噬菌体介导高温堆肥腐殖化过程的生态调控机制

高温堆肥是有机固废向土壤腐殖质转化的关键环节，但微生物驱动腐殖质形成的机制尚有争议。噬菌体作为地球生物圈中数量最多的生命体，其通过侵染宿主调控微生物群落结构、驱动有机碳循环的生态功能已被大量研究证实，但它在高温堆肥的角色与功能仍是空白。为此，本项目基于高温堆肥噬菌体多样性高与宿主数量大等有利条件，将噬菌体侵染宿主的生态过程与堆肥腐殖化过程联系起来，提出“噬菌体介导高温堆肥腐殖化过程的生态调控机制”假说。以污泥高温堆肥为研究对象，综合运用宏病毒组学、荧光显微计数、16S rRNA高通量测序、傅里叶离子回旋共振质谱等方法，重点研究噬菌体生态特征、细菌群落结构、有机碳化学组分的相互关系，探讨噬菌体裂解宿主释放胞内有机碳介导的生态效应，明确噬菌体对高温堆肥细菌群落结构的影响及驱动腐殖质形成的作用机制，揭示噬菌体介导高温堆肥腐殖化过程的生态调控策略，为发展工程可用的腐殖化调控技术提供科学依据。

Thermophilic composting is an ideal bio-technology for the transformation of organic solid wastes into soil humus, however, the mechanism of humus formation driven by microorganisms is still controversial. Bacteriophages are the most abundant biological entities on the Earth, and play important roles in regulating microbial community structures and driving organic carbon cycle in various ecosystems, but their roles and ecological functions in thermophilic composting are still in blank currently. Based on favorable conditions such as high diversity of bacteriophages and a large number of bacterial hosts in thermophilic composting, the ecological process of bacteriophage infecting host is linked with humification process in this project. A hypothesized mechanism is proposed on the ecological regulation of bacteriophages in humification process of thermophilic composting. Viral metagenome sequencing, epifluorescence microscopy (EFM), 16S rRNA gene high-throughput sequencing and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) will be applied to investigate bacterial and viral diversity as well as the dissolved organic matter (DOM) components, and provide insight on phage-bacterium interactions and their effect on organic carbon transformation in thermophilic composting of sewage sludge. The ecological effects of release of organic carbon components by bacteriophage infecting host will be explored. The regulation mechanism of bacteriophages in microbial community structures and humus formation process will be indicated. The ecological regulation strategies of bacteriophages in humification process of thermophilic composting will be revealed. The results from this project are expected to provide scientific basis for the development of rapid humification technology available in engineering.