Hierarchical spatial organization stabilizes algal-fungal living materials and enables sustained carbon fixation

Engineering stable multicellular living materials remains difficult because distinct partners require incompatible local microenvironments, while sustained cooperation depends on integration across multiple spatial scales. Here we show that hierarchical spatial organization stabilizes algal-fungal living materials and enables sustained carbon fixation. Compartmentalized seed-seedcase units create partner compatible local niches for Chlorella vulgaris and Pleurotus ostreatus, while fungal outgrowth bridges neighboring units into an integrated artificial lichen. This transition converts localized coexistence into a mechanically coherent assembly that sustains net CO2 drawdown together with O2 production in closed systems and restores carbon fixation activity after repeated CO2 replenishment. A printable formulation further enables macroscopic architecture with enhanced volumetric carbon-fixation performance. Transcriptomics reveals division of labor between algal carbon fixation and fungal redox and matrix support functions, whereas perturbation assays demonstrate functional robustness. These results establish hierarchical spatial organization as a design principle for stable cooperative living materials. TeaserProgrammable algal-fungal assemblies turn spatial design into durable carbon capture.