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Abstract Background Plastic is widely utilized in packaging, frameworks, and as coverings material. Its overconsumption and slow degradation, pose threats to ecosystems due to its toxic effects. While polyhydroxyalkanoates (PHA) offer a sustainable alternative to petroleum-based plastics, their production costs present significant obstacles to global adoption. On the other side, a multitude of household and industrial activities generate substantial volumes of wastewater containing both organic and inorganic contaminants. This not only poses a threat to ecosystems but also presents opportunities to get benefits from the circular economy. Main body of abstract Production of bioplastics may be improved by using the nutrients and minerals in wastewater as a feedstock for microbial fermentation. Strategies like feast-famine culture, mixed-consortia culture, and integrated processes have been developed for PHA production from highly polluted wastewater with high organic loads. Various process parameters like organic loading rate, organic content (volatile fatty acids), dissolved oxygen, operating pH, and temperature also have critical roles in PHA accumulation in microbial biomass. Research advances are also going on in downstream and recovery of PHA utilizing a combination of physical and chemical (halogenated solvents, surfactants, green solvents) methods. This review highlights recent developments in upcycling wastewater resources into PHA, encompassing various production strategies, downstream processing methodologies, and techno-economic analyses. Short conclusion Organic carbon and nitrogen present in wastewater offer a promising, cost-effective source for producing bioplastic. Previous attempts have focused on enhancing productivity through optimizing culture systems and growth conditions. However, despite technological progress, significant challenges persist, such as low productivity, intricate downstream processing, scalability issues, and the properties of resulting PHA. Graphical abstract more...

Microbial exopolysaccharides (EPS) are high molecular weight carbohydrate-based materials produced and secreted in response to external environmental stress to protect microbial cells. These molecules also contain non-carbohydrate moieties including acetate, pyruvate, phosphate, and succinate along with sugar molecules. EPS has been incorporated into industrial operations as a gelling, emulsifying, and stabilizing agent to increase viscosity. Besides, these molecules have also shown high biocompatibility, immunomodulatory, antitumor, anti-microbial, and anti-viral activity which suggest their possible applications in healthcare. However, these molecules are facing some commercial shortcomings due to low stability, bioactivity, and poor mechanical and tensile strength in comparison to the required standard. Hence use of composites of EPS with other polymers and moieties has been suggested for higher performance. Especially in the context of inorganic moieties like silver, gold nanomaterials, clay, salts, and minerals will add bioactivity and functional sites for the attachment of drug molecules and other compounds. The current review summarizes the higher physical and chemical characteristics of EPS composites with inorganic materials and their immense potential in the biomedical sector. more...