Bacterial spores as a modular platform for the production of amyloids for materials

We present a proof-of-concept platform in which amyloids are displayed on the surface of engineered Bacillus subtilis spores for bioengineered materials. Amyloids possess high tensile strength, elasticity, and tunable assembly, but their use is limited by inaccessible native sources and low-yield or toxic heterologous expression. Spore-based display addresses these limitations by leveraging natural sporulation for controlled, surface-localized production without cross-membrane secretion, enabling simple purification by centrifugation. In this research article, spores were engineered to display native amyloid TasA and Humboldt squid suckerins 9 and 10 as fusions to the coat protein CotY. Western blotting and X-34 staining confirmed amyloid production and fibril formation, while semi-quantitative analysis determined binding sites. Atomic force microscopy revealed altered stiffness and surface ultrastructure, and incorporating these spores into resin-based 3D printing modified tensile strength. This modular, potentially scalable platform bypasses current production bottlenecks, leveraging established industrial infrastructure for future scale-up and rapid screening of synthetic amyloid-like proteins.