Mission space food: Sugar-growing bacteria go into orbit

Matt Damon’s character in The Martian has to grow potatoes in his own faeces to survive on Mars. But there may be more appealing ways to make food in space, like using bacteria to make chemicals we can eat, such as sugar.

The idea is now set to be put to the test in space for the first time. Genetically modified bacteria will be sent up on a German satellite in 2017 to see if they can survive the launch and cosmic radiation, and function under reduced gravity.

The satellite will spin for six months at a speed that simulates Martian gravity, which is one-third that on Earth. It will also test the same bacteria under lunar and zero gravity, to see if they could function on the moon or a space station.

The sugar could be turned into not only food, but also fuel. And bacteria could also be engineered to make drugs and building materials, slashing a spacecraft’s payload. Launching things against Earth gravity is extremely expensive. This is the obvious way to break through the problem of ‘upmass’.

The linchpin is a type of plankton called Anabaena, which uses photosynthesis to make sugars from carbon dioxide, water and sunlight. Lynn Rothschild’s team has tweaked the microbe’s genes so that it excretes some of the sugars to provide a food source for other modified bacteria, a system they have dubbed PowerCell.

The team has engineered a microbe called Bacillus subtilis to turn those sugars into a red pigment. Some B. subtilis will fly with PowerCell, and any colour change will be detected by an on-board sensor. That will show whether the bacteria are behaving as intended, as the satellite will not return to Earth, but burn up in the atmosphere after a year.