‘Living paint’ could produce oxygen for space colonies, Surrey creators say

A ‘green living paint’ that includes photosynthesising bacteria could provide oxygen for human colonies on Mars, its developers have claimed.

The new ‘biocoating’, a type of water-based paint that encases live bacteria, was created by a team at the University of Surrey.

The paint – which researchers said could also play a part in sustainability measures on Earth – features Chroococcidiopsis cubana, a bacteria that produces oxygen while capturing carbon dioxide. The species, which is classified as an ‘extremophile’ because it can survive challenging conditions, is usually found in the desert and requires little water for survival. 

“With the increase in greenhouse gases, particularly CO₂, in the atmosphere and concerns about water shortages due to rising global temperatures, we need innovative, environmentally-friendly, and sustainable materials,” said Dr Suzie Hingley-Wilson, senior lecturer in bacteriology at Surrey.

“Mechanically robust, ready-to-use biocoatings, or 'living paints,' could help meet these challenges by reducing water consumption in typically water-intensive bioreactor-based processes.”

To investigate the suitability of Chroococcidiopsis cubana, researchers immobilised the bacteria in a mechanically robust biocoating made from polymer particles and clay nanotubes in water, which was fully dried before rehydrating. They observed that the bacteria within the biocoating captured CO₂ and produced up to 0.4g of oxygen per gram of biomass per day. Continuous measurements of oxygen showed no signs of decreasing activity over a month. 

Similar experiments with Synechocystis sp., another cyanobacteria usually found in freshwater, found it was unable to produce oxygen within the biocoating.

Simone Krings, lead author of a paper on the study and former postgraduate researcher in the Department of Microbial Sciences at Surrey, said: “The photosynthetic Chroococcidiopsis have an extraordinary ability to survive in extreme environments like droughts, and after high levels of UV radiation exposure. This makes them potential candidates for Mars colonisation.” 

The work was funded by a research grant from the Leverhulme Trust. It was published in Microbiology Spectrum.  

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