title: Microbial community structure and dynamics in two-stage vs single-stage thermophilic anaerobic digestion of mixed swine slurry and market bio-waste.
abstract: 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.
authors: Department of Food Environmental and Nutritional Sciences (DEFENS), University of Milan, Celoria 2, 20133 Milan, Italy.
authors: Giuseppe
authors: G
authors: Merlino
authors: Aurora
authors: A
authors: Rizzi
authors: Andrea
authors: A
authors: Schievano
authors: Alberto
authors: A
authors: Tenca
authors: Barbara
authors: B
authors: Scaglia
authors: Roberto
authors: R
authors: Oberti
authors: Fabrizio
authors: F
authors: Adani
authors: Daniele
authors: D
authors: Daffonchio
mesh_terms: D061271:Acidobacteria / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism; D000822:Animal Husbandry / Q000191:economics; D000818:Animals; D019843:Archaeal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019149:Bioreactors / Q000191:economics / Q000382:microbiology*; D003013:Clostridium / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism; D005285:Fermentation; D006089:Gram-Negative Anaerobic Bacteria / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D006094:Gram-Positive Bacteria / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D006358:Hot Temperature; D007220:Industrial Waste / Q000032:analysis* / Q000191:economics; D007558:Italy; D008372:Manure / Q000382:microbiology*; D008462:Meat-Packing Industry / Q000191:economics; D008697:Methane / Q000378:metabolism; D019640:Methanosarcinales / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D056265:Microbial Interactions; D010802:Phylogeny; D034421:Sus scrofa / Q000382:microbiology*
chemical_list: D019843:Archaeal Proteins; D001426:Bacterial Proteins; D007220:Industrial Waste; D008372:Manure; D008697:Methane