Life cycle design of polyhydroxyalkanoates (PHA)

The global plastic crisis demands sustainable polymer design and production across the full life cycle. Polyhydroxyalkanoates (PHAs), a family of biodegradable polyesters produced by microorganisms, provide a representative model for circular material development and applications. This review summarizes advances in microbial chassis engineering, seawater-based Halomonas biomanufacturing, and low-energy downstream processing that together reduce freshwater use, energy input, and process complexity. The structural versatility of PHA supports applications ranging from compostable packaging to long-term biomedical devices. End-of-life options, including biodegradation, anaerobic digestion, and chemical recycling, enable efficient material recovery, and reintegration into natural carbon cycles. Life cycle assessments consistently show reductions in greenhouse-gas emissions, fossil-resource dependence, and marine eutrophication relative to conventional plastics. Remaining challenges include lowering production costs, improving material performance, and developing standardized biodegradation and circular-economy frameworks. Integration on synthetic biology, materials science, and industrial ecology help shape design principles for sustainable PHA-based polymer systems.