外接菌种对污泥堆肥效能及堆体细菌群落的影响

以污泥、锯末、蘑菇渣为堆肥原料,分阶段添加高温复合菌和白腐真菌,通过测定温度、pH、有机质、水溶性有机碳、含水率、总氮、NH_4~+-N、NO_3~--N和种子发芽率,比较了外接菌种对堆肥效能的影响.利用高通量测序技术,研究了污泥堆肥过程中细菌群落结构变化及外接菌种对细菌群落的影响.结果表明,外接菌种可以延长堆体高温持续时间,降低氮损失,加快堆体腐熟脱毒.在整个堆肥过程中,细菌群落结构发生了较大的演变,同一堆肥的不同阶段的细菌群落结构相似性较低,同一时期不同堆肥的细菌群落结构相似性较高.外接菌种提高了堆体中细菌群落的丰富度,增加了高温期优势菌的所占比例,但未改变优势菌的种类.典型对应分析(CCA)表明pH对细菌群落结构的影响最大,温度主要与9个菌属呈正相关关系.

Effects of Exogenous Microorganism Inoculation on Efficiency and Bacterial Community Structure of Sludge Composting

In this study, municipal sludge, sawdust, and mushroom residues were used as raw materials for composting, and thermophiles and white-rot fungi were added into the compost in stages. By measuring physicochemical factors, including temperature, pH value, organic matter, water-soluble organic carbon, moisture content, total nitrogen, NH₄⁺-N, NO₃^--N, and germination index during the composting process, the effect of exogenous bacteria inoculation on the efficiency of compost was determined. By means of high-throughput sequencing technology, the variation of bacterial community structure and the impact of exogenous bacteria inoculation on bacterial community structure during sludge composting were also investigated. The results showed that the inoculation extended the high temperature duration, decreased the nitrogen loss, and accelerated the decomposition and detoxification of the compost. During the entire period of composting, the structure of bacterial community changed significantly. There was low similarity of bacterial community structure among different stages of the same composting, but high similarity was observed in different composting of the same period. The inoculation of thermophilic bacteria improved the abundance of bacterial community and increased the proportions of dominant genera in thermophilic phase, but changed no species of dominant genera. Canonical correspondence analysis showed that pH had the highest influence on the structure of bacterial community and that temperature possessed positive correlation with nine genera.