Scientists have found a way to make wood glow in the dark, creating an “innovative hybrid material” that can potentially serve as a fully sustainable light producer used to power streets, homes and offices. That is according to Swiss researchers from Empa’s Cellulose & Wood Materials lab, who successfully fused white rot fungus D. tabescens with balsa wood to make the bright green material.
Led by Francis Schwarze, the study – Taming the Production of Bioluminescent Wood Using the White Rot Fungus Desarmillaria Tabescens – saw the researchers combine honey fungus, a potent producer of luciferin that gives mushrooms their foxfire glow, with balsa wood—chosen for its low density—to create bioluminescent fungi, a glowing material described by Aristotle and Pliny 2,400 years ago.
“The main reason for this is that the balance between the choice of fungal species, wood species, its moisture content and the environmental conditions required to produce bioluminescent wood is very challenging,” Schwarze said in the study. Soaking wooden blocks in water for three months with a specific moisture content of 700-1,200% before co-cultivating them with the fungus produced the desired effect, “highlighting the fundamental role of moisture” for bioluminescence production.
“Our studies show that the moisture content of wood, presence of oxygen, amount of lignin and malt as an energy source, all strongly influence the intensity of bioluminescence,” Schwarze said, adding that over the incubation period, “the balsa wood sample absorbed eight times their weight.”
When it came into contact with air, it triggered a chemical reaction involving caffeic acid that made the wood reach its maximum bright green in ten hours before glowing for 10 days: “Unlocking these bioluminescent mechanisms could bring an electricity-free light source with a low-energy requirement into the world for human consumption,” Schwarze said.
But first, the researchers must keep developing the material to enhance its intensity and prolong its effect. This includes ensuring that future materials possess “smart” capabilities, including the ability to self-heal, respond to their environment, and change state.
“We have shown that with knowledge of the wood substrate and its moisture content and by manipulating the environmental conditions…(that) we can make it possible to trigger and standardize bioluminescence emission. Unlocking the mechanisms behind fungal bioluminescence could provide an electricity-free light source for the future with a low energy requirement.”
“A battery-free or plug-free sustainable light source based on bioluminescent fungi would benefit the environment and help us meet net-zero targets in line with the Intergovernmental Panel on Climate Change (IPCC). Utilizing bioluminescence to illuminate our homes and communities would result in energy savings and a reduction in CO2 emissions.”
“The alternative light source would also reduce nighttime light pollution, a global concern in large cities. For example, at Benjamin Franklin’s suggestion, bioluminescent wood was used to illuminate the compass and depth gauge of the first submarine, the Turtle.”
