Tailoring the Growth of Living Materials Towards Sustainable Manufacturing

Traditional manufacturing of polymer composites relies on valuable precursors derived from fossil fuels and energy-intensive processes. Innovation in polymer composites manufacturing strategies should focus on resource recyclability and low carbon footprint procedures. Here, a new paradigm of polymer composite manufacturing valorizing local wastes and using biological growth of living materials to dictate the final product form has been proposed. Living materials comprised of living <i>Saccharomyces cerevisiae</i> (baker’s yeast) within a hydrogel matrix cultured in media derived from bread waste can achieve volume and mass increase through in-situ cell proliferation. The final object shape can be tailored through controlled growth of living materials. For example, by digitally programming the cell viability through UV irradiation or photodynamic inactivation, growth-induced shape control can be achieved. This growth-dictated manufacturing process can be powered by wasted chemical energy present in substances such as food waste, which stands in stark contrast to the energy-intensive processes used for synthetic material manufacturing. After growth, the final material is up to 96 wt% biomass and 590% larger in volume than the initial object. Subsequent enzymatic hydrolysis and regeneration of yeast cell walls within the grown structures enable shape reconfiguration. The proposed biomanufacturing strategy utilizing the growth of living materials with food waste may pave the way for future ecologically friendly manufacturing of materials.