No December Meeting

Potluck party instead, note changed date and location

When: Tuesday, December 11.
Time: 6 to 9:30 PM
Where:
Nan Couts Cottage
MacArthur Park
5054 Memorial Drive
La Mesa, CA
(Corner of University Avenue & Memorial Drive)

Park Information

Directions and map

Join members of the SDMS for our annual potluck party.  Dig out your favorite recipes with wild or cultivated mushrooms or other good things.  Bring it ready to serve, there is no cooking allowed at the facility.  Bring any required serving implements and dishes, do not assume that anything is available at the facility.

Soft drinks and coffee will be provided.  If you want something stronger, please bring your own.

Festivities will include a "white elephant" gift exchange.  You may go home with the Harley Barnhart memorial spoonholder.

Now is your chance to get rid of that awful gift that has been gathering dust in the closet ever since someone completely unfamiliar with your taste in household objects gave it to you years ago.  Wrap it up and bring it to the party for the "Most Awful" gift exchange. Trading will be allowed, or possibly encouraged, just in case your white elephant turns out to be the apple of someone's eye. De gustibus non disputandum!

No RSVP is required, and nobody is organizing the food.  It always seems to work out well enough, so bring whatever you like.

How Amanitas Make Toxins

Heather Hallen spent eight years looking for poison in all the wrong places.

Alpha-amanitin is the poison of the death cap mushroom, Amanita phalloides. The Michigan State University plant biology research associate was looking for a big gene that makes a big enzyme that produces alpha-amanitin, since that’s how other fungi produce similar compounds. But after years of defeat, she and her team called in the big guns – new technology that sequences DNA about as fast as a death cap mushroom can kill.

The results: The discovery of remarkably small genes that produce the toxin – a unique pathway previously unknown in fungi.

The discovery is reported in today’s Proceedings of the National Academy of Sciences. It is work that not only solves a mystery of how some mushrooms make the toxin – but also sheds light on the underlying biochemical machinery. It might be possible one day to harness the mushroom genes to make novel chemicals that would be useful as new drugs.

“We think we have a factory that spits out lots of little sequences to make chemicals in Amanita mushrooms,” said Jonathan Walton, MSU plant biology professor who leads Hallen’s team. “Our work indicates that these mushrooms have evolved a mechanism to make dozens or even hundreds of new, previously unknown chemicals, besides the toxins that we know about.” Of the thousands of species of mushrooms, only about 30 produce alpha-amanitin. Most of them look much like their edible cousins.

Alpha-amanitin kills people by inhibiting an enzyme necessary for expression of most genes. Without the ability to synthesize new proteins, cells quickly grind to a halt. The intestinal tract and the liver are the hardest hit as they come into first contact with the toxin. By the time symptoms show up, a liver transplant is often the only hope.

Walton’s lab works to understand the biochemical pathways by which natural products are synthesized in fungi.  To find the elusive gene for alpha-amanitin, they used what they term “brute force” – a new machine at MSU that can sequence immense quantities of DNA quickly. What they found was a gene that encodes the toxin directly – with no need to first synthesize an enzyme that in turn would make the toxin.

“The RNA goes in, and out comes the backbone of the toxin,” Hallen said. After its initial synthesis, the toxin is then modified in several ways by the mushroom to make it exceptionally poisonous.

Walton said the discovery poses some interesting evolutionary questions. For example, why do only some mushrooms produce this toxin? And how did a handful of other, unrelated mushrooms evolve the same trait? Finding the genes points to how the trait could appear in one mushroom, but not how it evolved in mushrooms that aren’t related to Amanita.

Hallen and Walton also see the doors opening to a diagnostic test that could use DNA to determine if a mushroom is toxic or not. Identifying a mushroom by shape and color alone is often impossible if the mushroom has been cooked or partially digested, yet rapid and accurate identification in an emergency room situation is critical.

News Release  Wednesday, November 14, 2007

Aquatic Mushrooms

Mail Tribune (Southern Oregon)

SHADY COVE — Hydrologist Robert Coffan knew he was looking at something very unusual in the knee-deep summer waters of the upper Rogue River.

Here were gilled mushrooms, swaying in the main current of the clear, cold river in early July through late September.

"But since gilled mushrooms DO NOT live and grow underwater, I was real nervous" about approaching a mycological expert, admitted the adjunct professor at Southern Oregon University.

Indeed, Darlene Southworth, a retired SOU biology professor, was plenty skeptical when he broached the subject. Although she was impressed by underwater photographs taken by Coffan, she wanted to see the evidence firsthand.

Not only did she witness the mushrooms found by Coffan, but she discovered others during an August visit to a stretch of the north fork of the river within a few miles of Woodruff Bridge in the Rogue River-Siskiyou National Forest.

"There are no known gilled mushrooms living underwater," Southworth explained. "And this is not a slime mold or anything like that. These are regular gilled mushrooms.

"We believe this is a new species," she concluded of the mushrooms that are typically about 10 centimeters tall with caps that are about 2 centimeters wide.

Dubbed Psathyrella aquatic, the mushroom is being introduced to the broader scientific community in a 14-page paper submitted Nov. 9 to the science journal Mycologia. The paper was written by Coffan in collaboration with Southworth and Jonathan Frank, a laboratory technician at SOU.

Coffan credits Southworth, who now conducts research under a National Science Foundation grant at the university, for focusing on mycorrhizal fungi, and Frank for the paper and much of the research in determining the mushroom's uniqueness.

Up at Oregon State University, Matt Trappe, a doctoral candidate in forest mycology, says Coffan has found a unique mushroom. He and his father, Jim Trappe, a retired U.S. Forest Service mycologist who now teaches in OSU's botany and plant pathology department, were consulted on the find.

"As far as we've determined, this is a first in Oregon as well as a first in the world," Matt Trappe said of gilled mushrooms living in water. "We're not aware of anything at all like this in mycology where the reproductive mushroom structure appears to be perennially underwater.

"If this evolved in Oregon, what are the odds it can be found in streams and rivers around the world?" he asked. "This raises all kinds of questions about spore disbursement and evolution."

There are more questions than answers at this point, acknowledged Coffan, who originally discovered the water-dwelling gilled mushrooms in summer 2005. None of the mushrooms were found in slack water, he noted.

A DNA analysis at SOU's Bio Tech Center and a cross-check of references and experts, including mycologists at the University of Minnesota, determined the mushrooms belonged to the genus Psathyrella, Southworth said. Samples were sent to OSU and to San Francisco State University.

There are about 600 known species of Psathyrella, all terrestrial, she said.

"How do we identify them? We look at the morphology — the form, the shape and the DNA," she said.

It has a small bell-shaped cap, a thin stipe (stem) and gills underneath, she said. They examined the cells in the cap and made a spore print.

Researchers have ruled out the possibility the mushrooms were growing along the banks and were merely submerged by rising waters brought on by snowmelt.

The mushrooms were found in the spring-fed "base" flow of the river, Coffan said, noting that flow is consistent and keeps the mushrooms submerged.

The mushrooms tend to grow on submerged wood but can also be found growing in the gravel, Southworth said.

"These are growing in the same place for three months, " she said, adding they have been found as late as Sept. 21.

Although there are some known freshwater aquatic fungi, this is the only known gilled mushroom that grows underwater, she reiterated.

"We noticed there is a gas bubble underwater," she said. "When we pulled the mushroom out, we could hold it up for some seconds before the spore burst. But they would not be uniformly distributed. They would stick to the cap, to the stipe, to Jonathan's fingers."

They don't know what the gas is, she noted.  They are also intrigued by its three-month fruiting season.  "That's way long for mushrooms," she observed.

As for their edibility, Southworth figures the waterborne mushrooms are too small to warrant collecting for food.  However, several of the terrestrial Psathyrella are edible, although most have never been tested as a food source, according to her research.  "There is no reason it would go toxic," she observed of a member of the genus growing in water.

Meanwhile, Coffan, Southworth and Frank plan to return to the area to conduct further research to try to determine the extent of the mushroom's habitat. They also want to check out other streams in the region for evidence of the mushrooms.

"But it will be next summer before that is feasible," she said. "Right now we can describe this one river: It's aerated, cold, clear, steady flow. But we want to find out how the spores are dispersed."

"And we want to find out how unique the habitat is," Coffan said. "We have a whole new area to look for mushrooms now. It's mind-boggling."

What’s Cooking

Fungi as Food

Recipes by Patrick Hamilton

 

Many thanks to visiting chef and lecturer Patrick Hamilton for an excellent cooking demonstration.

 

Golden Chanterelles in Beurre Fondue

1 pound chanterelles, pulled apart
2 Oz water
6 Oz butter, unsalted, cut in slices
sea salt
freshly ground black pepper
1 tsp tarragon, minced

1. Boil the water in a saucepan and then whisk in the butter.

2. Add the pulled apart chanterelles and a sprinkle of salt and cook over medium high for 8 minutes or so - until the water has evaporated.

3. Continue to cook until all the water vapor stops sizzling, stirring to disallow burning.  Lower the heat a little and sauté the mushrooms for another 5 minutes or so - until they begin to crisp on their torn edges.  Drain off the butter and place the mushrooms in a warmed bowl.  Set the butter aside for another use.

4. Toss the mushrooms with the tarragon and then adjust the seasonings.

You may add heated, reduced, fruit juice to the dish while tossing in the tarragon.  Apricot, mango, or peach would work well.  For an extra arterial destruction heavy cream can be added then too.

Serve on simple toasts.

Black Chanterelle Crostini

1/2 cup dried black chanterelles
1 large shallot, chopped
1 tbs unsalted butter
2 tbs heavy cream, scalded
1 tbs dry-roasted hazelnuts, pulverized
salt and pepper

1. After rehydrating the blacks in hot water (and saving the liquid) squeeze them dry and sauté with the shallots in the butter for 5 minutes.  Add salt and pepper.  Add the strained hydrating water in batches and cook au sec (until dry).  Remove from heat to cool.

2. In a food processor put the blacks and add the scalded cream and the hazelnuts.  Make into a spreadable mix.

3. Reheat the mixture, maybe add some more scalded cream, adjust the seasonings, and heat thoroughly.  Remove from heat.

4. Spread on crostini (toasted baguette slices)

Herbs may be added to this recipe.  Brandy or wine too.

Note: If possible, use the butter mixture left over from the golden chanterelle in buerre fondue recipe.

Raw Porcini Salad

1 pound porcini mushrooms (buttons best), sliced very thin
2 tbs flat parsley, chopped finely
1 lemon (Meyer preferred)
4 tbs extra virgin olive oil
grey sea salt
fresh black pepper

Slice the cleaned mushrooms very thinly (a mandoline is useful here).  Place the slices in a work bowl, add the parsley, squeeze the lemon over, add the oil, and season to taste.  Gently mix with your hands until the salad is evenly dressed.  Set aside for 15 minutes to allow the flavors to blend.  Adjust the seasonings and dressing, and serve with good crackers or bread.

Editors Note:

We enjoyed the first two recipes at our October meeting.  As a bonus, we had sautéed fresh porcini slices, and also sautéed chunks of a large specimen of Hericium erinaceus that Dennis brought in from the wild.

Thanks to members, there were a variety of other appetizers, with and without mushrooms, so we were all well-fed.

SDMS Information