How genetically-engineered bacteria could one day be used to ‘grow’ biodegradable paints

Scientists have managed to change the colour of a certain type of bacteria by genetically mutating them.

They believe this technology could be used to “grow” biodegradable, non-toxic paint in the future.

Flavobacteria, which are rod-shaped bacteria that form colonies and are found in soil and fresh water in a variety of environments, are known to put on striking metallic colour displays.

These metallic colours do not come from pigments but from their internal colony structure, which reflects light at certain wavelengths.

Using genetic engineering technologies, the researchers from the University of Cambridge and Dutch company Hoekmine BV were able to change the shape and size of a type of Flavobacteria known as Flavobacterium IR1. This in turn, altered the geometry of their colony structure.

The geometric alteration caused the bacterial colony, which was originally a metallic green, to change colour. The team was able to make them appear virtually any colour in the visible spectrum, from blue to red.

First author Villads Egede Johansen, from Cambridge’s Department of Chemistry, said: “This is the first systematic study of the genes underpinning structural colours – not only in bacteria but in any living system.”

The researchers say these engineered bacterial colonies could one day be used to grow organic, biodegradable and non-toxic paints and coatings.

Co-senior author Dr Silvia Vignolini, also from Cambridge’s Department of Chemistry, said: “We see a potential in the use of such bacterial colonies as photonic pigments that can be readily optimised for changing colouration under external stimuli and that can interface with other living tissues, thereby adapting to variable environments.

“The future is open for biodegradable paints on our cars and walls – simply by growing exactly the colour and appearance we want!”

The paper is published in the journal PNAS.