基于密粘褶菌改性作用的秸秆-畜禽粪便好氧堆肥腐殖化的驱动机制研究

The degradation and conversion of lignocellulose to humus is the limiting factor of humification process during organic solid waste composting. Exploring the theory and methods of efficient conversion of lignocellulose to humus is of great significance to the optimization of composting technology and improvement of composting efficiency. Our previous study showed that modification of wheat straw with Gloeophyllum trabeum significantly increased the humus content of aerobic composting of wheat straw-pig manure and accelerated humification process. In the present project, the alterations of modified wheat straw structure will be investigated using state-of-the-art analytical techniques. The types and contents of modified products phenolic compounds will also be determined. Thus, the modification pattern of wheat straw by Gloeophyllum trabeum can be uncovered. High-throughput sequencing and proteomic approaches will be employed to reveal the responses of lignocellulose-degrading microbial community structure and lignocellulytic enzymes during modified wheat straw-pig manure composting to changes in wheat straw structure. The conversion pattern of phenolic compounds and formation pattern and structural characteristics of humus during composting will be analyzed through spectral, NMR and XPS methods, to establish quantitative relationships between phenol conversion and humus formation. The outcome of this project will elucidate the mechanism of humification process driven by modification action of Gloeophyllum trabeum. The results obtained from this project will provide a theoretical basis for the development and application of efficient technology for organic solid waste composting.

木质纤维素降解转化为腐殖质是影响有机固体废弃物堆肥腐殖化进程的限制因素，探究促进木质纤维素高效转化为腐殖质的理论和方法对优化堆肥工艺和提高堆肥效率具有重要意义。前期研究发现，密粘褶菌改性麦秸能够显著提高麦秸-猪粪好氧堆肥的腐殖化程度，加速堆肥腐熟。本项目拟通过先进的表征手段对改性麦秸的结构变化进行研究，确定改性产物酚类物质的种类和含量，揭示密粘褶菌改性木质纤维素的作用模式；以改性麦秸-猪粪混合堆肥体系为研究对象，利用高通量测序技术和蛋白质组学方法揭示堆肥木质纤维素降解功能微生物的群落结构和降解酶对麦秸结构变化的响应特征，通过光谱、核磁共振和X射线光电子能谱手段解析堆肥过程中酚类物质的转化规律以及腐殖质的形成规律和结构特征，建立酚类物质转化和腐殖质形成的定量关系，阐明密粘褶菌改性作用对腐殖化过程的驱动机制，为有机固体废弃物高效堆肥技术的开发和应用提供理论依据。

好氧堆肥是实现有机固废资源化利用的重要手段。有机固废原料中木质纤维素是一类结构复杂、化学性质稳定的有机碳，其降解和转化与堆肥的腐殖化和稳定化进程密切相关。木质纤维素降解转化的中间产物酚类化合物，是腐殖质合成的重要前体物质，也是影响腐殖质化学结构和性质的重要因素，然而堆肥中酚类化合物的转化和归趋及其对腐殖质官能团形成的影响尚不明晰。本研究利用密粘褶菌改性麦秸，再和猪粪进行混合堆肥，以此混合堆肥体系为研究对象，通过扫描电镜（SEM）和X射线衍射技术（XRD）表征密粘褶菌改性对麦秸微观结构的影响，利用高效液相色谱-电喷雾电离质谱技术（HPLC-ESI-MS）对酚类产物进行定量分析，利用固体核磁共振（ssNMR）技术分析堆肥过程中腐殖质碳结构组成的动态变化，建立酚类物质转化和腐殖质形成的定量关系，结合高通量测序技术研究改性堆肥中微生物群落的演替规律，阐明堆肥微生物群落结构和代谢活性对酚类产物的响应机制及其对腐殖化过程的驱动机理。主要结论如下：密粘褶菌改性麦秸显著提高了没食子酸、原儿茶酸、对香豆酸等酚类化合物含量，通过改变底物结构和性质加速堆肥木质纤维素的生物降解和腐殖化进程；密粘褶菌改性通过促进酚类化合物转化为腐殖质芳香族官能团，提高腐殖质化学结构的稳定性；密粘褶菌改性增强酚类化合物对细菌群落的影响，引起产漆酶的细菌类群丰度增加，从而促进酚类化合物转化为腐殖质。研究结果为理解和调控有机固废堆肥中腐殖质合成过程提供了科学依据和技术支撑。