Development of a circular sustainable culturing process for natural leather-like materials based on fungal mycelium

Samenvatting

This report summarises the research performed to see if the current production system for mycelium as a feedstock for production of a leather-alternative can be optimised. In the current production system, a commercially available substrate is used, on which aerial mycelium of Ganoderma sessile is grown. Several other mushroom species produced mats of aerial mycelium, but none of these strains paralleled the yields obtained with the current production strain. Next to attempting to find alternative strains, it was also attempted to optimise the substrate. Generally speaking, the substrate consisted of beech saw dust, water and a nutritional supplement. A number of alternatives for beech saw dust were tested. Based on yield, flax shives, rapeseed straw (milled < 3mm), hemp (milled < 3mm) and organic wheat straw (pellets), would be suitable alternatives for beech saw dust. Wheat straw pellets and flax shives are commercially available in that form and therefore would be the more convenient choice. Thirdly, attempts were made to improve the nutritional supplement. Without being able to disclose the ingredients used, we demonstrated that an alternative composition of the supplement allowed the yield to improve from 20.9 to 31.4 g DM/ kg FW of substrate. We also investigated applications of the spent substrate that could add value to the product. Currently the spent substrate is composted and used as an agent to improve the soil/fertilizer. Potentially, the spent substrate could also be used as a feed component. For this the product should be checked against the legal requirements for use as a feed component and be incorporated in the GMPplus Products List. Students of HAS University of Applied Sciences investigated other alternatives. Use of spent substrate as an enzyme source for breakdown of secondary feedstock showed no perspective. Using the spent substrate as a feedstock for bioremediation showed some promise but is still far from a practical application. Lastly, we investigated the possibility to use handheld NIR spectrometers as an aid in monitoring substrate composition in real-time when it is produced in large quantities. For this, 12 handheld spectrometers were compared in a simulation study with respect to accuracy, cost and ease of use. Based on a comparison of 12 handheld spectrometers, Model SYS-IR-R-P (trinamiX) was shown to be the best choice for this application. Subsequently this device was tested in practice.