Synthetic Remediation Biology: Asgard Detoxification of Synthetic Firefighting Foam for Environmental Sustainability
Abstract
Synthetic firefighting foam, especially aqueous film forming foams (AFFF), contains the toxic compounds perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). Chronic exposure to these perfluoroalkyl toxins can lead to adverse health effects such as endocrine disruption, infertility and carcinogenesis. This project aims to use synthetic biology and synthetic enzymology means to address the growing problem of polyfluoalkyl substances (PFASs) contamination in the environment. It has been reported that PFASs can be degraded by enzyme catalyzed humification reactions (ECOHRs), but the limited degradation or defluorination capacity of wild-type microbes and enzymes necessitates engineering strategies to improve their potential for bioremediation. In this study, we endeavor to engineer novel enzymes, in particular laccases, with defluorinating activity towards PFOA and PFOS and deploy direct evolution strategies to enhance their biocatalytic performance. To facilitate downstream on-site bioremediation strategies, we also engineered recombinant laccases into the freshwater organism chassis, Chlamydomonas reinhardtii, employing several molecular designs to enhance transgene expression and extracellular protein production. The expressed laccases were shown to have functional catalytic activities and work is ongoing to examine their PFOA/PFOS-degradation capabilities. Subsequent whole-ecosystem approaches can be envisioned with the co-deployment of engineered AFFF-detoxifying enzymes (ADE)-expressing freshwater organisms and choice biosorption flora at sites of concern. Through this proposal, we seek to maintain planetary health by offering a bio-based approach to mitigation of anthropogenic activities in the aerospace industry.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 10, 2023
- Accession Number
- AD1224917
Entities
People
- Yew W. Shan
Organizations
- National University of Singapore