Recent advances and challenges in low-cost biosynthesis of polyhydroxyalkanoates: A review

Polyhydroxyalkanoates (PHAs) are promising bioplastics that can address environmental concerns caused by petroleum-based plastic waste pollution. However, PHA commercialization remains challenging due to high production costs. This review focuses on three cost-reduction strategies: utilizing waste resources as feedstocks, employing extremophiles as producer strains to enable non-sterile production, and applying genetic engineering to enhance PHA yields. Moreover, the economic analysis of PHA production from various wastes was systematically summarized and discussed. While the reviewed methods show promise, key challenges must be overcome to enable commercial-scale production. Future efforts should prioritize efficient pretreatment, metabolic engineering of robust strains, intelligent bioprocess design, and comprehensive sustainability assessments to integrate PHA production into a circular bioeconomy.