When Brenda Cansino-Loeza joined the University of Wisconsin-Madison as a postdoctoral researcher three years ago, she had plenty of experience working on earth-bound projects; in fact, her research focused on developing tools to make the water-energy-food nexus more sustainable. So, she was a bit surprised when Victor Zavala Tejeda, the Baldovin-Dapra Professor of chemical and biological engineering, offered her the chance to work on a DARPA-funded collaboration focused on outer space.
Cansino-Loeza, who earned her PhD at the Universidad Michoacana de San Nicolás de Hidalgo in Morelia, Mexico, was always up for a challenge. So she gladly took on the project, which involved studying how to design biomanufacturing systems in orbit.
Now, she has published a paper and delivered a NASA technical report discussing how choosing the right bacteria and the right preservation method could be the key to long-term survival in space. In this Q&A, she talks about what sparked her interest in microbial manufacturing in space and how her work helps evaluate systems that could support future long-duration space missions.
Why grow microbes in space?
This project was a collaboration with the University of Texas at Austin. Their team was working on the biological side, developing radiation-resistant microorganisms that could survive in zero gravity and produce lactic acid, a platform chemical used to make polylactic acid, a biodegradable polymer that can be used for 3D printing. If you can produce polylactic acid in space, you could use it for 3D printing tools, replacement parts, or even building materials on demand.
We said, OK, let’s think of this as a living factory in space that produces a platform chemical that can be used to manufacture a wide variety of products.
What was your role in the project?
In space, there are a lot of resource constraints, and it is very expensive to send everything up from Earth; by some estimates, it costs $10,000 per kilo. One way to produce value- added products in space could be through these biomanufacturing systems.
I conducted a technoeconomic analysis to compare which is better: sending materials directly from Earth to space, or sending the resources needed to deploy a system that could produce those materials in space.
We mapped all the design components, such as feedstocks, power, cooling and equipment into a common basis in terms of mass. By doing this, we could estimate how much material would need to be transported from Earth, estimate the launch costs, and compare different systems designs. For example, we evaluated the system with different microorganisms and preservation methods to determine which options could produce the most lactic acid with the lowest system mass. These comparisons helped us identify which biological system and preservation method could work best for producing materials in space.
So, what is the best way to grow microbes in space?
One important finding from our research is that preservation strategies that work well on Earth may not be optimal in space. On Earth, microbes are typically preserved in liquid cultures for fermentation.
But in space, factors such as radiation and microgravity can increase the challenges of maintaining liquid cultures. We evaluated lyophilization—or freeze-drying—as an alternative preservation method. This process removes water from the microbes, allowing them to be stored in a dry and stable form at room temperature. When they are needed, the microbes can be rehydrated with water and activated for fermentation.
We found we can save a lot of mass by using freeze-dried microbes, since the liquid culture require continuous cooling, which adds energy demands. We also found that a strain of E. coli engineered to produces lactic acid has the best performance.
Is lactic acid the only thing you can biomanufacture in space?
No, many different products could be produced through biomanufacturing in space. The broader goal is to connect different biomanufacturing systems so that the outputs or waste streams from one process can serve as inputs for another, creating more circular systems and reducing the need to send supplies from Earth.
Could these microbes produce habitats on the moon?
Producing materials for lunar habitats is possible, but it would take time. Biomanufacturing systems produce materials gradually, so they could help generate materials locally during future space missions.
Are there more space projects in your future?
I never thought I would be working on a project related to space, but it was a great opportunity. We even traveled to Cape Canaveral to meet with the team in person, discuss results, and visit some of NASA’s facilities. This project, for me, was a first step into this field, and it showed me that there are many opportunities for research in this area!
Featured image: By analyzing the mass, cost and productivity of lactic acid biomanufacturing systems, Brenda Cansino-Loeza is helping determine which systems could best support long-term space missions. Credit: Joel Hallberg