Engineering Microbes to Produce High-Strength Protein-Based Materials

Microbially-synthesized protein-based materials (PBMs) present an appealing alternative to petroleum-derived synthetic polymers. However, their widespread adoption has been hindered by challenges such as the repetitive sequences, high molecular weight of proteins, and skewed amino acid compositions, particularly for high-strength PBMs. In this presentation, I will introduce our recent advances in synthetic biology aimed at overcoming these hurdles. We have developed a range of synthetic biology tools that enable the stable expression of high molecular weight and highly repetitive proteins within engineered microbes. These tools have been instrumental in the microbial production of recombinant spider silk of similar mechanical properties. We further engineered amyloid-silk proteins which have a remarkable propensity to form nano β-crystals, resulting in fibers that possess exceptional mechanical properties. Additionally, we have devised a universal strategy to augment material strength and toughness by incorporating intrinsically disordered mussel foot protein fragments at the termini of these proteins. This approach promotes end-to-end protein-protein interactions, leading to the creation of protein fibers that surpass natural spider silk and petroleum-derived nylon fibers in both strength and toughness. Moreover, these fibers can be produced at a yield of 8 g/L.