Abstract：
Traditional plastics reshaped the society thanks to their brilliant properties and cut-price manufacturing costs. However, their protracted durability and limited recycling threaten the environment. Worthy alternatives seem to be polyhydroxyalkanoates, compostable biopolymers produced by several microbes. The most common 3-hydroxybutyrate homopolymer has limited applications calling for copolymers biosynthesis to enhance material properties. As a growing number of researches assess the discovery of novel comonomers, great endeavors are dedicated as well to copolymers production scale-up, where the choice of the microbial carbon source significantly affects the overall economic feasibility. Diving into novel metabolic pathways, engineered strains, and cutting-edge bioprocess strategies, this review aims to survey up-to-date publications about copolymers production, focusing primarily on precursors origins. Specifically, in the core of the review, copolymers precursors have been divided into three categories based on their economic value: the costliest structurally related ones, the structurally unrelated ones, and finally various low-cost waste streams. The combination of cheap biomasses, efficient pretreatment strategies, and robust microorganisms paths the way towards the development of versatile and circular polymers. Conceived to researchers and industries interested in tackling polyhydroxyalkanoates production, this review explores an angle often underestimated yet of prime importance: if PHAs copolymers offer advanced properties and sustainable end-of-life, the feedstock choice for their upstream becomes a major factor in the development of plastic substitutes.
摘要：
传统塑料因其卓越的性能和低廉的制造成本而重塑了社会。然而,它们持久的耐用性和有限的回收利用威胁着环境。有价值的替代品似乎是聚羟基链烷酸酯，由几种微生物产生的可堆肥生物聚合物。最常见的3-羟基丁酸酯均聚物具有有限的应用,要求共聚物生物合成以增强材料性质。随着越来越多的研究评估新型共聚单体的发现，也致力于共聚物生产规模的扩大，其中微生物碳源的选择显著影响整体经济可行性。潜入新的代谢途径，工程菌株，和尖端的生物过程策略，这篇评论旨在调查有关共聚物生产的最新出版物，主要关注前体来源。具体来说,在审查的核心，共聚物前体根据其经济价值分为三类：最昂贵的结构相关的，结构上不相关的，最后是各种低成本的废物流。廉价生物质的组合，有效的预处理策略，和强大的微生物通向多功能和圆形聚合物的发展道路。构想给有兴趣解决聚羟基链烷酸酯生产的研究人员和行业，这篇综述探讨了一个经常被低估但最重要的角度：如果PHAs共聚物提供先进的性能和可持续的报废，上游的原料选择成为塑料替代品开发的主要因素。
