How Fungal Bioluminescence Works: The Science Explained

When you wander through a damp forest at night, you might spot a faint blue‑green glow coming from dead wood. That glow is fungal bioluminescence, a natural phenomenon where certain fungi emit visible light through a chemical reaction.

The light comes from an enzyme called luciferase that oxidises a small molecule known as luciferin. The reaction uses oxygen and a co‑factor such as NADPH to produce excited‑state molecules that release photons as they relax.

In most glowing mushrooms the light is generated not by the fruiting body but by the mycelium, the thread‑like network that spreads through soil and wood.

Among the over 70 known glowing species, Neonothopanus nambi (the “Jack‑o’‑lantern fungus” of Southeast Asia) and Omphalotus olearius (the “Jack‑o’‑lantern mushroom” of Europe and North America) are the most intensively studied.

Fungal bioluminescence has sparked both curiosity and practical ideas, from night‑time forest tours to sustainable lighting concepts.

What makes mushrooms glow?

The glow originates from a biochemical pathway that is remarkably similar to the one used by fireflies, yet it evolved independently in fungi. The core steps are:

1. Luciferin is synthesized inside the fungal cells.
2. Luciferase binds to luciferin and oxygen.
3. The enzyme catalyses oxidation, releasing energy.
4. Energy excites a molecule that, when it returns to its ground state, emits a photon.

Because the reaction occurs continuously at low intensity, the overall effect is a soft, steady glow rather than a flash.

The luciferin-luciferase chemistry

Research led by the University of Queensland identified the exact chemical structure of fungal luciferin as a 3‑hydroxy‑hispidin derivative. The corresponding luciferase, a flavin‑dependent mono‑oxygenase, belongs to a distinct protein family not found in animals.

The overall reaction can be summarised by the following simplified equation:

Hispidin + O₂ + NADPH -[luciferase]→ Oxyluciferin* + NADP⁺ + H₂O → Light (λ≈520nm)

*The asterisk denotes the excited state.

Key glowing species

All three species share the same luciferin‑luciferase system, but subtle variations in enzyme structure shift the emission wavelength, producing different colours.

Why do fungi glow? Ecological theories

Scientists have proposed three main explanations:

• Attracting insects: The glow may draw in nocturnal insects that help disperse fungal spores, similar to how fireflies use light for mating signals. Field experiments with Omphalotus olearius showed higher spore deposition near illuminated fruiting bodies.
• Oxidative stress mitigation: The luciferase reaction consumes excess reactive oxygen species generated during wood decay, acting as a biochemical safety valve.
• Warning signal: Some predators avoid brightly glowing objects, assuming they are toxic. The orange‑yellow glow of O. olearius could serve as a visual deterrent.

Current evidence favours the insect‑attraction hypothesis, but the other mechanisms likely contribute under different environmental conditions.

From lab to lab: Harnessing fungal light

In 2023 a team at MIT used CRISPR to insert the fungal luciferase gene cluster into Saccharomyces cerevisiae. The engineered yeast glowed autonomously without adding external substrates, opening doors for bio‑lighting in low‑tech settings.

Commercial interest is growing. Start‑ups are testing glow‑mushroom installations for eco‑friendly garden décor and for low‑energy signage that runs on the fungus’s own metabolism.

Research methods and recent breakthroughs

Modern studies combine genomics, proteomics and imaging:

• RNA‑seq has uncovered the entire set of genes up‑regulated during the glowing phase.
• CRISPR‑Cas9 knock‑out experiments confirm that disabling the luciferase gene abolishes light emission.
• Bioluminescence microscopy allows scientists to watch the glow spread through mycelial networks in real time.

In 2024, a longitudinal field study in Borneo tracked Neonothopanus nambi over two years, revealing that the fungus glows most intensely during the rainy season when wood decay rates-and thus oxidative stress-peak.

Key takeaways

• Fungal bioluminescence is driven by a luciferin‑luciferase oxidation that emits photons around 520nm.
• The pathway is genetically encoded and shares functional themes with firefly lighting, but uses unique enzymes.
• Glowing species likely use light to attract insects, mitigate oxidative stress, or warn predators.
• Biotechnologists are already moving the glow genes into other organisms for sustainable lighting solutions.
• Ongoing research combines genome editing, transcriptomics and real‑time imaging to deepen our understanding.