Polyhydroxyalkanoates (PHAs), naturally produced polyesters, are gaining attention in the biodegradable polymer market due to their high biodegradability and versatility. They display sufficient functional properties to replace some of the 250 MTs of plastics used worldwide today, especially in the substitution of PET, which is widely used in soft drink bottles to electronics casing. A key challenge is in producing PHAs that are cost and performance competitive with conventional fossil-based polymers. Recent research has discovered that PHA polymers are naturally produced by some bacteria within the bacterial cell and can be extracted or processed for use in many applications-packaging, moulded goods, adhesives, films, etc. Work has been underway to determine if they can be grown in genetically modified plants. Despite positive results, many publications and patents on eco-compatible packaging materials, the production of biopolymers from natural sources has been limited, mainly due to difficulties in processing of natural materials, incompatibility at the interface natural fillers-polymeric matrices, poor mechanical properties, possible toxicity due to natural material degradation and moisture sensitivity, high raw material cost, etc. This project will build on promising preliminary research results into the growth of genetically modified cyanobacteria in wastewaters to produce PHAs. Cyanobacteria are a group of oxygen-evolving photosynthetic bacteria with short generation time, and are the sole prokaryotes that accumulate PHA by oxygenic photosynthesis, having potential for PHA cultivation in wastewaters. Olive oil wastewater will be recovered and reused to obtain PHA biopolymers for use as advanced packaging material. A valorisation of the waste materials will be obtained for using the leftover biomass (from biopolymer production) for biodiesel production and for the extraction of chemicals and natural fillers for Polyhydroxybutyrate (PHB)-based composites.