proteins capable of breaking down heavy metals and removing toxins from mine drainage and other industrial sites.

Biohubs take advantage of a protein’s natural tendency to self-assemble into stable shell-like structures. Their porous surface converts harmful metals and organic pollutants into non-toxic components.

Based on similar structures found in nature, the lab’s model Biohub converts toxic mercury compounds into a form that can be released safely in the environment. The process relies on modified proteins that bind toxins while enzymes, small proteins capable of catalyzing biochemical reactions, convert mercury to its inert elemental form. The system is “self-cleaning” because the enzymes remain active inside the Biohub until it encounters the next metal, and restarts the process.

On-site, the Biohubs are placed in glass or metal columns that act as a filtration system; contaminated water enters through one end of the column and exits at the opposite end of the column free of toxins.

Using enzymes to clean the environment has advantages. They are versatile and leave no toxic residue, but enzymes found in nature are not always stable, and Schmidt-Dannert’s team needed a way to protect and stabilize the proteins. Enter Minnepura Technologies; a biotech startup co-founded by University of Minnesota Professors Alptekin Aksan and Lawrence Wackett. Minnepura specializes in the development of biocomposite materials designed to encapsulate and protect proteins. Minnepura and will encase the Biohubs in an easily adaptable, light-weight silica that supports the structure over time.

“Initial studies will focus on remediation of heavy metals from mine drainage, but the system could also be applied to clean up of pesticide-contaminated soil or water near agricultural land,” explained Maureen Quin, a lead researcher on the project.

Schmidt-Dannert believes engineered proteins hold considerable potential as a platform technology for sustainable bioremediation. “If we can get this to work with organic compounds, this solution could be very versatile and able to convert a variety of different pollutants.” In states like Minnesota trying to balance the competing demands of industry and environmental stewardship, Biohubs may help the environment clean itself.


Lauren Holly is an intern in the BioTechnology Institute’s Science Communications Training Program.