Bioplastics from Waste

Abstract Polyhydroxyalkanoates (PHAs) are biodegradable polymers that offer a sustainable alternative to conventional plastics while adding value to waste products such as sewage sludge. The main challenge in their production is the high cost. This review, conducted in accordance with the PRISMA methodology, focuses on the use of mixed microbial cultures and renewable raw materials, primarily volatile fatty acids from sludge, to make PHA production viable. It summarises research on substrates, the aerobic dynamic feeding strategy for biomass enrichment, operational conditions and reported yields. The work outlines the process from substrate acquisition to polymer production, highlighting the need for optimised conditions to scale up this promising bio-based technology.