GOALI: Characterizing interactions between water-soluble cellulose derivatives and bacteria that promote efficient polymer biodegradation

NON-TECHNICAL SUMMARY: In recent years there have been significant efforts to develop new polymers that dissolve in water based on materials from biological systems to address the demand for a circular economy. However, knowledge about how these new bio-based polymer products are degraded by microorganisms, which determines their fate in the environment, remains fragmented. This GOALI research will synergize academic and industrial expertise to investigate the chemical and biological contributors to the biodegradation of water soluble polymers (WSPs). Knowledge about how polymer biodegradability depends on various aspects of their chemistry will ultimately guide the design of new biopolymers. In addition, understanding the types and combinations of microorganisms that degrade biopolymers will guide the design of engineered combinations of microorganisms that can more efficiently degrade biopolymers. This project will promote the progress of science and greatly contribute to workforce development through use-inspired research, integrated academic and industrial research experiences, as well as joint academic and industrial advisors. The project will broaden STEM participation through various outreach and educational activities at the K-12 and community college levels. TECHNICAL SUMMARY: This project will provide a deep and systematic understanding of the chemical and biological contributors controlling the fate of water-soluble polymers. Different stages of the bi-directional influences between selected water-soluble cellulose derivatives and bacterial strains will be investigated, including the following: (1) initial polymer binding, (2) subsequent cell responses such as growth, enzyme production and metabolic changes, (3) polymer biodegradation processes, and (4) impact of the polymer degradation products on the cells. Systematic understanding of the connection between the polymer chemistry and biodegradability will be captured by investigating cellulose derivatives with a spectrum of molecular weights as well as modification types and degrees of substitution. Cell responses contributing to the polymer biodegradation processes and outcome will be characterized in culture systems of single microbial strains and rationally designed synthetic consortia of bacteria to identify strategies for promoting cell synergy and efficient polymer biodegradation. Parameters describing the polymer properties, polymer-cell interactions, cell responses and the polymer outcomes will be correlated to direct the design of polymer chemistries, formulations and remediation processes for desirable degradation profiles. The research lies at the intersection of polymer science, biodegradation, environmental science and microbial ecology, and is expected to push the boundaries of knowledge in each field. This project will promote the progress of science and greatly contribute to workforce development through use-inspired research, integrated academic and industrial research experiences, as well as joint academic and industrial advisors. The project will broaden STEM participation through various outreach and educational activities at the K-12 and community college levels. 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.