Polyhydroxyalkanoates (PHAs) are bio-polyesters of hydroxyalkanoates that accumulate intracellularly in case of prokaryotes, as cytoplasmic granules, under carbon rich and paucity of nitrogen, phosphorous, sulphur and oxygen where it can serve as carbon and energy source under nutrient limiting condition and/or environmental stress conditions. In adverse growth conditions, many bacteria have ability to store nutrients in form of PHA granules using their specific metabolic pathways during stationary growth phase, in the presence of high levels of carbon containing nutrient sources. Bacterial PHAs have generated attention as an alternative to petroleum derived synthetic plastics. It possesses the characteristic physico-chemical properties comparable to the synthetic plastics. These properties of PHAs can be improved by blending of PHAs with other natural polymer like starch, cellulose and semisynthetic polymers like poly lactic acids and polycaprolactones. Being eco-friendly, biodegradable and biocompatible; major PHAs such as, Polyhydroxybutyrate (PHB) and Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) have found numerous vital applications in pharmaceutical, biomedical, textile, cosmetic, agricultural, treatment of waste water and have been successfully employed for Food packaging industries. This review provides a comprehensive knowledge about the world of PHAs covering its major aspects, namely its chemical nature and structure, biosynthesis, various methods of screening of potential PHA producing bacteria along with properties, several techniques used for its recovery and further characterization.

聚羟基链烷酸酯（PHA）是羟基链烷酸酯的生物聚酯，在原核生物的情况下，作为细胞质颗粒，在富含碳且氮，磷，硫和氧稀少的情况下在细胞内积累，在营养限制条件下，它可以作为碳和能源，和/或环境压力条件。在不利的生长条件下，在存在高水平的含碳营养源的情况下，许多细菌具有在固定生长阶段使用其特定的代谢途径以PHA颗粒形式存储营养的能力。细菌PHAs作为石油衍生的合成塑料的替代品已引起关注。它具有可与合成塑料媲美的特征理化特性。通过将PHAs与其他天然聚合物（如淀粉，纤维素和半合成聚合物，如聚乳酸和聚己内酯）混合，可以改善PHA的这些特性。环保，可生物降解和生物相容；主要的PHA，例如聚羟基丁酸酯（PHB）和聚（3-羟基丁酸酯-co-3-羟基戊酸酯）（PHBV）已在制药，生物医学，纺织，化妆品，农业，废水处理中找到了许多重要的应用，并已成功应用用于食品包装行业。这篇综述提供了有关PHAs世界的全面知识，涵盖其主要方面，即其化学性质和结构，生物合成，筛选可能产生PHA的细菌的各种方法及其特性，用于其回收和进一步表征的几种技术。