As the global population continues to grow, the strain on our environment intensifies. Agriculture occupies vast land areas, releasing nutrients into the environment, while industrial production generates significant waste and consumes enormous amounts of energy, contributing to climate change.
In a groundbreaking development, researchers from DTU (Technical University of Denmark) have discovered a way to address these challenges by turning industrial waste into a valuable resource for food production. Using the salt-tolerant yeast Debaryomyces hansenii (D. hansenii), the team has demonstrated the potential to produce proteins at a low cost and with minimal energy consumption, paving the way for a more sustainable future in food production.
Associate Professor José Martinez from DTU Bioengineering has spent years researching yeast cells that thrive in extreme conditions, such as high salinity. D. hansenii, which naturally thrives in environments with salinity levels up to six times that of seawater, provided a unique opportunity for Martinez and his team.
“There are industries that generate nutrient-rich waste streams with high salt content, which poses a disposal problem and incurs high costs,” explained Martinez. “We thought, why not grow D. hansenii in these salty waste streams to make use of the nutrients?”
Martinez’s team collaborated with Arla Foods to test the yeast in a highly salty residue from cheese production, rich in lactose. The results were promising, but the yeast growth was limited by a lack of nitrogen. A fortuitous conversation with Manuel Quirós, a specialist at Novo Nordisk, revealed that Novo Nordisk had a nitrogen-rich, salty residue from hemophiliac drug production. The two companies’ waste streams were combined, creating an ideal growth medium for D. hansenii.
“We mixed the two waste streams as they were, without needing to add fresh water or sterilize the fermentation tank because the salt content prevented contamination. It was a plug-and-play solution,” said Martinez.
To enhance the yeast’s utility, Martinez’s team employed CRISPR technology to modify D. hansenii to produce a fluorescent protein, demonstrating the yeast’s potential for producing a variety of valuable products. This method not only simplifies production but also opens doors to a range of applications, including milk substitutes, artificial meat, and protein-based pigments.
Martinez sees potential for D. hansenii beyond food. The yeast biomass could be used in animal feed, or even in processing meat for more efficient maturation. Additionally, Martinez is involved in research to develop sustainable fuels, aiming to modify the yeast to produce lipids that can be converted into green fuel.
While the research has shown great promise, moving from laboratory-scale experiments to full-scale commercial production presents significant challenges. Scaling up from the current 1-5 liter experiments to the thousands of liters required for commercial production will require overcoming obstacles related to oxygen supply and other unforeseen issues. Martinez predicts it may take at least a decade before D. hansenii is used in commercial production.
This research is a significant step toward a more sustainable future, turning industrial waste into a resource for food and fuel production. As industries like Novo Nordisk strive to reduce waste and carbon emissions, innovative solutions like those developed by Martinez’s team are crucial. The work with D. hansenii offers a glimpse into how we might sustainably feed a growing population while minimizing environmental impact.
By Impact Lab
