Department of Food Environmental and Nutritional Sciences (DEFENS), University of Milan, Celoria 2, 20133 Milan, Italy.
Water Res. 2013 Apr 15;47(6):1983-95. doi: 10.1016/j.watres.2013.01.007. Epub 2013 Jan 18.
The microbial community of a thermophilic two-stage process was monitored during two-months operation and compared to a conventional single-stage process. Qualitative and quantitative microbial dynamics were analysed by Denaturing Gradient Gel Electrophoresis (DGGE) and real-time PCR techniques, respectively. The bacterial community was dominated by heat-shock resistant, spore-forming clostridia in the two-stage process, whereas a more diverse and dynamic community (Firmicutes, Bacteroidetes, Synergistes) was observed in the single-stage process. A significant evolution of bacterial community occurred over time in the acidogenic phase of the two-phase process with the selection of few dominant species associated to stable hydrogen production. The archaeal community, dominated by the acetoclastic Methanosarcinales in both methanogen reactors, showed a significant diversity change in the single-stage process after a period of adaptation to the feeding conditions, compared to a constant stability in the methanogenic reactor of the two-stage process. The more diverse and dynamic bacterial and archaeal community of single-stage process compared to the two-stage process accounted for the best degradation activity, and consequently the best performance, in this reactor. The microbiological perspective proved a useful tool for a better understanding and comparison of anaerobic digestion processes.
采用变性梯度凝胶电泳（DGGE）和实时 PCR 技术，分别对嗜热两段式工艺和传统单相工艺在两个月运行过程中的微生物群落进行了定性和定量分析。两段式工艺中的细菌群落以耐热、产孢子的梭菌为主，而单相工艺中则观察到更具多样性和动态性的群落（厚壁菌门、拟杆菌门、互营菌科）。在两相工艺的产酸相中，随着与稳定产氢相关的少数优势种的选择，细菌群落随时间发生了显著的进化。在单相工艺中，在适应进料条件一段时间后，产甲烷反应器中的优势产乙酸古菌（acetoclastic Methanosarcinales）的古菌群落发生了显著的多样性变化，而两段式工艺的产甲烷反应器则保持稳定。与两段式工艺相比，单相工艺中具有更多样性和动态性的细菌和古菌群落，其降解活性更好，因此该反应器的性能也更好。微生物学视角为更好地理解和比较厌氧消化工艺提供了有用的工具。
