Astronauts Living in Space Can Eat Bacteria That Feed on Human Waste

Starting a new colony on another planet doesn't seem like the worst idea at the moment. But getting things started is probably going to be tough—good luck squeezing a Whole Foods onto a space shuttle. A new study reports that bacteria combined with human waste from future space travelers could be the solution.

Researchers at Penn State report that three types of bacteria will process waste, grow in conditions that are too extreme for the kinds of nasty species that can make us sick and are potentially edible. In other words, Mark Watney, also known as The Martian, was right—poop definitely has its uses. But unlike Watney's poop-related farming, there's no potato or other vegetable separating you and your waste—these bacteria "eat" the poop and then the astronauts eat the bacteria.

It's not like people haven't thought of this before. Bacteria to break down matter "is something we use frequently on Earth for treating waste," researcher Christopher House noted in a press release announcing the publication of his team's work in Life Sciences in Space Research. "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."

The researchers tested three species of bacteria in a reactor built with aquarium parts that wound up with about the same volume as a basketball. Two species grew well in temperatures and pH levels that were high enough to kill off pathogens; another species grew in the kind of methane-rich environment created when bacteria munch on poop. Best of all, the bacteria could consume about half of the solid waste in less than a day. "That's why this might have potential for future space flight. It's faster than growing tomatoes or potatoes," House said.

House and his team aren't the only ones working on the problem of supporting life in space for the long haul. The European Space Agency's MELiSSA project goes beyond just food; it's attempting to create an all-in-one life support system that could also serve as a source of oxygen and water.

The bacteria in this paper aren't perfect for our nutritional needs. According to the study, the makeup of the bacterial biomass ranges from between 15 to 61 percent protein and between 7 to 36 percent lipids. Earthlings are generally recommended to get about 20 to 35 percent of their diet from fat and between 10 to 35 percent from proteins, according to the National Academies of Sciences, Engineering and Medicine. No single bacterial species produced a biomass with spot-on ratios.

And, of course, there's the question of taste. Researchers did not disclose the existence of, nor the results of, any taste tests—which Newsweek assumes is for the best.