(647f) Materials Made By Bacteria

Engineered living materials (ELMs) are innovative composites that integrate living cells within a biopolymer matrix, drawing inspiration from natural materials such as bones, wood, and biofilms. By leveraging synthetic biology, ELMs acquire unique, non-natural properties, enabling them to serve as living sensors, therapeutic agents, biomanufacturing platforms, electronic devices, energy converters, and structural materials. The biopolymer matrix not only structures the material but also influences its mechanical and physical characteristics by managing the composition, structure, and function of the bulk material. A major challenge in the field of ELMs has been the engineering of cells to self-organize within a genetically encoded synthetic matrix.

Before my research, most large-scale ELMs either needed extensive processing for assembly or relied on natural biomaterials like bacterial nanocellulose, offering limited tunability. In this work, I introduce the first large-scale ELM developed from scratch, using genetically modified Caulobacter crescentus bacteria. By engineering these bacteria to express self-interacting proteins, I created a synthetic extracellular matrix that orchestrates cell organization across multiple scales, leading to the formation of living materials of centimeter size.

A standout feature of these newly developed ELMs is their genetically modifiable mechanical properties. I demonstrated that this living material can be endowed with complex enzyme mixtures for biological catalysis. Additionally, it retains the inherent capability of individual C. crescentus cells to capture cadmium from contaminated solutions, making it a superior option for heavy metal removal compared to a suspension of individual cells, due to its macroscopic, solid form.

These de novo ELMs can be molded and used as binding agents to create sturdy hybrid materials. They can also be dried at room temperature and rehydrated in fresh medium to generate new materials, simplifying their transportation and storage. This research establishes a foundation for cultivating ELMs with specific physical and mechanical properties, thereby opening avenues for the development of multifunctional, self-healing materials.