*3.3. Growth of Mycelium-Based Materials with Coprinus comatus*

In contrast to the first batch, mixtures L and S of the second batch contained different amounts of contamination. All specimens from mixture L were fully contaminated, and only displayed nil to low amounts of *Coprinus comatus* mycelium growth. In addition to the same species contaminating the first batch, materials grown from mixture L of the second batch also contained slime mold. All these specimens were documented and directly discarded to reduce the spread of contaminants to other specimens. In comparison, specimens grown from mixture S only displayed very low amounts of contamination across all specimens and were covered with mycelium. A share of 44% of the panels grown for bending, and 25% of the specimens grown for compression testing, exhibited some contamination. However, the levels of contamination were very low compared to the first batch, and no contamination was removed from the specimens. The difference in contamination levels is likely due to the pasteurization process not being successful for mixture L. The same pasteurization procedure was used for both mixtures, with the only difference being that mixture L was pasteurized before mixture S. In summary, all specimens grown from mixture L had to be thrown away due to the high levels of contamination and lack of *Coprinus comatus* mycelial growth. In contrast, all materials grown from mixture S were covered with mycelium and tested with no contamination removed.
