1. The major mycology branches and their enthusiastic followers
When I ask people about mushrooms they start to smile. Obviously some of them think of pleasure, medicinal benefits, passion, or bad experiences. I personally see them as addictive a virus that once it gets into someone’s blood stream gets trapped inside there for years while the host turns into a mushroom freak: a believer, and a thinker that it said to always carry mushrooms on his brain.
It simply changes your mind, you start to think through the mushroom filter and because of this it also changes your life. It’s a powerful addiction able to lift you higher, the more you discover the more fascinated you get. I can easily observe several categories out there:
The mushroom growing enthusiasts
For example if you drive on a road and see at the margin a bale of straw left to rot by its owner, you’ll suddenly imagine on how a bunch of mushrooms could take over that straw –it would definitely do a great substrate for some oyster mushrooms –this is what your mind will tell you. This is just one example but in reality you’ll feel this at least 10 x stronger with a bunch of mushrooms popping on your head while you cruise around and see various things that would help you grow your own mushrooms.
This is the case with those who want to grow mushrooms for food or for commercial purposes. They are simply fascinated when they see their result after all of that hard work growing and developing into wonderful mushroom fruitbodies. Many believe that growing mushrooms is pretty much like growing a tree of cash, even though this is true there’s lots of work involved.
One thing is clear though, those who are passionate with this feel pleasure and stick with it for a long time, but those focused on making cash only from growing mushrooms are not fascinated nor addicted and therefore they are more likely to give up once they find a better source of cash flow.
The mushroom treasure enthusiasts
Mushroom foraging is their passion and they like to be in nature a lot and they’re pleasure is to find mushroom treasures. Most of these guys are fungivores and know how to cook. They are especially interested in fungi identification and seek to acquire knowledge.
This kind of addiction is rather simple and loads the brain with pleasure when seeing wild mushrooms anywhere, even in a supermarket. Unfortunately, their pleasure depends on the meteorological conditions: no rain –no mushrooms, but guess what?
They need to find their treasures even when there’s no rain around so they find themselves in the woods walking with their heads curled towards the ground. They’re addiction is so powerful because even if they know that there’s no mushrooms around they keep looking to find them –they simply developed a reflex of constant search and because of it they don’t really n-joy the view above their heads.
The mycelium enthusiasts
This type of enthusiasts are simply fascinated with the growth and development of mycelium as a potential for novel things –they could be called mushroom spawn freaks. They really n-joy being lab nerds and play around with fungus mycelium all day long. When they get into it they’re lost for hours and forget to eat or even sleep sometimes.
Their mind is in a constant vibration around mycelium thinking to manipulate that in their favor to get the best out of it in terms of enzymes, extracts, fuel, and other valuable compounds. Their addiction is so bad that even if they’re outside with friends talking and smiling, part of their minds is thinking about fungus –the fungus hyphae colonized their brain and gives birth to pinheads on their head, so don’t be surprised if you talk to them about a random topic and see them suddenly switch to mushrooms.
Mushroom artists
Well, this is a new kind of mushroom addiction and it’s a higher state in which the ones who passed through the previous experiences became enlightened and their brains have special desires for exploring new areas so they can apply what they know into forms, poems, art, furniture, an you name it. It’s the fairy land of innovators willing to push mycelium power to the limit.
Cash doesn’t matter to them much, it’s just a side effect, but what matters most is the creation itself. They are the ones who hold the keys to the doors of mycology understand the mechanisms and have the proper sense to feel and smell the success approaching. They are poly-branched in the field of mycology, focused on various branches of mycology, and therefore they’re able to make connections and sprout new interesting ideas.
There’s much to talk about this and of course this whole topic could be expanded. However, this is for you to understand the power of mushrooms, because once you dive into it you might get forever trapped.
2. The nasty side of mushrooms
Mushroom farming is not only a source of nutritional rich food but also a provider of effective medicinal products. In the last decades, mushroom cultivation has become very popular among people all over the world. 31 billion tons was the number of the world’s total edible and medicinal mushroom registered in 2012. Different cultivating techniques have developed throughout the years and this has contributed to an increase in mushroom production.
Cultivation has evolved from a relatively primitive method to a highly technological industry. The basic principles are the same for all mushrooms, but the practical approaches differ depending on the species. A person who decides to grow mushrooms for the purpose of consumption has to be aware that even though he or she does not skip any step of the grow process, toxic substances may still be present within the resulted frutibodies, and they should not be neglected.
As one starts out in this field, the strategy should be identifying a strain that is compatible with the climate conditions in that specific area, is able to grow on the available substrates, has a quick production and requires a decent cost and infrastructure to sustain harvest consistently.
The presence of toxic substances like heavy metals in soil, air, water and organisms has always been of great concern and considered a threat to human health. They are cytotoxic, carcinogenic and mutagenic. Some of them are toxic even at trace levels. They tend to accumulate in tissues and organs and cause serious harm.
Interest is shown especially in the content of these substances found in edible mushrooms. Although cooking and preservation might decrease the levels it does not make them disappear. Fungi are indicators of heavy metal concentration in the environment. They reflect the level of contamination through different metabolic and morphological characteristics. Exposure to the heavy metal content results in physical, neurological and muscular disorders.
There are several factors that contribute to the accumulation ability like species, heavy metal identity, the substrate’s pH, age of culture mycelia, etc. EFSA (European Food Safety Authority) has listed some safe levels for heavy metal ingestion known as TDI (tolerable daily intake). Nickel, a naturally occurring metal can be found in food and water as a result of industrial contamination.
The TDI is 2.8 µg/kg of body weight. Mercury, a heavy metal of elevated risk is tolerable in 1.3 µg/kg of body weight. Cadmium, another very popular metal is labeled at 2.5 µg/kg of body weight TWI (tolerable weekly intake). Lead is an environmental contaminant whose occurrence is sustained by different human activities. Regulations have decided that the maximum levels present in mushroom should be of 0.30 mg/kg wet weight.
Researchers have found that the content of heavy metals in fruitbodie increases in polluted areas. What’s peculiar about this is that some species of mushroom are not affected by the pollution and the content of heavy metals found in them is significantly lower compared to others. Also, it was discovered that the cap held higher concentration than the stalk in most cases. A study performed on distinct species of mushrooms and conducted by several scientists found out that the highest cadmium concentration was signaled in Agaricus arvensis, 117 mg/kg.
The highest nickel, Pleurotus ostreatus, 145 mg/kg. Concerning the concentration of mercury, an amount of 120 mg/kg was found in only one sporophore of Lycoperdon utriforme. Most species accumulate cadmium, lead and nickel. There are some types of mushrooms that can present two metals in high concentrations: Agaricus bisporus, Lepista nuda (lead and nickel), Marcolepiota procera (lead and mercury), Agaricus sylvicola (cadmium and nickel).
Apart from heavy metals, fungi can also carry insecticides. Sugarcane bagasse is used in mushroom compost production. In order to prevent and combat pests, people use a substance called fipronil. It effectively controls insects but using it might lead to the formation of toxic metabolites. Exposure to insecticides is neurotoxic.
Sun mushrooms have the tendency to accumulate fipronil from the compost if available and this poses threat to human consumption. Studies have revealed that the presence of fipronil in the compost did not lead to accumulation in fruit bodies. On the other hand, when added to the soil casing layer, the results showed bioaccumulation in the mushrooms. One interesting fact is that fipronil adsorption is higher in soils rich in organic matter.
Mushrooms are also vulnerable to radiocesium contamination occurring from a radioactive fallout. Boletus badius is commonly known to hold affinity for contamination with radioactive substances. After the Chernobyl nuclear incident, researchers have gathered samples of mushrooms from different parts of Poland and analyzed them for nuclear traces. The abundance of radiocesium in mushroom can be attributed to three factors: soil contamination, the specific uptake of various species and mushroom requirements. The radioactive compounds are adsorbed and deposited on the top organic layer of the soil. Some fungi with simplistic mycelia can accumulate these elements readily and in considerable amounts.
It is highly important to take into consideration every minor aspect when deciding to grow mushrooms. Growing them organically, even though it might imply more funds, tests and regulations, has more benefits on the long run but even with this on we won’t be absolutely sure that the mushrooms that we eat are clean.
An article by Malina Puia & Dr T
References
www.efsa.europa.eu
“Organic Mushroom Farming and Mycoremediation: Simple to Advanced and Experimental Techniques for Indoor and Outdoor Cultivation” book by Tradd Cotter
Chang, S. P. Wasser, “The Cultivation and Environmental Impact of Mushrooms”, 2017
Mogildea Daniela, “Bioaccumulation of toxic heavy metals in mushrooms -A review”, 2016
A. Carvalho et al., “Bioaccumulation of insecticide in Agaricussubrufescens”, 2014
Falandyz, et al., “Evaluation of the radioactive contamination in fungi genusBoletus in the region of Europe and Yunnan Province in China”, 2015
Das, “Heavy metals biosorption by mushrooms”, 2005
D. Raj, et al., “Mushrooms in the remediation of heavy metals from soil”
Dulay, M. De Castro, “Cadmium and chromium tolerance and mycoremedication ability of tiger sawgill mushroom, Lentinus tigrinus”, 2016.