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BBC – Future – The unexpected magic of mushrooms



There is a monster under Jim Anderson & # 39; s feet. It has lived since the Persian King Xerxes war fought against the ancient Greeks and weighs more than three blue whales together. It has a voracious appetite and eats its way through huge tracts of forest. But this is not a long-forgotten beast carried by Greek mythology. It is a mushroom.

Anderson stands in a modest stretch of forest in Crystal Falls, on the Upper Peninsula of Michigan. He is busy visiting an organism that lives under the forest floor that he and his colleagues discovered almost 30 years ago. This is the home of Armillaria gallica, a kind of honey mushroom.

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These common fungi occur in temperate forests throughout Asia, North America and Europe, where they grow on dead or dying wood and help accelerate decay. Often the only visible sign of them above ground is clumps of flaky, yellowish-brown mushroom-like fruiting bodies that grow up to 10 cm high.

When Anderson and his colleagues visited Crystal Falls in the late 1980s, they discovered that what initially appeared to be a rich community of Armillaria gallica flowering under the mulch of leaf waste and the top soil of the forest floor was – in fact – a gigantic individual specimen. They estimate that it covered an area of ​​approximately 91 hectares, weighed 100 tons and was at least 1500 years old. At the time, it set a new record for the largest organism in the world – a similar fungus in a forest in Oregon now has the record.

"It caused quite a stir at the time," Anderson says. "Our newspaper came out on April Fool & # 39; s Day so everyone thought it was a joke. Then, in 2015, we thought we should go back and test our prediction that this was really a persistent, single organism."

The new results showed that it was four times larger, 1000 years older and if it were collected together, it would weigh around 400 tonnes

They returned to the site several times between 2015 and 2017, took samples from distant points in the forest and then ran the DNA that they had collected through a sequencer in their laboratory at the University of Toronto. Since their first study in the 1980s, genetic analysis has progressed in large numbers, with new techniques that make the process much cheaper, faster and provide more information.

Their new monsters not only revealed that Armillaria gallica they had discovered one individual, but it was much larger and older than they had predicted. The new results showed that it was four times larger, 1000 years older, and if it were collected together, it would weigh around 400 tonnes.

But the analysis provided an even more surprising insight, one that could help us humans in our fight against one of the greatest enemies of modern medicine – cancer.

The Canadian researchers discovered what might be the secret behind the Armillaria gallica& # 39; Normal size and age. It seems that the fungus has an extremely low mutation rate – meaning that it avoids potentially harmful changes to the genetic code.

As organisms grow, their cells divide into two to produce new daughter cells. Over time, the DNA in the cells can be damaged, leading to errors known as mutations that creep into the genetic code. This is considered to be one of the most important mechanisms that cause aging.

But it looks like it Armillaria gallica in Crystal Falls may have some resistance to this DNA damage. In 15 samples taken from distant parts of the forest and the order of the team, only 163 letters out of 100 million in the genetic code of Armillaria gallica is changed.

The fungus has a mechanism that helps protect its DNA from damage, making it one of the most stable genomes in the natural world

"The mutation frequency is much, much lower than we could have ever imagined," Anderson says. "To have this low level of mutation, we would expect the cells to divide on average once for every meter of growth. But what is amazing is that the cells are microscopically small – only a few micrometers in size – so you would need millions in every meter of growth. "

Anderson and his team believe that the fungus has a mechanism that helps protect its DNA from damage, making it one of the most stable genomes in the natural world. While they still have to unravel what exactly this is, the remarkable stability of the genome is Armillaria gallica could offer new insights into human health.

In some cancers, cell mutations can revive because the normal mechanisms that control and repair DNA break down.

"Armillaria gallica can be a potential counterpoint to the notorious instability of cancer, "Anderson says." If you looked at a line of cancer cells that were the same in age, it would be so permeated with mutations that you probably wouldn't be able to recognize it. Armillaria is the opposite extreme. Perhaps it is possible to pick out the evolutionary changes that have made it possible to compare this with cancer cells. "

By doing this, scientists can not only learn more about what goes wrong in cancer cells, but also offer potential new ways to treat cancer.

Although Anderson and his colleagues don't intend to do this work themselves – they leave it to others who are younger and more qualified to understand the genetic complexity of cancer – their findings offer an intriguing view of the untapped power of fungi to help humanity.

The combined biomass of fungi surpasses that of all the animals on the planet combined

Fungi are some of the most common organisms on our planet – the combined biomass of these often small organisms exceeds that of all the animals on the planet combined. And we discover new fungi all the time. More than 90% of the estimated 3.8 million fungi in the world are currently unknown to science. In 2017 alone, 2,189 new species of fungi had been described by scientists.

A recent report published by the British Royal Botanic Gardens Kew in London emphasized that fungi are already used in hundreds of different ways, from making paper to helping clean our dirty clothes. About 15% of all vaccines and biologically produced drugs come from fungi. For example, the complex proteins used to trigger an immune response to the hepatitis B virus are grown in yeast cells that are part of the fungal family.

Perhaps the best known is the antibiotic penicillin, which was discovered in a common form of household fungus that often grows on stale bread. Dozens of other types of antibiotics are now produced by fungi.

They are also sources of treatments for migraine and statins for the treatment of heart disease. One relatively new immunosuppressant, used to treat multiple sclerosis, was developed based on a compound produced by a fungus that infects cicada larvae.

"It is part of this family of fungi that crawls into insects and takes them over," says Tom Prescott, a researcher who evaluates the use of plants and fungi at the Royal Botanic Gardens Kew. "They produce these compounds to suppress the immune system of insects and it appears that they can also be used in humans."

But some researchers believe that we have barely scratched the surface of what fungi can offer us.

Compounds produced by fungi can destroy viruses that cause diseases such as flu, polio, mumps, measles and glandular fever.

"There have already been [fungi] reportedly activity against viral diseases, "says Riikka Linnakoski, a forest pathologist at the Natural Resources Institute Finland. Fungi-produced compounds can destroy viruses that cause diseases such as flu, polio, mumps, measles, and glandular fever. Numerous fungi also appear produce compounds that could treat diseases that are not currently cured, such as HIV and the Zika virus.

"I believe these are only a small part of the full arsenal of bioactive compounds," says Linnakoski. "Fungi are a huge source of various bioactive molecules that could potentially be used as antiviral agents in the future."

She is part of a research team that investigates whether fungi that grow in the mangrove forests of Colombia can be sources of new antiviral agents. However, these goals have not yet been achieved. Although fungi have been well researched as a source of antibiotics that act on bacteria, no antiviral drugs derived from fungi have been approved.

Linnakoski calls this apparent omission of the scientific community to the difficulty of collecting and growing many fungi from the natural environment and the historical lack of communication between mycologists and the virological community. But she believes it will only be a matter of time before a fungal-based antiviral drug ends up in clinics.

Linnakoski also believes that searching for new fungal species in inhospitable environments such as in the sediment on the seabed in some of the deepest parts of the ocean, or in the highly changeable conditions of mangrove forests, can provide even more exciting connections.

"The extreme conditions are thought to provoke fungi to produce unique and structurally unknown secondary metabolites," she says. "Unfortunately, many of the original ecosystems with great potential for discovering new bioactive substances, such as mangrove forests, are disappearing in disturbing numbers."

A fungus that grows in the soil at a landfill on the outskirts of Islamabad, Pakistan can quickly break down polyurethane plastic

But fungi have applications that can tackle other problems outside of our health.

A fungus that grows in the soil at a landfill on the outskirts of Islamabad, Pakistan can be a solution to the alarming levels of plastic pollution that clogs our oceans. Fariha Hasan, a microbiologist at Quaid-I-Azam University in Islamabad, discovered the fungi Aspergillus tubingensis can quickly break down polyurethane plastic.

These plastics, which used to make a wide range of products, including furniture foams, electronics cases, adhesives and films, can remain in soil and seawater for years. However, the fungi were broken down within a few weeks. Hasan and her team are now investigating how they can use the fungi for large-scale demolition of plastic waste. Other fungi, such as Pestalotiopsis microspore, which normally grows on rotting ivy leaves, also appears to have an enormous appetite for plastic, which raises the hope that they can be used to tackle our growing waste problem.

Mushrooms even have a decent taste for the pollution with which we contaminate our world. Species have been discovered that can clean up oil pollution from the soil, destroy harmful heavy metals, use persistent pesticides and even help rehabilitate radioactive sites.

However, mushrooms can also help prevent the use of plastic in the first place.

A number of groups around the world are now trying to use an important feature of fungi – the vein-like webs of mycelium that they produce – to make materials that can replace plastic packaging. As fungi grow, these mycelium threads branch out to examine and bind the corners and holes in the soil. They are nature's glue.

In 2010, Ecovative Design began researching how they could use this to merge natural waste products such as rice husks or wood chips into an alternative to polystyrene packaging. Their early work has evolved into MycoComposite, which uses remains of hemp plants as the basic material.

These are packaged in reusable molds together with mold spores and flour, which are then grown for nine days. As they do this, they produce enzymes that will digest the waste. Once the material has grown into the desired shape, it is then heat treated to dry out the material and stop further growth. The resulting mushroom package is biodegradable and is already being used by companies such as Dell to package its computers.

The company has also developed a way to develop mycelium into foams that can be used in trainers or as insulation, and fabrics that mimic leather. Working with sustainable fabrics, Bolt Threats, combines waste corn stalks with the mycelium, allowing it to grow into a mat that is tanned and compressed. The entire process takes days instead of the years required for animal learning.

Stella McCartney is one of the designers looking for this mushroom leather and shoe designer Liz Ciokajlo has recently used mycelium to create a modern resuscitation of the fashion trend of the & # 39; 70 Moon Boot.

It is possible to match the properties of the mycelium material by changing what it needs to digest

Athanassia Athanassiou, a material scientist at the Italian Institute of Technology in Genoa, has used fungi to develop new types of dressings for the treatment of chronic wounds.

But she has also discovered that it is possible to match the properties of the mycelial material by changing what it has to digest. The harder a substance is for the fungi to digest – such as wood chips instead of potato peels – the stiffer the resulting mycelial material, for example.

It increases the prospect of using fungi for more robust purposes.

MycoWorks from California has developed ways to turn mushrooms into building materials. By fusing wood with mycelium, they are able to make bricks that are fire-resistant and harder than conventional concrete.

Tien Huynh, a biotechnologist at the Royal Melbourne Institute of Technology in Australia, led a project to make similar fungal stone by combining mycelium from Trametes versicolor with rice husks and crushed waste glass.

She says they not only provide a cheap and environmentally-friendly building material, but they also help solve another problem that many homes in Australia and the rest of the world face — termites. The silicon dioxide content of the rice and glass makes the material less tasty for termites, which cause billions of dollars in house damage every year.

"In our research, we also used the fungi to produce enzymes and new biostructures for different properties, including sound absorption, strength and flexibility," says Huynh. Her team is also working on the use of fungi to produce chitin – a substance used to thicken food and in many cosmetics.

"Chitin is usually processed from shellfish, which has hypoallergenic properties," she says. "The fungal chitin does not do that. There will be more fungal-based products later this year, but it is certainly a fascinating resource that is under-utilized."

Fungi can also be used in combination with traditional building materials to create a "smart concrete" that can heal itself as the fungi grow into cracks that form and which separate fresh calcium carbonate – the main raw material in concrete – to repair the damage .

"The possibilities for which we can use mycelium are endless," says Gitartha Kalita, bio-engineer at Assam Engineering College and Assam Don Bosco University in Guwahati, India. He and his colleagues used molds and hay loss to create an alternative to wood for construction. "Everything that we now call agricultural waste is actually an incredible resource that mushrooms can grow on. We have already deteriorated our environment and so if we can replace current materials with something that will sustainably sustain. They can take our waste with us and changing into something that is really valuable to us. "

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