Team:DTU-Denmark/Safety
Choosing a non-pathonenic chassis
The Aspergillus family consist of a few hundred of mold species that prosper in a large number of different climates around the world. They can have various applications ranging from microbial fermentations to medicinal applications. However, it has been reported that some of the strains can cause animal and human diseases. The choice of Aspergillus oryzae as our experimental organism was vastly dependent on its safety features. Briefly, invasive growth or systemic infections by A. oryzae in healthy humans have never been reported. What is more, A. oryzae does not produce aflatoxins or any other cancerogenic metabolites. In spite of its low pathogenic potential A. oryzae may like other harmless microorganisms, grow in human tissues under exceptional circumstances. For example, allergic diseases primarily caused by A. oryzae have been reported in a few cases, but their occurrence is probably dependent on the sensitivity of the deceased individual. Therefore, we consider A. oryzae as an excellent host for our experiments.
Drylab's unusual experiments
When testing the fungal material, an unusual safety concern was that we had to be absolutely sure that the GMO material was completely dead, as to not spread any live spores outside of the laboratory. We did this by baking the product, and testing the viability of any baked spores. We found literature suggesting that the spores were killed at 70° celsius (3), which was confirmed by our experiments.
In addition to this we exposed our fungi to large amounts of gamma radiation (comparable to a dose rate received on Mars). These experiments were performed in a controlled environment at DTU Risø, where the sources were encapsulated in lead, and only raised after the testing room was evacuated. The walls of the testing room were lined with lead, and dosimeters were worn at all times to check the levels of background radiation.
There is really not much to it. We have to be sure to NOT stick our appendages (hands, fingers etc…) into the machine performing the compression tests. It moves very slowly, so it is in principle hard to have any accidents there.
(1) Barbesgaard, P., Heldt-Hansen, H. P., & Diderichsen, B. (1992). On the safety of Aspergillus oryzae: a review. Applied Microbiology and Biotechnology, 36(5), 569-572.
(2) https://microbewiki.kenyon.edu/index.php/Aspergillus_oryzae
(3) 1. Veterinary R. 1948. Thermal Death Points for Spores and Mycelia of Moulds on Fermented Tobacco 1.