The mushroom-forming fungi Pleurotus ostreatus (PO), Trametes versicolor (TV) and Schizophyllum commune (SC) are known to effectively colonise organic material. These fungi were grown on the aquatic fern Azolla filiculoides (AF), the fastest growing plant on Earth, and that can fix its own nitrogen. SC showed the best growth on AF. Therefore, growth of this fungus was determined under microgravity conditions and high radiation dosage (up to 200 Gy) and related to melanin production. To make fungal composite materials, freeze dried and ground AF was inoculated with the melanin producing SC strain 227. Additives were added to create a paste like structure that can be used for 3D printing fungal bio-composites in different shapes.