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Solving the P Paradox

A group of researchers is working on a potentially game-changing approach to capturing and repurposing phosphate, a critical nutrient and notorious pollutant.

Bo Hu, Vanessa Pegos, Mikael Elias

Left to right: Drs. Bo Hu, Vanessa Pegos and Mikael Elias

First in a four-part series on the first round of research projects funded through the College of Biological Science' Grand Challenges in Biology Postdoctoral Program.

Phosphate is a cornerstone of food production. Modern agricultural methods rely on its prowess as a fertilizer. However, it’s also a major source of water pollution from runoff into lakes, rivers, and notably the Gulf of Mexico with its expansive “dead zone,” an area starved of oxygen due to massive phosphate-fed algal blooms. Closer to home, it can cause lakes to turn green through eutrophication. Yet phosphate, the mineral form of phosphorus, is also relatively rare and becoming rarer as known supplies dwindle, giving some urgency to efforts to increase efficiency and recycle rather than simply remediate.

“We cannot just talk about phosphorus removal anymore,” says Mikael Elias, part of a three-person team working on a new approach to this threat to the environment and, potentially, global food security. Elias notes that some experts estimate that known supplies of phosphate could run out in as few as five decades. But unlike fossil fuels, there’s no readily available alternative to maintain food production at today’s levels. “We need to think about how to capture and reuse it.”

Elias, along with Bo Hu and Vanessa Pegos, one of four post-doctoral associates selected as part of the first cohort of the college's Grand Challenges in Biology Postdoctoral Program, are combining their expertise in structural biology, protein engineering, bioremediation and molecular biology to develop an entirely new approach.

“Current approaches aren’t efficient enough to remove trace amounts of phosphate from water,” says Hu whose expertise in bioreactors and phosphate bioremediation is key to turning the group’s findings into real-world applications. “By genetically modifying specific species we will be able to increase efficiency.”

Specifically, the researchers are engineering the phosphate uptake process in select bacteria to put the microorganisms to work cleaning up trace phosphorus in wastewater left behind by commonly used chemical and biological approaches, and turn it into a reusable form.

“A lot of people are trying to find existing bacteria that can do a better job at phosphate recovery,” says Elias. “Our approach is different. We are studying how these microorganisms capture phosphate and trying to engineer the system to make it better.”

Elias points out that because organisms evolve in a specific environment, bacteria that are good at gobbling up phosphorus in one type of milieu may not do so with the same efficiency in a different context.

“The whole idea in engineering bacteria is to ensure that they work optimally to meet specific needs in a particular environment,” says Elias.

Vanessa PegosPegos, who brings considerable experience working with phosphate uptake systems to the mix, serves as a bridge between the Elias and Hu labs. All agree that the collaboration is natural given the complementary nature of their research interests. But one of the benefits of the program is the chance for a molecular biologist like Pegos to get her hands dirty (literally!) in the field.

“This program creates a unique opportunity to step out of the lab and learn about the engineering aspects of bioremediation,” says Hu. “Vanessa will get to know much more about how the research is applied in the field. She’ll also get to work with manure and waste water and large bioreactors!”

But bridging labs and, especially, labs that bring together the basic and applied research that are needed to address an issue like phosphate remediation and reuse, has a more practical purpose, too. “We can do better and we must do better to address these large environmental problems,” says Elias. “Addressing a problem on the scale we are talking about would be very difficult with just one lab no matter how broad the research focus. The Grand Challenges program facilitates the kind of collaboration needed to make a real impact.” — Stephanie Xenos

“We cannot just talk about phosphorus removal anymore. We need to think about how to capture and reuse it.” – Mikael Elias

Elias is an assistant professor in the Department of Biochemistry, Molecular Biology and Biophysics and the BioTechnology Institute associated with the University's MnDRIVE initiative. Hu is an associate professor in the Department of Bioproducts and Biosystems Engineering.


June, 2016