Characterization and Optimization of Biocatalysts for New Recycling Technologies

While the term “plastic” refers to a variety of chemically distinct compounds, these materials are all prized for one key property: incredible chemical stability. Consequently, plastics have become a crutch for modern society, both industrially and at-home. However, mechanical recycling initiatives have proven largely ineffective and uneconomical, which has led to a widespread accumulation of plastics and microplastics in both terrestrial and aquatic ecosystems. The limitations of physical recycling have increased interest in alternative protocols like chemical recycling methods. This project explores an intriguing biochemical approach which involves enzymes that can catalyze the degradation of specific synthetic polymers. This study investigates five novel nylon-degrading enzymes, previously isolated from thermostable organisms. The primary objective of this research is to develop and refine procedures for the expression and purification of these nylonases. The enzymes were overexpressed in Escherichia coli hosts and subsequently purified using advanced chromatographic techniques, including Fast Protein Liquid Chromatography (FPLC) and size exclusion chromatography (SEC). The optimization of these purification procedures is critical, as it ensures that subsequent assays are conducted with highly purified enzyme samples, while minimizing contaminants and improving sample yield. Future research directions will involve a detailed mechanistic examination of the enzymatic autocleavage and the nylon degradation. An additional goal aims to crystallize the proteins to analyze their active sites. This comprehensive approach is expected to advance our understanding of enzymatic plastic degradation and contribute to the development of more effective recycling technologies.