Small Things Considered

Let Them Eat Mushrooms

The fifth, and final installment, celebrating the Week of the Fungi on STC. Bon appetit!

by Elio

People who venture into forests in search of mushrooms have insects to contend with. I don't mean mosquitoes, wasps, and bees. I mean bugs that enjoy eating mushrooms at least as much as some of us do. Mushroom hunting is a chancy enterprise at best. But as if that weren't enough, sometimes we come upon a fine specimen of a delectable species, only to find it rendered inedible by insects who got there first. Often we find them riddled with tunnels made by the larvae of fungus gnats that had deposited their eggs in the mushrooms. Some mushroom hunters call these mushrooms “wormy” and joke about their extra protein content. Some joke!

A Pleurotus sp. (oyster mushroom) 10 cm across was placed 1 m
from a colony of E. procera. It didn't take long…

If you watch nature shows on TV, you will know that insects and fungi have numerous, very close connections. Likewise, if you have been reading this blog, you might recall when we brought this up ourselves. But here we're talking about a particular sort of interaction: mycogastronomy.

The Mush in Mushrooms

The fourth of five installments celebrating the Week of the Fungi on STC.

by Elio

You probably think that ultimately all mushrooms turn into mush. Well, yes, indeed they do, but some do it with alacrity. A group of mushrooms called Inky Caps have a way of getting rid of unwanted tissue in their cap by dissolving it. Some of these mushrooms are prized edibles, but unless you pick them when very fresh, your pot will contain only the unappetizing product of the hydrolysis of their tissues. This is a story that mushroom aficionados learn early on their path to wisdom.

Should you want to feast your eyes on a movie of this process, click here. This is yet another of the spectacular movies at the Cornell Mushroom Blog. There you will also find a lovely description by graduate student Jonathan Landsman of the somewhat less than lovely-sounding process of self-digestion.

Deadly Pretzels

Mid-week...the third of five installments celebrating the Week of the Fungi on STC.

by Elio

A bouquet of poisonous mushrooms. Number 3 is
Amanita phalloides. From McIlvaine, C. 1900. One
Thousand American Fungi. The Bowen-Merrill Com-
pany, Indianapolis.

Nasty stuff, those toxins responsible for the toxicity of deadly poisonous Amanita mushrooms. They are pretzel-shaped, bicyclic octa- and heptapeptides known as amatoxins and phallotoxins. One of them, α-amanitin, is familiar to many as a handy reagent for inhibiting RNA polymerase II in the lab. Another one, phalloidin, binds to actin and inhibits its depolymerization. Made fluorescent, it's a convenient way to stain for actin. Phallotoxins are not effective by mouth because they are poorly absorbed. Amanitins are responsible for most of the cases of serious mushroom poisoning, including most fatalities. Incidentally, these are not absorbed all that fast either. Symptoms don't usually become apparent for 12-24 hours after ingestion so if you get sick soon after eating a wild mushroom, it wasn't a deadly Amanita and you'll likely be OK by the next day. Those stories about keeling over right after a great mushroom meal are fictions.

Fiddling with Fungi

This is the second of five installments celebrating the Week of the Fungi on STC.

by Elio

Antonio Stradivari by Edgar Bundy, 1893

Next time you hear a dazzling violinist play on an exceptional instrument, think fungi. (Yes, I can hear it: Here he goes again, playing his old refrain: fungi, fungi…) The reason is that fungi may help us to produce instruments that, at long last, may be comparable to those made by Stradivari and others in the Northern Italian city of Cremona in the early seventeen hundreds. Just how good are Strads? George Eliot said (I paraphrase): God could not make a Stradivarius without Stradivari. Click here for a discussion and snippets of music played on Strads. The reason for their exceptional quality has long been sought. Notions abound.

But Is It Good to Eat?

This is the Week of the Fungi on STC, a sporadic undertaking. It is our way to hail the start of the mushroom collecting season, which in most temperate regions is in the fall.

by Elio

Entoloma rhodopolius from Japan. This
species is also found in North America
and Europe where it seldom causes
poisonings. Source: Chiba Museum

If you are into wild mushrooming, the question you'll be asked most often by someone holding a specimen is: Is it good to eat? I sometimes answer with a dyspeptic: Before I tell you, would you recognize it if you saw it again? But now I have a more friendly answer: Go ahead, cook the mushroom, then do real-time PCR. Japanese researchers (from 7 different labs) recently reported that this works very well, at least for telling four poisonous species apart from 27 edible ones. The PCR primers they used were designed for the rDNA ITS (Internal Transcribed Spacer) regions of the poisonous species—a region often used in fungal and other work. The poisonous mushrooms gave a clear signal, the edible ones did not.

Talmudic Question #37

by Rob Edwards

What's the lowest temperature at which microbes can grow? Clearly it is below 0°C and above − 273°C, so we have a range. See a review on the topic.

Likewise, what's the hottest temperature for growth?

A Timely Article on the Anthrax Story

An opinion piece by Wendy Orent on bioterrorism that we found particularly illuminating was published on August 13, 2008, in the Los Angeles Times.

Fine Reading: E. coli Goes Green

by Tom Bernhardt

Waste not, want not, as the old saying goes. Bacteria have apparently heeded this advice for some time, and this is no doubt one reason why they are such successful organisms. Perhaps we humans should take notes.