A University of Georgia professor is growing edible protein from carbon dioxide using microbes, requiring far fewer resources and causing less environmental impact than conventional vegetable and animal protein.
Joseph Usack, an assistant professor in the Department of Food Science and Technology at UGA’s College of Agricultural and Environmental Sciences, focuses on developing sustainable food systems to help combat climate change and mitigate food insecurity. Growing microbial-based protein is not a new feat for him.
“Growing microbial-based protein via carbon dioxide capture is one of several emergent biological technologies that will help facilitate a future sustainable bioeconomy, which the world urgently needs,” Usack said.
This process of growing protein is a two-stage microbial process involving the capture of carbon dioxide from variable sources and converting it into edible protein. This feat requires energy in the form of hydrogen gas, a process Usack said is “relatively simple.”
“We use electricity, preferably renewable electricity, to electrolyze water into hydrogen and oxygen. We then feed the hydrogen and CO2 to an ancient group of microbes known as acetogens, which convert these gases into acetic acid, the same compound in vinegar,” he said. “With this vinegar, we can feed a whole host of different microbes. Here, we grow yeast cells, whose proteins, fats and vitamins are extracted and converted into various food products.”
The appeal of microbial protein is its minimal use of fossil energy and other resources. In a review article titled “Microbes: Food for the Future” from the journal Foods, researcher Matilde Ciani and co-authors acknowledge the benefit of capturing CO2 emitted from sources such as “flue gas from power stations, incinerators and cement factories; emissions from food processing, anaerobic digestion of plants” and non-emission sources, including the air we breathe.
Renewable sources of energy like wind turbines and solar panels can also be used to generate the electricity needed to split water molecules into hydrogen and oxygen. “In Europe, using renewable electricity is an obvious choice because there is so much of it. The power grid often cannot store all the produced electricity, which is problematic. Using renewable electricity to generate microbial protein is a way of dealing with the grid storage issue,” Usack explained.
Microbial protein technology uses nutrients, such as nitrogen, much more efficiently than vegetable and animal protein produced through conventional farming methods.
Ciani and her co-investigators state in their article: “Conventional agriculture-based protein production converts only a fraction of the supplied nitrogen into plant and animal protein; the remaining nitrogen is lost to the environment causing contamination of aquifers, eutrophication of surface waters, ocean acidification and GHG emissions. In bioreactor-based MP (microbial protein) production, almost all of the supplied nitrogen (and other nutrients) ends up as consumable protein with minimal environmental impacts.”
As well as being environmentally beneficial, microbial protein technology is a more versatile and secure way to produce certain foods.
“You can generate large quantities of microbial biomass in a controlled, self-contained system independent of weather, season and climate,” said Usack. “You also don’t have to worry about pests, insects, blights or zoonotic diseases, as you do with vegetable and animal products. There are many advantages.”
The technology is also unbounded geographically and easy to scale. Ciani’s review reports that in the next 30 years, “urban areas will host more than two-thirds of the world population.”
Microbial protein does not require arable fields or pastures, so the technology can be deployed wherever demand for protein exists, which would help secure the food sector.
Learn more about research being done in food science and technology at UGA on the department’s website.
