PLA Degrading Enzymes from Metagenomic Databases

In this study, we report the discovery and characterization of novel polylactic acid (PLA)-degrading enzymes sourced from the MGnify metagenomic database. Six candidate enzymes were initially identified, with subsequent efforts focused on two metagenomic enzymes that exhibited better activity and stability compared to the others. A biochemical characterization combined with N-terminal modifications was performed to assess the impact of N-terminal length and composition on enzyme activity and solubility. Our results underscore the significant potential of metagenomic resources for uncovering new biocatalysts, while also highlighting the critical role of protein engineering in addressing limitations such as low solubility, poor thermostability, and suboptimal expression in heterologous hosts. This work advances the development of efficient biocatalysts for the sustainable degradation and recycling of PLA.