Team:DTU-Denmark/Safety
Safety
Choosing a non-pathogenic chassis
The Aspergillus family consists 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 (1). 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. In addition to this, 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 diseased individual (2). Therefore, we consider A. oryzae as an excellent host for our experiments.
Drylab's unusual experiments
Testing the fungal material in the lab can give rise to various unusual safety concerns. One of them is that we had to be absolutely sure that the resulting GMO material was completely dead after the completion of the experiments, preventing undesired occurrences such as the spread of living fungal spores. As indicated by the literature (3), baking of the products and testing their viability afterward could resolve this issue. Specifically, spores needed to be killed at 70° Celsius(3) during an overnight incubation, which we confirmed experimentally. 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. 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.
There is really not much to say about the safety procedures used every day in the lab at DTU Byg, which have all the big machines used for testing the mechanical properties of the fungi. 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) Microbe wiki. 2018. Aspergillus oryzae.
(2) Barbesgaard P, Heldt-Hansen H, Diderichsen B. 1992. Appl Microbiol Biotechnol 36:569-572.
(3) Jensen H. 1948. Thermal Death Points for Spores and Mycelia of Moulds on Fermented Tobacco. Physiol Plant 1:255-264.