Abstract: Polyhydroxyalkanoates (PHA) are biodegradable plastics synthesized by microorganism，which can be used as a substitute of chemical plastics. Synthesizing PHA by pure cultures is expensive due to the use of glucose and other high-quality substrates and the requirement of sterilization for the process，seriously restricting the widespread use of PHA; while synthetizing PHA by mixed cultures can use waste as substrate thus significantly reducing cost. The purpose of this paper is to describe the research advances in PHA production by mixed cultures，such as its history，synthesis mechanism，production process，and extraction method. The development of PHA production by mixed cultures is reviewed; two main synthesis mechanisms are described; metabolic pathways of different substrates to synthesize PHA are introduced; a three-stage synthesis process and product extraction are addressed; and recent research trends are summarized. Future research in this area should be focused on increasing concentration of mixed cultures and capacity of using real waste.

Key words: PHA, biodegradability, mixed cultures, biotechnology, polymers, synthesis

摘要： 聚羟基脂肪酸酯（PHA）是微生物体内合成的可生物降解塑料，可以作为化学塑料的替代品。利用纯培养微生物发酵的合成方法由于使用葡萄糖等优质底物及过程需灭菌等原因，产品成本较高，严重制约了PHA的广泛使用；混合菌群利用废弃物合成PHA有效降低了纯培养方法的生产成本，因此受到人们越来越多的关注。本文对混合菌群合成PHA的历史沿革、合成原理、生产工艺、提取方法等方面进行了系统综述。回顾了混合菌群合成PHA的发展历程，简述了两种主要的合成机理，介绍了不同底物合成PHA的代谢途径，重点阐述了混菌合成PHA的三段式工艺和产物提取方法，同时也对新近的研究动态进行了分析总结。指出提高混菌浓度与利用实际废弃物的能力将成为未来研究的关键。

关键词: 聚羟基脂肪酸酯, 可生物降解性, 混合菌群, 生物技术, 聚合物, 合成