Researchers have created a paint containing living cyanobacteria that produces oxygen and can capture carbon dioxide. The bacteria’s ability to withstand extreme environments means this novel paint could be used in a range of applications, including outer space.
The rise in greenhouse gases and the resulting climate crisis have led scientists to think outside of the box when it comes to sequestering carbon dioxide. We’ve already seen cyanobacteria, or blue-green algae, proposed as a component of new, green materials because of their photosynthetic properties.
Cyanobacteria fix carbon dioxide to transform it, via photosynthesis, into organic compounds and can do so with high efficiency in adverse environments. Moreover, they grow quickly and can be genetically modified in most cases.
Now, researchers from the University of Surrey in the UK have developed an oxygen-producing, carbon dioxide-absorbing water-based paint containing a species of cyanobacteria, something they’re calling 'green living paint.'
“With the increase in greenhouse gases, particularly carbon dioxide, in the atmosphere and concerns about water shortages due to rising global temperatures, we need innovative, environmentally friendly, and sustainable materials,” said Suzie Hingley-Wilson, corresponding author of the study. “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.”
The researchers set out to immobilize metabolically active – viable – cyanobacteria in a porous yet mechanically hard coating to fix carbon and evolve oxygen. They compared three species of cyanobacteria and found that Chroococcidiopsis cubana performed the best. C. cubana is a strain that’s ‘extremophilic,’ meaning it can withstand extreme temperatures and pH levels, high salt concentrations, arid environments, and radiation.
The process was relatively simple. The researchers immobilized the cyanobacteria in a biocoating made from polymer particles in water, which was fully dried and rehydrated. They found that, compared to the other species used, the Chroococcidiopsis remained viable, and the rate of oxygen production steadily rose, reaching maximum levels of 0.4 g of oxygen per gram of biomass per day. Continuous measurements of dissolved oxygen over a month showed no sign of decreasing activity. They estimated that carbon capture was 0.31 g of carbon dioxide per gram of biomass per day.
The researchers say their findings suggest that extremophilic cyanobacteria are ideal candidates for use in biocoatings and other biotechnology, including in outer space.
“The photosynthetic Chroococcidiopsis have an extraordinary ability to survive in extreme environments, like droughts and after high levels of UV radiation exposure,” said Simone Krings, the study’s lead author. “This makes them potential candidates for Mars colonization.”
Future research will concentrate on optimizing the use of this strain of cyanobacteria as a biocoating.
The study was published in the journal Microbiology Spectrum.
Source: University of Surrey
