Results

In the first experiment, the species were seeded at 3 different concentrations of MEA (47,5 g, 50 g and 52,5), PDA (19,5 g, 39 g and 58,5 g) and YPD. Thereafter, growth pictures were taken every 24 hours and the size of the fungal colonies was compared. In addition, different growth conditions (temperature and light) were tested for each of the species. S. commune was incubated 30ºC at light and 27ºC at light, P. ostreatus at 28ºC at dark and 25ºC at light, and A. oryzae at 28ºC at dark and 30ºC at dark.

In addition, we also investigated the growth of a mutated S. commune strain ,ΔSC3.

S. commune, P. ostreatus and A. oryzae grew at a similar rate on all media. However, the mutant strain of S. commune, Δsc3, was able to grow only at PDA 39 g (Figure 2).

This preliminary experiment indicated several species were interesting for our research, as they were able to grow in common media, producing mycelium that could form fungal bricks possibly of use for making fungal materials. After incubation at the following conditions: S. commune at 30ºC at light, P. ostreatus at 28ºC at dark and A. oryzae at 28 ºC at dark, only A. oryzae showed sporulation despite a similar growing speed. As the protoplastation and transformation protocol available to us relied on spores to produce the protoplasts A. oryzae seemed like the best choice of species to continue work on for the genetic engineering part. Furthermore, comparing the bricks it quickly became clear that A. oryzae produced the most coherent bricks (Figure 3), with the other species producing extremely brittle materials. This might be a feature of the substrates chosen for growth, as they were chosen based on species’ preference in terms of growth rate, so for A. oryzae it was rice and for P. ostreatus and S. commune it was saw dust. Addition of coffee grounds did nothing for the texture of the bricks but a mixture of rice and sawdust made the A. oryzae bricks harder. As shown in Table 1, once again it seemed that A. oryzae was the best choice for further work.

In addition to being the only one to sporulate and to form coherent bricks (Figure 4), A. oryzae is a well-studied species that is used in fermentation processes and has been engineered previously. Therefore, we decided to focus the project on forming bricks and doing genetic engineering of genes of interest on A. oryzae.

Eventually, radiation tests were performed on A. oryzae and Ganoderma lucidum (Figure 5). The irradiated samples were kept at a temperature of 20 degrees celsius, controls were prepared and set to grow at the same temperature. The irradiated samples got a combined dose of 63.85 mSv from 28.09.2018, 13.10 to 01.10.2018, 10.45. The irradiated samples had growth radii which were on average twice as large as the controls (Figure 6,7). These results are thought to be spurious, and the most likely candidate is that the sample room was kept at a higher temperature than 20 degrees. The primary result is thus that the fungi were able to grow, but it is unknown if the increased amount of radiation caused an increase in mutations.