Bending and Compressive Behavior of a Co-cultivated Mycelium-Bacteria Based Composite

This research investigates compressive and flexural behavior of a composite formed through a double binding process given by co-cultivation of a bacterial and fungal strain. Co-cultivation in this research refers to the simultaneous inoculation of the bacterial partner Sporosarcina Pasteurii and the fungal partner Ganoderma Lucidum into one composite. The paper describes the investigation of the impact of microbially induced calcium carbonate precipitation (MICP) as source of mineral substrate. The motile bacterial cells are using the fungal mycelium as a network of transportation, therethrough spreading an enzyme, which catalyses a chemical reaction, resulting in homogeneous creation of micro-scale calcium carbonate minerals attached to and in between mycelium hyphae. The research compares three compositions of substrate mixture and drying methods of co-cultivated species against a monocultivation of G. Lucidum and investigates the microbial morphology, and the influence of the double binding process on flexural and compressive strength. Through microscopic imaging, increased density of fungal growth in co-cultured specimen was observed. Additionally, higher mechanical properties in both bending and compression have been found in testing specimen with MICP as secondary binding process, with the highest flexural modulus of 6,94 MPa and compressive modulus of 7,27 MPa in pressed specimen.