Biological polyethylene deconstruction initiated by oxidation from DyP peroxidases

Polyethylene (PE) is the most commonly used plastic on Earth due to its favorable material properties such as high ductility, mechanical strength, and bond homogeneity that make the material resistant to deconstruction. However, the lack of robust recycling infrastructure for PE end-of-life management is leading to an estimated 4 million tons of environmental accumulation annually, with implications for human and environmental health. Biological deconstruction and upcycling could potentially aid in PE waste management by allowing for high-yield conversion of waste plastics to high value products, although such processes are not yet possible. In this work, we mined the gut of low-density PE (LDPE) fed mealworms that can reduce LDPE molecular weight by >40% and discovered dye decolorizing peroxidases (DyPs) that oxidized LDPE, initiating biological deconstruction. A plastic-active DyP is characterized by a hydrophobic loop near its active site that helps mediate binding and tunes activity. LDPE oxidation is driven by surface exposed residues proximal to the active site enabling activity on polymeric substrates. Our work provides robust evidence for enzymatic LDPE deconstruction and identifies molecular targets for further development to realize scalable biological LDPE upcycling. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=41 SRC="FIGDIR/small/640435v1_ufig1.gif" ALT="Figure 1"> View larger version (15K): org.highwire.dtl.DTLVardef@146b8fborg.highwire.dtl.DTLVardef@1a72adorg.highwire.dtl.DTLVardef@5ece5forg.highwire.dtl.DTLVardef@3ee20a_HPS_FORMAT_FIGEXP M_FIG C_FIG