Our work is focused on the biology of fungi and different aspects of mycotoxin chemistry. We are exploring biological effects and ecological roles of fungi and mycotoxins in a One Health perspective. Toxins from fungi are widely grouped into toxins from moulds (“mycotoxins”) and toxins from higher fungi (“mushroom poisons”). This is a rather vague differentiation and not based on scientific taxonomy.
Fungi
Mycotoxins
There are many definitions for what a mycotoxin is. Mycotoxins have for example been defined as “natural products from moulds that evoke a toxic response when introduced in low concentrations to vertebrates”. Mycotoxins are products of a fungus’ secondary metabolism, i.e. that part of fungal metabolism that is not essential for cell growth and maintenance of basic cell function. Why fungi produce such substances is not entirely clear, but they may, at least in part, be used for “chemical warfare” and thus provide some advantage to survive in the environment.
Important groups of mycotoxins
Ergot alkaloids | Aflatoxins | Ochratoxins |
---|---|---|
mainly produced by fungi within the Clavicipitaceae | produced by several Aspergillus spp | primarily produced by Aspergillus and Penicillium spp |
cause ergotism | hepatotoxic, strongest natural carcinogens | nephrotoxins, immune suppresive |
Fumonisins | Trichotecenes | Zearalenone |
---|---|---|
mainly producers Fusarium verticilliodes and F. proliferatum | produced by Fusarium spp, four subgroups: type-A – D | produced by Fusarium spp |
hepatotoxic, leukoencephalomalacia (horse) | cytotoxic, inhibit protein- and DNA-synthesis | mycoestrogen |
Mushroom poisons
Mushroom poisoning is commonly caused after consumption of raw or cooked fruit bodies of toxic species. Poisonous mushrooms are often referred to as toadstools from the German word “Todesstuhl” (= death’s stool). Mushroom toxins may be classified into four groups according to their principal biological effect:
protoplasmic poisons | neurotoxins | gastrointestinal irritants | disulfiram-like toxins |
---|---|---|---|
generalised destruction of cells followed by organ failure | profuse sweating, coma, convulsions, hallucinations | nausea, vomiting, abdominal cramps, diarrhoea | producers of coprine, only toxic when alcohol is consumed within approx. 72 h of ingestion |
e.g. false morel (Gyramitra esculenta) | e.g. deadly fibercap (Inocybe erubescens) | e.g. brown rollrim (Paxillus involutus) | e.g. common ink cap (Coprinus atramentarius) |