Cryophile Files: Fungi fight frost with slime

Winter is inevitable. The forecast calls for lows in the 30s this week. Soon my oil-run monitor will heat my cabin 24/7 and Starvation Gulch likely will, as always, be accompanied by the first snow.

The nip of frost is a nuisance for humans, but we forget how precarious the freezing point of water is for those without warm clothes and cozy homes.

Interior Alaska is a hotbed of cold-loving life. Fairbanks is a community that embraces the inevitable.

This brings me to a new series, a celebration of Alaska’s eccentric adaptations to cold.

In the microbial world, cryophiles are those odd types that, despite all other habitats available, adore living in frigid climes. Scientists here study what makes cold-loving beings tick, what small differences allow them to outlast their peers – and why they came here at all.

I find myself defending these voiceless archetypes, as if the question is an attack against the quintessential Fairbanks spirit. We thrive here because the boreal forest is ours, and ours alone.

There’s a group of substances known as antifreeze proteins. They essentially do the same job as the antifreeze in your car by tampering with the freezing point of water. These proteins have a number of commercial uses. Good Humor-Breyers has been known to use the antifreeze proteins of the arctic kidney lichen (Nephroma arcticum) to keep the texture of their ice creams constant. (Here’s the Wikipedia link if you don’t have journal access)

The 32nd flavor. Nephroma arcticum covers the base of a spruce tree off the Parks Highway. June 19.

This time of year everything’s preparing for slumber. Leaves cover the ground, squirrels horde like never before, late-season mushrooms … proliferate?

Cold-tolerance is at work here.

Scientists and enthusiasts list a number of reasons why some mushrooms are covered in slime, but everyone agrees that it’s a life-preserving tactic. UAF researcher Gary Laursen says the slime is made up of dead cells – an expendable surface that dries out over time. This keeps the mushroom from succumbing to insects and bacteria, allowing them to extend their fruiting season.

On a mushroom walk at Creamer’s Field Saturday, Sept. 10, Lawrence Millman plucked a mushroom from the ground and stuck it to the underside of his hand. Sticky coat. Sometimes, the coating might also protect mushrooms against the cold, according to Millman, a travel writer and fungus enthusiast whom I’ve mentioned before.

This question traces back more than a hundred years – when a scientist named Worthington Smith wrote a letter to the editor in Nature in 1891. The gluten-based coat on a mushroom might help spores stick to new homes, Smith suggested. Surely another force is at work, another scientist named M.C. Cooke responded, shooting down Smith’s suggestion.

Cooke went on to describe a common slender brown mushroom (now known as Panaeolus acuminatus) that grew well into January (I’m assuming in a more temperate locale). This Panaeolus grew stickier as it got colder – a frost adaptation.

Other fungi have antifreeze proteins. This slime might protect against both disease and the elements.

“These antifreezing agents also help prevent the soils from freezing, conferring protection to plants during extreme cold,” according to “Mycelium Running,” a mushroom culturing guidebook.

Being stamped as cold-tolerant comes with heavy implications, enough to drive 19th-century experts to bicker in public forum. Think about it – if a mushroom can overcome cold, then an early frost means nothing. These immobile beings created an insulating shelter by manipulating water.


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