Ari Huttunen asked:
Hello Naked Scientists!
I have a question(?) concerning both bacteria and fungi. How have some fungi evolved to produce substances that are hallucinogenic like psilocybin? What's the benefit and cost of producing such chemicals? What is known about the group of genes that produce this ability? And are there any such substances produced by bacteria?
Thanks for a great show!
We put this to Professor Mike Cole from Anglia Ruskin University...
Mike - The reason that many fungi produce what are called secondary metabolites is as a defence reaction to their environment. For example, they might prevent attack by animals, plants, other fungi, or in fact, bacteria. They're called secondary metabolites because they're not essential for life in the same way that vitamins, sugars and amino acids are, but they do confer some advantage on, in this case, the fungus that produces them.
The cost includes producing precursor chemicals, supplying the energy compounds, supplying the reducing power. Whilst as forensic scientists we understand a lot about the genetics for the identification of these organisms, there is nothing known about the genetics of how these compounds are produced although we do understand the biochemical pathway in terms of the starting materials and the end product.
There are a host of other compounds that are produced by fungi, plants and bacteria. Perhaps one of the most famous of these are the ergotamine alkaloids which are used postoperatively, but also are hallucinogenic. And also, compounds produced by fungus called claviceps which supplies the precursor chemical for our friend, LSD.
Q. Why do fungi make hallucinogens?
The hallunicogens most commonly associated with fungi are psilocybin/psilocin (tryptamine alkaloids -related to serotonin etc) present in the mushroom (basidiocarp), notably of Psilocybe/Panaeolus spp.
Sorry, better to mention that I posted this question of the week. ;) I'd really like to have some discussion about how common these chemicals are. But mainly of course why fungi do bother to make hallucinogens and how they produced them. Addu, Wed, 31st Oct 2012
Keep in mind that some mushrooms also produce deadly toxins.
There is another concoction of hallucinogens (though not fungi related) made from a brew called Ayahuasca as used by Amazonian tribes. The Banisteriopsis caapi vine contains a monoamine oxidase inhibitor (MAOI) and is mixed with the leaves of dimethyltryptamine (DMT)-containing species of shrubs from the genus Psychotria.
the blue stuff is a known slug killer azrael, Mon, 17th Dec 2012