Mycotoxins and assessment of environmental risks in laboratory conditions in The Netherlands
Working with genetically modified organisms (GMOs) in the laboratory always requires a certain level of containment. Main issue is to prevent spreading of GMOs to the environment. In addition, the occupational health of the personnel working with GMOs in the laboratory must be secured. In case the GMO is a fungus, evaluation with respect to (1) pathogenicity of the fungus towards humans, animals or plants is required as well as its (2) ability to produce mycotoxins.
The evaluation starts with the adequate identification of the fungus at strain level. This allows a reliable assessment of pathogenicity and mycotoxin producing capacities. Up to recent, identification of fungal strains was mainly based on morphological characteristics which, in many cases, has proven to be insufficient for identification at the species level, let alone at strain level. However, DNA based methods currently enables unambiguous identification of the fungus. Nevertheless, when assessing (older) literature for pathogenicity or mycotoxin production, awareness of possible misidentification must be considered.
In addition, mycotoxin production of the fungal strain needs to be assessed. Over 300 mycotoxins are known but only a few have been evaluated for toxicity for humans and animals. The toxic effects of mycotoxins depend on animal species and on concentrations ingested. Since mycotoxins are often secreted into food and raw materials, EU regulations have been set for mycotoxins in food and feed commodities.
Mycotoxin production by a fungus depends on genetic make-up and growth conditions (both under field or laboratory conditions). The recent notion that many genes are involved in mycotoxin production occur in gene clusters opened the possibility of unambiguous identification of the ability and inability of a fungus to produce certain mycotoxin. Currently, these gene clusters have been recognized for most common mycotoxins.
Aspects to substantiate risk assessment on potentially mycotoxin producing fungi should include fungal taxonomy, toxin production, and relevant genetic make-up and growth conditions of these fungi in laboratory situations.