It sounds like something out of a fairy tale — but it’s real. In the northern forests of Finland, scientists have discovered that some spruce trees are producing tiny particles of gold inside their needles.
Yes, you read that right. Certain trees don’t just make oxygen — they also make nanoparticles of gold, thanks to microscopic life hidden deep within their leaves.
When microbes turn trees into gold factories
In the chilly boreal forests of northern Finland, researchers studying the Norway spruce stumbled on something incredible : minute specks of gold nestled inside the trees’ needles. But the trees weren’t mining the earth on their own.
The secret, it turns out, lies in their microbial partners. Scientists have long known that bacteria living inside plants can change their internal chemistry, but this is the first time anyone has connected those microbes to the creation of actual gold particles.
According to postdoctoral researcher Kaisa Lehosmaa from the University of Oulu, “Our findings suggest that bacteria and other microbes living inside plants can influence the accumulation of gold in trees.”
That simple sentence could change the way we look for gold — and even how we clean up polluted water.
How gold moves from the ground to the treetops
The study focused on spruces growing above a known gold deposit in Finnish Lapland, near the Kittilä mine, one of Europe’s largest gold operations. When rocks underground begin to oxidize, they release ions — including trace metals like gold — into the surrounding soil and groundwater.
As trees absorb water through their roots, those ions hitch a ride, moving upward into the leaves and needles. Using ultra-sensitive instruments, scientists can even detect metal traces in snow or plant tissues, giving clues about what lies beneath the forest floor.
To test the theory, Lehosmaa and her team collected 138 needle samples from 23 different trees. They split their research into two parts : one using advanced electron microscopy to hunt for gold, and another analyzing the DNA of bacteria living inside the needles.
Out of the 23 trees, four contained visible gold nanoparticles — each one confirmed by its distinct X-ray signal. And here’s the fascinating part : the gold tended to cluster near bacterial biofilms, the sticky layers microbes build to protect themselves and live together.
The tiny bacteria behind the glitter
When the scientists sequenced the DNA inside those biofilms, a pattern emerged. Certain types of bacteria — such as Cutibacterium, Corynebacterium, and a lesser-known group called P3OB-42 — were far more common in the gold-rich needles.
That link suggests these specific microbes might be transforming soluble gold ions into solid particles inside the tree’s tissues. “These spruce-specific bacteria may play a role in turning dissolved gold into nanoparticles,” says Dr. Lehosmaa.
It’s a remarkable thought: inside the quiet stillness of a forest, bacteria are literally making gold — one atom at a time.
Here’s how it likely happens. Gold in the soil exists in a soluble, liquid-like form, traveling with water through the roots. Once it reaches the needles, the chemical environment created by microbial biofilms changes the gold’s state, making it less soluble. That process triggers the formation of microscopic, solid particles — tiny flecks of gold that stay trapped within the leaf.
Plants naturally try to isolate metals to keep their systems running smoothly, while microbes use the same environment to capture useful trace elements. It’s a delicate dance of biology and chemistry happening high above ground.
What this means for gold exploration and beyond
Not every spruce contained gold, which makes sense. Each tree draws water differently, and their microbiomes — the unique communities of bacteria inside them — vary from branch to branch. But where gold did appear, the needles often had fewer bacterial species overall, hinting that certain microbes dominate when metal is present.
The implications are huge. For decades, geologists have used biogeochemical exploration, sampling plants to find buried mineral deposits. This new research adds a powerful twist: instead of just analyzing what metals are inside the leaves, scientists can now look at which bacteria are there too.
Imagine scanning forests not just for chemical traces, but for microbial fingerprints that point to gold underground. That could mean fewer blind drilling projects, less environmental damage, and a much cleaner way to find new deposits.
As research scientist Maarit Middleton from the Geological Survey of Finland puts it, “This new study improves our understanding of what’s actually happening inside the process.”
It’s not just about prospecting either. The same microbial chemistry that helps trees capture gold could also help clean metal-contaminated water near mining sites. If biofilms and plant tissues can turn dissolved metals into solids, they could be harnessed to remove pollutants naturally — a kind of green, living filter for industrial waste.
So next time you walk through a forest, take a closer look at the trees around you. Somewhere out there, hidden in the still air between the branches, nature is quietly making gold — and reminding us that even the most ordinary things can hide extraordinary secrets.
What do you think ? Should scientists use living plants to help find or clean up metals ? Share your thoughts, pass this along to a friend who loves science, and let’s keep the conversation growing — just like those golden trees in Finland.
