Evaluation of different wood by-products for sustainable building biomaterial production using fungal mycelium

As human population increases, the demand for new innovative, sustainable, and low impact construction materials also grows. Mycelium-based composites have shown to be an excellent alternative for traditional products ranging from low-density objects to semi-structural applications. They also present the advantage of using the waste streams from other productive processes as feedstock, enabling the upcycling of materials that can help us transition into a circular economy. In this study three different experiments were carried out: first the selection of the fastest growing fungal strains and the process' temperature; secondly, three different grain spawn media were evaluated for inoculum production and the last one was a qualitative screening of mycelium growth in different wood by-products. G. lucidum, T. versicolor and P. ostreatus grown at 25 °C were chosen due to their fast-developing rate and mycelium density in comparison to P. eryngii and F. pinicola. For grain spawn production of these strains, a 1:1 mix of wheat and millet was found to be the best option to accelerate the mycelium growth rather than using the grains separately. Different 9x12x4 cm samples were produced using a variety of wood by-product substrates and the shortest production time and more visibly homogeneous material was obtained when growing G. lucidum on beechwood. However, other preliminary test demonstrated the great potential of mixed substrates for production times reduction. The next steps for this research include substrate optimization using mixed wood substrates and further characterization of the biocomposites including thermal conductivity and humidity resistance tests.