Currently, our dreams of starting a colony on another planet are not very realistic. In addition to the dangers that a manned space flight of a distance to a planet like Mars would bring to astronauts in terms of their health, actually surviving once on the new planet is not currently feasible. With our inability to resupply a colony on another planet due to the extreme time it would take for a new spacecraft to make the trip, it’s important that any established space colony be able to support its residents entirely.
Researchers at Penn State may have arrived at a novel new solution after finding edible bacteria that process human waste. By using human waste to grow a huge amount of these edible bacteria, astronauts may be able to feed themselves while on other planets.
Bacteria breaking down waste is not at all a new concept. Christopher House, a researcher on the study, announced in a press release that using Bacteria to break down matter “is something we use frequently on Earth for treating waste…What was novel about our work was taking the nutrients out of that stream and intentionally putting them into a microbial reactor to grow food.”
In that sense, astronauts wouldn’t be eating edible bacteria itself per se, but rather the nutrients collected from these three types of bacteria that can both process waste and grow in extreme environments. These same extreme environments are too hazardous for the dangerous bacteria that actually pose a threat to humans, so eating these edible bacteria is actually quite safe.
In order to come to this conclusion, the researchers took three different species of bacteria and put them in a reactor that they built with aquarium parts. As a simple construction that’s roughly the size of a basketball, it’s definitely possible that it could be included on a trip to another planet. Two of the species studied grew well in the same temperatures and pH levels that would kill off pathogens, while another thrived in the methane-rich environment created when bacteria process waste. Perhaps most notable about the discovery is that the bacteria had the potential to consume around half of the solid waste in less than a single day.
House expounded upon the significance of the speed of these bacteria, explaining “that’s why this might have potential for future space flight. It’s faster than growing tomatoes or potatoes.”
It’s important to note that House and his colleagues aren’t the only ones working on supporting life in space. Newsweek reports that The European Space Agency’s MELiSSA project has a reach that extends beyond food, attempting to create an all-in-one life support system that could support a human entirely as a source of oxygen and water as well.
The study notes that the solution of these edible bacteria is not perfect, and that the food isn’t optimized for our nutritional needs. The conclusions found that the makeup of the bacterial biomass was between 15 to 61 percent protein and between 7 to 36 percent lipids. Current nutritional guidelines recommend that we get around 20 to 35 percent of our diet from fat and between 10 to 35 percent from protein.
While the edible bacteria might not be the best way to support life long-term due to the lack of nutritional balance, it’s another step forward in our work to discover a way to sustain a space colony. Further research is needed in order to determine whether this sort of discovery could be refined and ramped up in a way that could bring about meaningful change.