短期填埋龄垃圾堆体内微生物群落结构与种群分布特征

填埋垃圾的稳定化过程一般经历好氧过渡、水解酸化、初期产甲烷及稳定产甲烷阶段,固相垃圾的厌氧水解酸化阶段常被视为垃圾降解的限速步骤,而这一阶段微生物的降解作用是影响垃圾稳定化进程的关键.以青岛市小涧西生活垃圾填埋场短期填埋龄垃圾为研究对象,采用MiSeq高通量测序研究了填埋龄0～1、1.0～1.5、1.5～2 a垃圾堆体内微生物的群落结构多样性及种群分布特征.结果表明,0～1 a填埋龄垃圾微生物多样性高于1.0～1.5 a和1.5～2 a垃圾堆体,且微生物多样性整体上随填埋深度呈降低趋势.参与垃圾降解细菌多样性比真菌更丰富,而真菌多样性随填埋区域、填埋龄的不同呈现更显著的差异.参与短期填埋龄垃圾降解的细菌中,Firmicutes在填埋层上层为优势菌门,最大比例达到65%,Proteobacteria在填埋层中下层为优势菌门,最大比例达到88%.填埋上层细菌菌属以Defluviitoga、Aerococcus、Clostridium III和Proteiniphilum为主,而在中下层以Thiopseudomonas、Sporosarcina和Eionea为主.真菌主要包括3个菌门,Ascomycota在各点位均为最优势菌门,属水平上Kernia及Aspergillus作为常见的腐生菌属,在不同点位均有较高的丰度.冗余分析表明短期填埋龄垃圾堆体内微生物不同时空分布存在显著差异性,且细菌群落结构的变化受pH值影响较大,而真菌群落结构的变化与垃圾有机质密切相关.

Microbial community structure and population distribution characteristics in short-term landfill refuse

The stabilization process of landfill waste generally went through aerobic transition, anaerobic acidification, initial methanogenesis and stable methanogenesis processes. The hydrolysis-acidification phase of solid waste was usually regarded as a rate-limiting step during the whole anaerobic degradation process, and the microbiological degradation in this period was the key to the stabilization of refuse. Based on the short-term landfill refuse with landfill age of 0~1 year, 1.0~1.5 year and 1.5~2 year from Qingdao Xiaojianxi Landfill, their microbial diversity and community structure distribution characteristics of the landfill were investigated by MiSeq high-throughput sequencing. The results show that the microbial diversity of 0~1 year landfill waste was higher than those of 1.0~1.5 and 1.5~2 years landfill waste, and the microbial diversity decreased with the overall landfill depth. The diversity of bacterial involved in refuse degradation was more abundant than that of fungi, while the diversity of fungi showed more significant differences with different landfill areas and landfill ages. Among the bacteria involved in the short-term landfill waste degradation, Firmicutes was the dominant phylum in the upper layer of the landfill, with a maximum proportion of 65%, and Proteobacteria was the dominant phylum in the deep layer of the landfill, with a maximum proportion of 88%. The upper bacteria of the landfill were mainly consisted of Defluviitoga, Aerococcus, Clostridium III, and Proteiniphilum, while in the middle and deep layers, Thiopseudomonas, Sporosarcina and Eionea were the main genus. The fungi mainly consisted of three phyla, and Ascomycota was the most dominant phylum at each point. Keronia and Aspergillus were the common genus of saprophytic genus, which had high abundances at different points. The redundancy analysis shows that the distribution of microorganisms in short-term landfill refuse presented significant differences in the dimensions of time and space. The change of bacterial community structure was greatly affected by the pH of the landfill, and the change of fungal community structure was closely related to the degradation of waste organic matter.