Tag: fungi

Future computers could grow their own memory – from mushrooms

Computers run on silicon and metal. Mushrooms grow in soil. Yet now, scientists are finding that one could stand in for the other.

Fungi might replace parts of the machines that shape our digital world. The idea sounds strange until you realize how intelligent and resilient these organisms are.

Mushrooms in computing

At The Ohio State University, researchers found that edible mushrooms such as shiitake could act like organic memory chips. When connected to circuits, the mushrooms stored and processed information like a living brain.

Study lead author John LaRocco is a research scientist in psychiatry at Ohio State’s College of Medicine.

“Being able to develop microchips that mimic actual neural activity means you don’t need a lot of power for standby or when the machine isn’t being used,” said LaRocco.

The fungal chips performed surprisingly well. Each could switch electrical states thousands of times per second with high accuracy.

These organic systems did not rely on costly rare-earth minerals or energy-intensive factories, which makes them an appealing alternative to traditional semiconductors.

Learning from nature

Fungi already form vast underground networks that pass signals between roots and trees. The researchers realized these same biological systems could be repurposed to store information.

The mycelium – the thread-like part of a fungus – responds to electrical pulses by changing its resistance. Those shifts act like memories.

In tests, mushrooms adjusted their conductivity when exposed to repeated voltage cycles. Their ability to change behavior after each signal mirrored how neurons in the brain learn.

Over time, the fungi “remembered” patterns of stimulation and became more stable in performance. That self-tuning nature could one day lead to energy-efficient devices that learn continuously, much like biological systems.

Testing mushrooms for computers

To explore this, the team grew shiitake and button mushrooms on organic materials such as wheat germ, hay, and farro seeds.

Once the fungal mats reached maturity, they were dried in sunlight to maintain shape and later sprayed with water to restore conductivity.

“We would connect electrical wires and probes at different points on the mushrooms because distinct parts of it have different electrical properties,” said LaRocco.

Each part responded differently to signals, showing that the internal structure of mushrooms influences how electricity flows.

At specific frequencies, the fungi displayed classic memory loops known as hysteresis curves, confirming their potential as memristors.

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This fungus grows more vigorously when it feels good vibes

Blasting your favorite playlist can energize your workout. The same is true of fungus—although most people might find its tastes in tunes a bit strange. Fungal soil microbes may get a boost of energy from white noise, according to new research that found the microbes exposed to a particular sound frequency in the lab grew faster. Scientists say they hope the findings, out today in Biology Letters, could lead to sonic techniques that spur the growth of microbes that play critical supportive roles in plant microbiomes, helping rejuvenate stressed ecosystems.

“As humans, we think of sound as an airborne stimulus that we hear,” says Richard Hofstetter, a forest entomologist at Northern Arizona University who was not involved with the study. Other animals respond to sound, too. But even plants and single-celled organisms that can’t “hear” can feel the vibrations. “They don’t have ears or nerves,” he says, but they seem to respond to the mechanical energy that comprises sound. “It’s an energy similar to light,” he says.

Hofstetter’s research has shown a mold called Botrytis cinerea, which grows on fruit including strawberries, gets a growth boost from the acoustic vibrations of refrigerators. Sound has also been shown to boost the growth of Escherichia coli. Both these studies used frequencies of a few thousand hertz (Hz), a high-pitched humming sound the microbes seemed to dig. Other work has shown leaf-dwelling microbes that produce desirable flavor compounds in wine made from Syrah grapes respond to music from the Baroque and early Classical eras.

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Out of Sight, ‘Dark Fungi’ Run the World from the Shadows

If you want to discover a hidden world of new life-forms, you don’t have to scour dark caves or slog through remote rainforests. Just look under your feet. When then-graduate student Anna Rosling went to northern Sweden to map the distribution of a particular root-loving fungus, she found something much more intriguing: Many of her root samples contained traces of DNA from unknown species. Weirder still, she never encountered a complete organism. When the field season ended, she had only isolated bits of raw genetic material. The fragments clearly belonged to the fungal kingdom, but they revealed little else. “I got obsessed,” recalls Rosling, now a professor of evolutionary biology at Uppsala University in Sweden.

Since then mycologists have realized that such phantoms are everywhere. Point to a patch of dirt, a body of water, even the air you’re breathing, and odds are that it is teeming with mushrooms, molds and yeasts (or their spores) that no one has ever seen. In ocean trenches, Tibetan glaciers and all habitats between, researchers are routinely detecting DNA from obscure fungi. By sequencing the snippets, they can tell they’re dealing with new species, thousands of them, that are genetically distinct from any known to science. They just can’t match that DNA to tangible organisms growing out in the world.

These slippery beings are so widespread that scientists are calling them “dark fungi.” It’s a comparison to the equally elusive dark matter and dark energy that make up 95 percent of our universe and exert tremendous influence on, well, everything. Like those invisible entities, dark fungi are hidden movers and shakers. Scientists are convinced they perform the same vital functions as known fungi, directing the flow of energy through ecosystems as they break down organic matter and recycle nutrients. Dark fungi are prime examples of what biologist E. O. Wilson called “the little things that run the world.” But their cryptic lifestyle has made it a maddening challenge for scientists trying to show how exactly they run it.

Taxonomists have described just 150,000 of the millions of fungi predicted by global biodiversity estimates, and recent discoveries suggest a huge portion of what’s left may be off-limits to routine biological investigation. “We have not even started to scratch the surface,” says Henrik Nilsson, a mycologist at the University of Gothenburg in Sweden. “I’d be willing to bet that the clear majority will be dark.” Given the central place of fungi in the web of life that sustains us, experts argue we should get a better grasp on them.

Everything we know about dark fungi comes from environmental DNA, or eDNA. That term refers to strings of base pairs—the building blocks of DNA that are constantly sloughing off all living things. Researchers can analyze these free-floating bits of double helix to determine which species have been hanging around an area without seeing them. To identify fungi specifically, scientists look to a handy genetic marker called the internal transcribed spacer (ITS), which consists of several hundred base pairs that evolve quickly and thus help distinguish between species. Although the ITS is only a tiny fraction of the genome, researchers can single it out and amplify it with the same polymerase chain reaction technology used in COVID lab tests. If an ITS sequence is different enough from all others in genetic databases, it is thought to represent a new species, whether scientists lay eyes on its physical form or not.

At the turn of the millennium, eDNA sequencing burst onto the scene as a new way to discover species. Scientists suddenly found themselves awash in a “flood of data,” as David Hibbett, a mycologist at Clark University, and his colleagues wrote in 2009. That influx exposed the sheer vastness of dark fungi. Today, Hibbett says, “our understanding of the richness of fungal diversity is really being enlarged with these dark organisms.”

Every year researchers stumble on some 2,000 new fungi via the standard route, spotting them in nature or under a microscope. Yet a single eDNA study can register 10 times more dark fungi than that. As often as not, the fragments are among the most abundant DNA samples in their ecosystem. “I don’t think I ever saw an environmental sequencing study with less than 30 percent unknowns,” Nilsson says, and the ratio is typically much higher. Sometimes only a minority of DNA sequences can be classified at any meaningful taxonomic level, narrowing them from a kingdom (in this case, fungi) to a phylum and then to a class, and so on down to a species.

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