剩余活性污泥处理是世界性难题。我们在前期研究发现处理环氧丙烷(PO)皂化废水的活性污泥经驯化可利用含挥发性脂肪酸（VFAs）废水大量积累PHA。同时发现该污泥菌群是已知的具有合成PHA能力的微生物占比最高的污泥菌群，比例达57.8%。以PO皂化废水剩余污泥为材料开展研究，不仅可以解决废弃物资源化的问题，还可为活性污泥中微生物组研究提供丰富的资料，具有潜在应用价值。本项目拟利用不同VFAs条件驯化PO皂化废水污泥富集PHA合成菌群，研究驯化过程中菌群结构与具有合成PHA能力菌群丰富度变化规律，揭示不同VFAs驯化条件与PHA合成菌群演替间的内在关联；同时挖掘驯化后污泥菌群PHA代谢相关基因，分析菌群PHA代谢通路，明确不同菌种来源PHA代谢相关基因在积累PHA过程中的作用，初步阐明含VFAs废水中污泥菌群混合培养合成PHA机制，为实现规模化利用剩余污泥生产PHA奠定理论基础。

The treatment of residual activated sludge is one of the global problems. In our previous research, the activated sludge which could treat propylene oxide (abbreviated as PO) saponification wastewater, could utilize wastewater containing volatile fatty acids (abbreviated as VFAs) to accumulate PHAs after acclimation. There are about 57.8% of PHAs-accumulating organisms (abbreviated as PHAAOs) in this activated sludge, of which proportion is highest among all kinds of activated sludge. The study of PO activated sludge can not only solve the utilization of waste resource, but also offer materials for the research of microbiome in the activated sludge. In this project, PHAAOs in the PO saponification wastewater activated sludge will be firstly acclimated and enriched to reveal the inherent relationship between the supplement of different VFAs and the bacterial community succession. In addition, the bacterial community structure and the richness of PHAAOs in the sludge were explored. Genes related to PHAs metabolism in different acclimated activated sludge metagenomics were investigated, and the expression levels of these genes were also detected. As a result, the possible metabolic pathway of PHAs can be verified, and the roles of PHAs metabolism associated genes from different microbes were clarified. This project may be propitious to elucidate the PHAs biosynthesis mechanism of mixed microorganisms in VFAs containing wastewater, and provide theory base for the utilization of PO wastewater residual sludge in large scale.