10004704Advancing MP1, a novel depolymerase for perpetual cradle-to-cradle plastics recyclingClosedCollaborative R&DInnovate UK**PROBLEM** Plastic packaging, and in particular plastic film, can pose significant challenges to recyclers. It is a major problem as it is often co-laminated, containing additives, and contaminated. It can also damage sorting machinery. The widespread collection and reprocessing of plastic film in the UK (and in most developed countries) is limited; just 10% of local authorities in the UK accept all types of plastic film for recycling, thus it frequently reaches landfill. In the UK, 1.2 million tonnes of plastic film were used in 2017\. Based on current collection rates, this suggests that significant amounts of plastic film reach landfill each year in the UK. **OPPORTUNITY** Mellizyme have identified a novel enzyme 'MP1' that can degrade certain bonds within plastics commonly used in plastic films to liberate small molecules. Standard physico-chemical recycling methods leads to loss of plastic quality between recycling rounds. When degraded beyond re-use, this the creates waste for incineration (generating CO2) or landfill (which can leach chemicals into the environment). This is problem is overcome by MP1, as the biological degradation of the plastic film polymers maintains integrity of the small molecules liberated. This supports perpetual cradle-to-cradle recycling. There is significant market opportunity for MP1; globally, just 9% of the 7.82Bn tons of plastic produced in 2015 was recycled, suggestive of a significant opportunity for recyclers to valorise plastics that would be otherwise destined for landfill or incineration. **KEY PROJECT OBJECTIVES** Maturation of Mellizyme technology from TRL3 to TRL5\. The project outputs are critical for subsequent industrial-scale demonstration. **INNOVATIONS** Current state-of-the-art approaches: * Multilayer plastic films can be deconstructed, but this requires energy and chemical-intensive solvent-targeted recovery and precipitation. * Several microbes can degrade some plastics, but this appears to be only of low molecular weight components, rather than the long-chain polymer backbones. * An enzyme isolated from a tree has demonstrated activity against plastic resins, but the reaction mixture requires triazole supplementation. MP1 improvements over this state-of-the-art: * MP1 has activity across many plastic types within different 'families' of plastics. * MP1 does not require any harsh chemical solvents to be used as adjuvants to the reaction. * MP1-type enzymes are fast, with turnover numbers \>1000^s-1 (for comparison, the best enzyme that degrades the ester PET has a turnover number of just 1.2^s-1).