Celebrating fungi: Why mushrooms and their relatives matter
This is a nod to the humble mushroom. It is a celebration of fungi.
Mushrooms are one of my least liked foods, and perhaps because of that, I don’t have a keen eye for wild fungi and couldn’t tell a Stinkhorn from a Death Cap, or a Cauliflower Fungus from a Chicken of the Woods.
But to get a quick idea of how glorious fungi can be - watch this clip below of fungi in the tropics, narrated by the BBC's own Sir David Attenborough.
Also, two bits of news remind me that among these humble life forms exist some of the most important, influential and vulnerable species on Earth; ones that have been ignored for too long.
The first is research published about a group of fungi known as “black yeasts”.
Black yeasts are generalist fungi – they are good at adapting to a variety of environments. Compared to other fungi, black yeasts can live at high temperatures, in acidic and alkaline environments and survive without water. Their cell walls contain high levels of melanin, a dark pigment producing their black appearance. That makes them resistant to antifungal agents. And remarkably, they can switch shape, growing as filaments, or more like conventional yeast, and then can form difficult to shift biofilms that adhere to surfaces.
They also like to come into our homes.
Domestic environments are, almost by definition, unnatural, stressful places for wildlife. Any fungi entering has to contend with unfavourable conditions – temperatures are kept artificially high, we don’t let water run freely around our houses, and we coat them in unusual substrates and chemicals, such as silicone rubber and disinfectants.
Black yeasts appear to have taken on this challenge: black fungi Cladosporium halotolerans and Aurebasidium pullulans have been found in Arctic glacial ice, and on bathroom surfaces, as both habitats are characterised by periods of extremely low water availability.
By living in our houses, these yeasts may be becoming even more stress tolerant, with potentially severe implications for our health. People are already known to have caught infections of black fungi from their bathrooms, while several species of the genus Exophilia cause various diseases including infections of the feet, nails and brain. Exophilia species have been found in domestic steam baths, drinking water and have just been found lurking in dishwashers.
For example, say Cene Gostinčar and colleagues in the journal Functional Biology, as black yeasts adapt to grow at higher temperatures they may become more likely to colonise warm-bloodied organisms – meaning us. By cranking up the heat, keeping rooms dry and using more disinfectants, we may be unwittingly selecting for new strains of disease-causing fungi that will be even harder to eliminate.
“We might have turned our homes into microcosms for the experimental evolution of the most resilient of microbial species, the adaptability of which might enable them to find new niches in the human body,” Gostinčar’s team writes.
How significant a problem this may be remains to be seen and the scientists’ warning shouldn’t be immediately turned into a medical scare story.
But it highlights the adaptability of this remarkable group of organisms, and how little we still know about them.
Which brings me to the second piece of news.
Fungi, the world over, are in danger of going extinct. Yet very few people of aware of them, or their plight.
Part of this lack of awareness is that fungi are often thought to be boring, even though the Hat Throwing Fungus is the fastest living thing on the planet (see it for yourself in the embedded video below), while there are more than 3,000 different types of mushrooms and toadstools in the UK alone.
Another key reason is that fungi are not included in the global IUCN Red List of Threatened Species, the most definitive and relied upon guide to species facing extinction.
Many other species groups are badly represented on the IUCN Red List - for example, though it includes over 12,000 plant species, fewer than one thousand are properly documented.
But fungi are all but absent.
Of the 17,291 animal, plant and fungal species that are globally redlisted, only one macrofungus, (the Critically Endangered White Ferula Mushroom) and two fungi that help form lichens (the Endangered Florida Perforate Reindeer Lichen and Critically Endangered Boreal Felt Lichen) are included.
There is no doubt that fungi populations are harder to survey and some mycologists aren’t sure to what extent it can be done.
Yet on a national level, more than 15,000 species of fungi have been evaluated. In those countries where extensive surveys have been conducted, 20-60% of macrofungal species are thought to be threatened.
This disconnect between national and international red lists means that fungi have essentially become missing from the conservation debate, say researchers Anders Dahlberg and Gregory Mueller in the journal Fungal Ecology.
Considering there may be more than 1.5 million species of fungi, 95% of which have yet to be formally described by science, thousands or maybe hundreds of thousands of fungi species may face an uncertain future.
So here’s to putting humble fungi back on the agenda.
Let’s celebrate their glorious shapes and glorious names; from the Apricot Jelly Mushroom, Fuzzy Foot, and Satan’s Mushroom, to the Artist’s Conk, Scrambled Egg Slime and Chocolate Chip Lichen.
And let’s give them some more attention before it’s too late. If we don’t, you can be sure that some species, such as the black yeasts, may soon demand it.