P4SB is about the utilization of the conceptual and material tools of contemporary Synthetic Biology to bring about the sustainable and environmentally friendly bioconversion of oil-based plastic waste into fully biodegradable counterparts by means of deeply engineered, whole-cell bacterial catalysts. These tools will be used to design tailor-made enzymes for the bio-depolymerization of PET (polyethylene terephthalate) and PU (polyurethane), but also for the custom design of a Pseudomonas putida Cell Factory capable of metabolizing the resulting monomers. Pseudomonas putida will undergo deep metabolic surgery to channel these diverse substrates efficiently into the production of polyhydroxyalkanoates (PHA) and derivatives. In addition, synthetic downstream processing modules based on the programmed non-lytic secretion of PHA will facilitate the release and recovery of the bioplastic from the bacterial biomass. These industry driven objectives will help to address the market need for novel routes to valorise the gigantic plastic waste streams in the European Union and beyond, with direct opportunities for SME partners of P4SB spanning the entire value chain from plastic waste via Synthetic Biology to biodegradable plastic. As a result we anticipate a completely biobased process reducing the environmental impact of plastic waste by establishing it as a novel bulk second generation carbon source for industrial biotechnology, while at the same time opening new opportunities for the European plastic recycling industry and helping to achieve the ambitious recycling targets set by the European Union for 2020.