Tiny Organisms, Big Benefits

Wastewater microalgae could be a nutritious, renewable source of animal food

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By Julie Kendrick

algaeIn an era when a new "superfood" status seems to be declared every few minutes (we're looking at you, kale), it seems only fair that animals have a chance to enjoy some of the latest trends in healthy eating too. After years of popularity as a delicacy in Asian cuisine and as a supplement for the health-conscious, microalgae like spirulina and chlorella are now being explored as a potentially nutrient-dense ingredient for animal feed.

One promising project, which includes CFANS researchers, aims to select the most promising algal strains with properties of high growth rates and desired nutritional composition, find ways to cultivate them on food and agricultural waste water streams, and then use them as a high-energy, nutrient-dense feed ingredient for poultry, swine, fish and cattle. "There is tremendous interest in the feed and food animal industries to develop and utilize novel feed ingredients that have high nutritional value, provide nutraceutical properties to diets, can be produced with existing resources without increasing the amount of arable land to produce feed resources, and is good for the environment," says Jerry Shurson ('81–B.S., animal science), professor in the Department of Animal Science. "The technology we are developing meets all of these criteria and will help "close the loop" on nutrient re-cycling in our food production systems."

The university's pilot testing facility for algae processing at the Metropolitan Wastewater Treatment Plant in St. Paul.

The project is being developed as part of the MnDRIVE partnership between the university and the state of Minnesota, which aligns areas of university strength with the state's key and emerging industries to advance new discoveries that address grand challenges in the areas of robotics, sensors and advanced manufacturing; global food ventures; advancing industry, conserving our environment; and discoveries and treatments for brain conditions.

From low-value waste to highly nutritious feed ingredient

"There is a tremendous amount of inedible carbon, nitrogen, phosphorus, and other nutrients in waste water produced by food processing and agriculture industries which are wasted and require costly treatment to reduce environmental concerns," Shurson says. His team is targeting recycling nutrients in food and agricultural waste water streams from dairy, meat and vegetable processing facilities as well as animal manure and co-product streams from ethanol production through microalgae production. The microalgae have the ability to convert nutrients in those low-value waste steams into a nutrient-dense, highly digestible, palatable and safe feed ingredient for animals. "The process we are developing is very attractive to our industry partners and would potentially help them more effectively manage the costly problem of managing waste water streams by turning them into revenue-generating streams by producing and marketing a valuable new feed ingredient for food-producing animals too," Shurson says.

The Norway-Minnesota connection

Shurson is a strong believer in the power of collaboration and has worked with researchers at the Norwegian University of Life Sciences in Ås, Norway, on evaluating the benefits and limitations of novel feed ingredients for food-producing animals, including fish. The University of Minnesota has enjoyed a strong research partnership with the Norwegian university for many years.

Shurson is leading another interdisciplinary research team at the U of M to further expand knowledge in this field. The University of Minnesota is an academic partner in the Foods of Norway consortium, which is a multi-million dollar, eight-year, multidisciplinary international research project focused on developing sustainable feed ingredients from natural bioresources not suitable for direct human consumption. Shurson's team is working closely with Margareth Overland, a professor at the Norwegian University of Life Sciences, on studies involving the feeding applications of novel feed ingredients, including microalgae, in animal feeds. Overland also has strong ties with CFANS, where she was a former Animal Science graduate student.

Potential as a "significant feed source for the future"

Shurson's collaborators on the project include Paul Chen from the Department of Bioproducts and Biosystems Engineering; Chi Chen, departments of Food Science and Nutrition/Animal Science and Pedro Urriola ('06–M.S., animal science) from the Department of Animal Science. Another collaborator is Roger Ruan, professor in the Department of Bioproducts and Biosystems Engineering. His focus has been to produce algae and investigate optimal harvesting procedures and techniques. "We provide the algae to doctors Shurson, Urriola, and Chi Chen and they analyze its nutritional components for animal feed," he says.

Along with other members of this team, Ruan thinks the project has excellent potential. "Microalgae are very healthy and nutritious microorganisms due to their high protein content of up to 60 percent and often high concentrations of omega-3 fatty acids," he says. "This makes it an attractive and significant feed source for the future."

The team includes Roger Ruan, Pedro Urriola, Paul Chen, Chi Chen, Gerald Shurson and graduate student Yiwei Ma.

Ruan has appreciated the amount of interdisciplinary work supported by the project, both with university colleagues and industry representatives. "We have meetings with companies to hear about the immediate problems they're facing. Before MnDRIVE, we never knew what their needs were, but now we can focus our efforts and, we hope, make a difference to the community."
The next steps for the project are to find the best combinations of waste water streams to match with the best strains of algae, to optimize their nutrient profiles, growth rates, and economic potential for mass production. The team is also doing chemical analysis and metabolomics evaluations on selected microalgae strains to identify potential anti-nutritional factors as well as nutraceutical properties. The long-term goal is to develop and conduct larger scale pilots to evaluate the techno-economic feasibility of this technology for commercial application, and ultimately contribute to the regulatory process to receive government approval for microalgae use in animal feeds. "Our goal is to work through the many challenges of bringing this exciting concept to a commercialization reality," Shurson says.

The cool stuff

Will business have an interest in the type of product this project might eventually produce? According to Steve Markham, a senior merchant with the agricultural cooperative CHS, "We have a number of agriculture processing businesses, including ethanol plants, so we're very interested in the idea of growing protein on a waste stream." Markham says his company's support of MnDRIVE makes sense. "We're an agriculture company, and we're owned by farmers, so if we support anything, it should be with universities involved in agricultural research."

Still, it's hard to predict whether this great idea will become a commercialized reality. "Sometimes things will work in a lab, but in the business world there has to be a cash flow," Markham says. "But the world changes rapidly, and so do technology and commercial rules. The value of protein might change, or they might get hyperefficient at producing the microalgae." In Markham's mind, one thing is clear: "Usually all the really cool stuff comes from the university."