Enhanced mechanical properties of living and regenerative building materials by filamentous Leptolyngbya boryana

Cement-free and cyanobacteria-based living building materials (LBMs) can be manufactured using microbially induced calcium carbonate (CaCO₃) precipitation (MICP) technology, which is regarded as eco-friendly because of the absence of CO₂ gas emissions during the manufacturing process. Here, we report that photosynthetic and filamentous cyanobacterium Leptolyngbya boryana GGD can precipitate substantial amounts of CaCO₃ with biofilm formation in our optimized medium. Compared to coccoid cells, filamentous cells have an extensive surface area that can efficiently agglomerate the formation of granular materials and fill the void spaces by forming bridging microstructures along with precipitated CaCO₃ in LBMs, which can enhance the mechanical properties of LBMs. Regenerative LBMs can possibly be reconstructed using old materials from parent LBMs without the addition of GGD strain cells. The physicochemical properties of the filamentous GGD strain hold promise as valuable components for maintaining the structural integrity of LBMs.