生活垃圾堆肥过程中细菌群落演替规律

摘要

The PCR-DGGE technique was used to study the dynamic succession law of bacterial communities during composting of Municipal Solid Waste (MSW). The microbial metagenomic DNA was extracted from samples in different periods of composting,and the V3 region of 16S rDNA was amplified for analyzing the change of the bacterial community during the composting process.DGGE prints showed that the bacterial community changed dramatically with the rise of temperature. New predominant bacteria appeared at the end of the composting process. This indicated that the bacterial community changed in different composting periods. Clustering analysis results showed that 14 samples were divided into two families at 55 ℃. The similarity of the two families was only 13％ , indicating that the bacterial community structure was different in the normal temperature process ( ＜ 55 ℃ ) and high temperature process ( ＞ 55 ℃ ), The results of DNA sequencing showed that: caterpillar pathogen H. obtusa and human waste sample gene were detected in the rising temperature period; thermophilic microbe Clostridium thermocellu, which can decompose cellulose, was the dominant group in the high-temperature composting; and, lots of uncultured bacterial appeared when the temperature was lower than 55 ℃.%应用PCR-DGGE技术研究生活垃圾堆肥过程中的细菌群落演替规律,对堆肥不同时期的宏基因组DNA进行提取,扩增16S rDNA的V3区,分析生活垃圾堆肥过程中细菌群落的变化.DGGE图谱表明,随着堆体温度的升高,DNA条带表现出了明显的动态变化,降温期出现了新的优势条带并趋于稳定,说明堆肥不同时期的细菌群落发生了更替.对条带分布进行聚类分析,结果表明:以55 ℃为界,将14个堆肥样品划分为2个族,族间的相似性仅为13%,说明堆肥过程中常温期(<55 ℃)和高温期(>55 ℃)微生物群落结构差别较大.对优势条带回收测序的结果表明:在升温期,堆肥堆体中检测到H.obtusa和人类排泄物中的细菌;但随着温度的升高,具有纤维素降解功能的嗜热微生物Clostridium thermocellum成为堆肥高温期的优势细菌;当堆体温度小于55 ℃时出现了大量的未培养微生物.