Truffle, Truffle, who’s got the Truffle? Tuber spp. are ectomycorrhizal ascomycetes that produce ascocarps known as truffles. The origin of the word truffle appears to be the Latin term tuber, meaning “lump”, which became tufer- and gave rise to the various European terms: French truffe, Spanish trufa, German Trüffel, Dutch truffel and Croatian tartuf. These ‘lumps’ fetch quite a high price. In 2001, Tuber magnatum truffles sold for between US$1,000 and $2,200 per pound on average! However, the record price paid for a single white truffle was set in December 2007, when Macau casino owner Stanley Ho paid US$330,000 (£165,000) for a specimen weighing 3.3 lbs!

So what makes these mushrooms worth so much money? Truffles are an ecto-mycorrhizal mushroom that grows underground. Ecto-mycorrhizal fungi are notoriously difficult to cultivate, as they must be in association with a specific plant/tree to survive. But to top it all off, they are very difficult to find as they are always underground. Many truffle hunters must use dogs or pigs to sniff them out.

However, truffles can be cultivated. As early as 1808, there were successful attempts to cultivate truffles, known in French as trufficulture. People had long observed that truffles were growing among the roots of certain trees, and in 1808, Joseph Talon, from Apt (département of Vaucluse) in southern France, had the idea to sow some acorns collected at the foot of oak trees known to host truffles in their root system. The experiment was successful: years later, truffles were found in the soil around the newly grown oak trees. In 1847, Auguste Rousseau of Carpentras (in Vaucluse) planted 7 hectares (17 acres) of oak trees (again from acorns found on the soil around truffle-producing oak trees), and he subsequently obtained large harvests of truffles. He received a prize at the 1855 World’s Fair in Paris.

These successful attempts were met with enthusiasm in southern France, which possessed the sweet limestone soils and dry hot weather that truffles need to grow. In the late 19th century, an epidemic of phylloxera destroyed many of the vineyards in southern France. Another epidemic destroyed most of the silkworms in there, too, making the fields of mulberry trees useless. Thus, large tracts of land were set free for the cultivation of truffles. Thousands of truffle-producing trees were planted, and production reached peaks of hundreds of tonnes at the end of the 19th century. In 1890 there were 750 square kilometres (190,000 acres) of truffle-producing trees. In the 20th century however, with the growing industrialization of France and the subsequent rural exodus, many of these truffle fields (champs truffiers or truffières) returned to wilderness.

The First World War also dealt a serious blow to the French countryside, killing 20% or more of the male working force. As a consequence of these events, newly acquired techniques of trufficulture were lost. Also, between the two world wars, the truffle fields planted in the 19th century stopped being productive. (The average life cycle of a truffle-producing tree is 30 years.) Consequently, after 1945 the production of truffles plummeted, and the prices have risen dramatically. In 1900, truffles were used by most people, and on many occasions. Today, they are a rare delicacy reserved for the rich, or used on very special occasions. In the last 30 years, new attempts for mass production of truffles have been started. Eighty percent of the truffles now produced in France come from specially planted truffle-fields. Nonetheless, production has yet to recover its 1900s peaks. Local farmers are opposed to a return of mass production, which would decrease the price of truffles. There are now truffle-growing areas in the United States, Spain, Sweden, New Zealand, Australia, Chile and the UK.

In 1999, the first Australian truffles were harvested in Tasmania, the result of eight years of work. Trees were inoculated with the truffle fungus in the hope of creating a local truffle industry. Their success and the value of the resulting truffles has encouraged a small industry to develop. A Western Australian venture, The Wine and Truffle Co, had its first harvest in 2004, and in 2005 they unearthed a 1 kg truffle. In 2008, an estimated 600 kilograms (1,300 lb) of truffles were removed from the rich ground of Manjimup. Each year The Wine and Truffle Co. has expanded their production, moving into the colder regions of Victoria and New South Wales.

In June 2010, Tasmanian growers Michael and Gwynneth Williams harvested Australia’s largest truffle from their property at Myrtle Bank, near Launceston. It weighed in at 2 lb 6.2 oz. Ms Williams told ABC Radio in Australia that it is valued at approximately AUS$1,500 per kilo.

Next week in Part 2, we will discuss the lab techniques needed to grow Tuber spp. in vitro. I hope you all had a very Happy New Year and will check back with us soon.

(adapted from the Truffle- Wikipedia article)

While walking through Whole Foods in Boulder, I noticed that they had a wonderful selection of mushrooms for the Thanksgiving season. Bluefoots from France, Maitake from Oregon, Oysters from Colorado, King Trumpets, Black Poplar mushrooms, Shimeji mushrooms, Shiitake mushrooms, Enoki mushrooms, but what got my attention, was the huge bowl full of Chanterelles. The wonderful orange and gold color and smell gets me every time. I had to pick out a pound to bring home for the holidays. But all this got me thinking about growing Chanterelles, so I did a little research and found out some interesting information. First let me explain a little bit about mycorrhizal fungi and give a little background on the genus Cantharellus before we get too far ahead of ourselves. The word ‘mycorrhizal’ comes from Greek; ‘myco’ (fungus) and ‘rhizal’ (root). Mycorrhizal fungi have adapted a clever way to survive, by associating themselves with a specific vascular plant or plants, so as to uptake various carbohydrates (starches and sugars) that aid in the fungi’s development. The fungi achieve this by encasing/injecting mycelia into the roots of the plant, while not harming the plant’s growth. In fact, through this symbiotic relationship, the plant receives various minerals and nutrients (some of which are generally unavailable in some climates, locked up in the rock/soil), a greater ability to absorb water, resistance to parasitic fungi (i.e. blight) and soil-borne pathogens, as well as resistance to many toxic heavy metals. As you can see, this situation is very advantageous for both the plants and the fungi. So beneficial in fact, that it is believed that this is the most widespread form of symbiotic association found in the entire plant kingdom and according to dated fossils, is a relationship that is at minimum 400 million years old (for more information, and something cool to check out, Google ‘The Rhynie chert’). That is a long time to live together. Can you imagine the connection plants and fungi must have? Do they ever get sick of each other? Are fungi and plants emotional beings? These are all questions for a different blog post. Let’s get back to the topic at hand… Chanterelles! Chanterelles are a part of the genus Cantharellus which abounds with many very beautiful and very delicious fungi, all which happen to be… you guessed it, mycorrhizal fungi. For a cultivator of mushrooms, growing mycorrhizal mushrooms is a very daunting task. As I just explained above, you need specific plants to partner up with specific fungi. Did you ever see that MTV dating show, ‘Next’? There are multiple ‘dates/contestants’ picked for one person to go on a date with. This person must choose which of the contestants was what they were looking for in a mate. The mushroom cultivator is like the matchmaker in this situation. The only problem is that just like dating, each species of fungi needs different things than others for the relationship to work. Just like in the show, some relationships are more compatible than others. But beyond just finding the correct partner plant to grow with, the cultivation of Chanterelle mycelium is more difficult still. As you probably already know, mycelium is the organism of the fungi that produces the fruiting body/mushroom. To grow the mycelium away from its host plant’s roots means the cultivator must have a medium to grow it on that contains all of the essential nutrients that the host plant and environment are feeding to the fungi. While searching for information on this subject, I found a very interesting patent invented by Eric Darnell (Chanterelle Mycelium US Patent #6173525) that explains a process of selecting a viable strain of Cantharellus cibarius, the golden chanterelle. If you would like to read it in its entirety, Click Here. In this process, he uses a media called Modified Fries Medium (a medium generally used in test tube plant culture) or Murashige and Skoog Medium with several of his own additions including activated charcoal. He uses these mediums because chanterelle mycelium has very slow/non-existent growth on the standard mediums, Malt Extract Agar (MEA) and Potato Dextrose Yeast Agar (PDYA). They just don’t contain the right types of nutrients for these mycorrhizal fungi. He then also adds several antibiotics that keep the co-inhabiting bacteria and fungi sequestered. These live in symbiosis with the fungi in the wild, but would proliferate in the Petri dish and slow the growth of the chanterelle mycelium. After 17-53 days, chanterelle mycelium begins to grow inside and through the agar. He is then able to transfer pieces of the mycelium to new MFM Petri dishes, this time without antibiotics as they are no longer needed. The co-inhabiting fungi and bacteria are left behind in the previous Petri dish. They then performed genetic sequencing on the mycelium they had isolated just to make sure that it was indeed Cantharellus cibarius mycelium they were growing. Sure enough, they had come up with a way to grow chanterelles in vitro. Cool and exciting stuff! But to top it off, in 1997, E. Darnell and F. Camacho produced the first ever successfully cultivated Cantharellus cibarius in a potted 16-month old Pinus sylvestris with a mycelium grown for only one year in culture. (In fact the photograph of the chanterelle at the top of the post is the first ever cultivated chanterelle) Hopefully with time, Eric Darnell can make this idea a commercially viable concept. Recently, Darnell started a Swedish company called Cantharellus AB to do just that, but has had mixed success. Many different animals and insects love his concept for chanterelle orchards, and have been giving him problems consuming and disturbing his mushroom harvest. They have planted thousands of inoculated trees that should start producing in 10 years. So far, the study of mycorrhizal mushrooms and their cultivation is still in its infancy, but is rewarding for those who have the patience to study these amazing and delicious fungi. For more information visit Eric Darnell’s Cantharellus Site or Chanterelle Mycelium US Patent. Another interesting pdf I found at David Arora’s site that he helped write is called A New, Commercially Valuable Chanterelle Species, Cantharellus californicus sp. You should check it out! Well, that’s all for now. Have a good and happy Thanksgiving!
References below:
Danell E & Camacho F (1997) Successful cultivation of the golden chanterelle. Nature, 385: 303. In the same issue of Nature on pages 299-300, Professor Roy Watling presents “The business of fructification”
Oh and all the pictures from this post were from Eric Darnell’s site with link above.

James and I have been spending the past 3 months amassing mushroom species in pure culture and putting them under cold storage. You might be thinking, “what the heck is he talking about?”. To explain a little more clearly, we are ‘cloning’ wild mushrooms. This process is done by extracting flesh or spores from mushrooms that we have collected in the wild, and growing them in petri dish or test tube on different types of ‘media’. This media gives them nutrients specific to the species of fungi we are trying to grow. Now, when we talk about growing mushrooms, you first must isolate the part of the fungus that produces the mushrooms. Mycelium is a network of hyphae, or chains of cells, that are able to uptake water and various nutrients, as well as excrete digestive enzymes to digest it’s food, which in turn produces the mushroom. The mushroom is actually the fruiting body or sexual reproductive organ of the mycelium that produces spores to grow more mycelial networks. Under cold storage (i.e. 38 degrees F) the mushroom mycelium’s growth slows to a crawl. This allows the cultivator to store the mycelium until it is ready to use. To see a complete list of the different species we have go to The Amateur Mycology Culture Library page. We update it regularly.