CAREER: Catalytic Living Materials Constructed with Engineered Spores and Polymer Scaffolds

Non-technical summary Bacterial spores are like seeds. They are hardy, preserve well, and can grow into living organisms when the conditions are right, even if it requires waiting many years. Like a sunflower seed growing into a sunflower that produces multiple seeds, a bacterial spore can grow into billions of cells that later become billions of spores. Scientists can now engineer bacterial spores to decorate their surfaces with biological machinery called enzymes, a category of proteins that are essential to all life because of their ability to speed up useful chemical reactions. Combining these functionalized spores with engineered polymers enables the production of new materials performing catalytic reactions. This project investigates recipes for creating such materials by engineering both synthetic polymers and bacterial spores, with special emphasis on making materials degrading toxic compounds from the environment. The outcome of this research will establish a foundation for creating a diverse array of materials that can facilitate a wide range of chemical reactions. It will also provide new fundamental knowledge in building engineered interfaces between synthetic materials and bacterial spores. Along with the research activities, educational and outreach programs will be developed for community college students, K12 students, and polymer chemistry students at UC Irvine. Technical summary This project aims to develop robust, intelligent catalytic living materials utilizing dynamic covalent bond formation between engineered polymer scaffolds and B. subtilis spores. In particular, the team will focus on creating living materials for catalytic bioremediation. Because bacterial spores can survive harsh conditions, such as dehydration, nutrient limitation, organic solvents, and oxidative stress, spore-containing composite materials could be produced and stored in a dried form. Upon engineering both the bacterial spores and polymeric materials constituting living materials, they are expected to perform robust catalysis for a wide range of substrates, are stable under dry storage for a long period of time, and are recyclable after use. Specifically, the following four research objectives will be pursued: (1) evaluating various motifs for building a well-defined molecular interface on B. subtilis spores, (2) engineering B. subtilis spores for catalytic bioremediation, (3) synthesizing and studying physical properties of spore-containing living materials. (4) evaluating and engineering catalytic behaviors of living materials. The educational objectives to complement the research activities are (1) the development of an outreach and research program targeting local community college (CC) students and CC transfer students, (2) participation in the outreach program targeting local K12 students, and (3) mentoring and educating students at UCI and leading the polymer chemistry club activities. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.