Jayalath Sanali Upeksha, de Alwis Ajith Priyal
Department of Chemical and Process Engineering, University of Moratuwa, Moratuwa 10400, Sri Lanka.
ACS Omega. 2025 Jul 23;10(30):32564-32586. doi: 10.1021/acsomega.5c00684. eCollection 2025 Aug 5.
The global proliferation of nonbiodegradable petrochemical plastics presents severe environmental, health, and economic challenges, underscoring the urgent need for sustainable alternatives. Polyhydroxyalkanoates (PHAs), a family of biobased and biodegradable polyesters, offer a promising solution with their environmental compatibility, versatility, and ability to mimic conventional plastics. This review explores PHA production, encompassing microbial biosynthesis, metabolic pathways, and innovative extraction methods to optimize production and material properties. Genetic and metabolic engineering advances address cost and scalability barriers, and novel feedstock utilization. Innovations in copolymerization, blending, and nanocomposites have expanded PHA applications across packaging, agriculture, and biomedical fields. The evolution of smart and functionalized PHAs for high-value sectors such as regenerative medicine, drug delivery, and smart packaging further demonstrates their expanded potential beyond conventional bioplastics. Emphasis is placed on integrating PHAs into circular economy models by leveraging waste-derived feedstocks, emerging microbial strategies, including mixed microbial cultures (MMCs), halophilic systems, and aquaculture-integrated production, offer scalable and resilient routes for cost-effective, sustainable PHA biosynthesis. Despite their potential, PHAs remain hindered by challenges involving high production costs, inconsistent mechanical properties, and environmental trade-offs in downstream processing. PHAs are sustainable bioplastics that align competently with Green Chemistry principles, though improvements in energy efficiency and catalytic optimization are required for broader commercial applications. The review highlights novel recovery techniques aligned with a green bioeconomy, including green solvents, supercritical fluid extraction, enzymatic, mealworm, and other biorecovery methods. Integration with circular economy frameworks through waste valorization, biobased feedstocks, and zero-waste biorefinery models further enhances the sustainability of PHA production. Future research must optimize extraction methods, address microplastic risks, and expand into high-value markets. PHAs represent one of the most environmentally promising bioplastics to date due to their complete biodegradability, non-persistent microplastics, and lower emissions, with advancements in production further enhancing their viability. By advancing PHA technologies and fostering interdisciplinary collaboration, PHAs can accelerate the transition to a circular bioeconomy, offering a unique combination of full biodegradability, material tunability, and circular design that positions them as frontrunners in the transition away from fossil-based plastics.
不可生物降解的石化塑料在全球范围内的扩散带来了严峻的环境、健康和经济挑战，凸显了对可持续替代品的迫切需求。聚羟基脂肪酸酯（PHA）是一类基于生物且可生物降解的聚酯，因其与环境的兼容性、多功能性以及模仿传统塑料的能力而提供了一个有前景的解决方案。本综述探讨了PHA的生产，包括微生物生物合成、代谢途径以及创新的提取方法，以优化生产和材料性能。基因和代谢工程的进展解决了成本和可扩展性障碍以及新型原料利用问题。共聚、共混和纳米复合材料方面的创新扩大了PHA在包装、农业和生物医学领域的应用。用于再生医学、药物递送和智能包装等高价值领域的智能和功能化PHA的发展进一步证明了它们超越传统生物塑料的扩展潜力。重点在于通过利用源自废物的原料将PHA纳入循环经济模式，新兴的微生物策略，包括混合微生物培养（MMC）、嗜盐系统和水产养殖综合生产，为具有成本效益的可持续PHA生物合成提供了可扩展且有弹性的途径。尽管PHA具有潜力，但它们仍然受到高生产成本、机械性能不一致以及下游加工中的环境权衡等挑战的阻碍。PHA是符合绿色化学原则的可持续生物塑料，不过要实现更广泛的商业应用，还需要提高能源效率和进行催化优化。该综述强调了与绿色生物经济相一致的新型回收技术，包括绿色溶剂、超临界流体萃取、酶法、黄粉虫以及其他生物回收方法。通过废物 valorization、基于生物的原料和零废物生物精炼模型与循环经济框架相结合，进一步提高了PHA生产的可持续性。未来的研究必须优化提取方法，解决微塑料风险，并拓展到高价值市场。PHA由于其完全可生物降解性、非持久性微塑料和更低的排放，是迄今为止最具环境前景的生物塑料之一，生产方面的进展进一步增强了它们的可行性。通过推进PHA技术并促进跨学科合作，PHA可以加速向循环生物经济的转变，提供完全可生物降解性、材料可调性和循环设计的独特组合，使其成为从化石基塑料转型的领跑者。
