Civil & Environmental Engineering, Colorado State University, Ft. Collins, CO 80532, USA; Geological Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
Waste Manag. 2013 Oct;33(10):1982-92. doi: 10.1016/j.wasman.2012.12.013. Epub 2013 Jan 12.
The objectives of this study were to characterize development of bacterial and archaeal populations during biodegradation of municipal solid waste (MSW) and to link specific methanogens to methane generation. Experiments were conducted in three 0.61-m-diameter by 0.90-m-tall laboratory reactors to simulate MSW bioreactor landfills. Pyrosequencing of 16S rRNA genes was used to characterize microbial communities in both leachate and solid waste. Microbial assemblages in effluent leachate were similar between reactors during peak methane generation. Specific groups within the Bacteroidetes and Thermatogae phyla were present in all samples and were particularly abundant during peak methane generation. Microbial communities were not similar in leachate and solid fractions assayed at the end of reactor operation; solid waste contained a more abundant bacterial community of cellulose-degrading organisms (e.g., Firmicutes). Specific methanogen populations were assessed using quantitative polymerase chain reaction. Methanomicrobiales, Methanosarcinaceae, and Methanobacteriales were the predominant methanogens in all reactors, with Methanomicrobiales consistently the most abundant. Methanogen growth phases coincided with accelerated methane production, and cumulative methane yield increased with increasing total methanogen abundance. The difference in methanogen populations and corresponding methane yield is attributed to different initial cellulose and hemicellulose contents of the MSW. Higher initial cellulose and hemicellulose contents supported growth of larger methanogen populations that resulted in higher methane yield.
本研究的目的是描述城市固体废物（MSW）生物降解过程中细菌和古菌种群的发展，并将特定的产甲烷菌与甲烷生成联系起来。实验在三个直径为 0.61 米、高为 0.90 米的实验室反应堆中进行，以模拟 MSW 生物反应器填埋场。16S rRNA 基因的焦磷酸测序用于描述渗滤液和固体废物中的微生物群落。在甲烷生成高峰期，所有反应器中的渗滤液中微生物群落都相似。厚壁菌门和热袍菌门内的特定群体存在于所有样品中，在甲烷生成高峰期尤为丰富。在反应器运行结束时检测的渗滤液和固体部分的微生物群落并不相似；固体废物中含有更丰富的纤维素降解生物的细菌群落（例如，Firmicutes）。使用定量聚合酶链反应评估特定的产甲烷菌种群。所有反应器中主要的产甲烷菌为甲烷微菌目、甲烷八叠球菌科和甲烷杆菌目，其中甲烷微菌目始终最为丰富。产甲烷菌的生长阶段与加速的甲烷生成相吻合，累积甲烷产量随总产甲烷菌丰度的增加而增加。产甲烷菌种群和相应的甲烷产量的差异归因于 MSW 中初始纤维素和半纤维素含量的不同。较高的初始纤维素和半纤维素含量支持更大的产甲烷菌种群的生长，从而产生更高的甲烷产量。
