title: Long-term monitoring reveals stable and remarkably similar microbial communities in parallel full-scale biogas reactors digesting energy crops.
abstract: Biogas is an important renewable energy carrier. It is a product of stepwise anaerobic degradation of organic materials by highly diverse microbial communities forming complex interlinking metabolic networks. Knowledge about the microbial background of long-term stable process performance in full-scale reactors is crucial for rationally improving the efficiency and reliability of biogas plants. To generate such knowledge, in the present study three parallel mesophilic full-scale reactors fed exclusively with energy crops were sampled weekly over one year. Physicochemical process parameters were determined and the microbial communities were analysed by terminal restriction fragment length polymorphism (T-RFLP) fingerprinting and 454-amplicon sequencing. For investigating the methanogenic community, a high-resolution T-RFLP approach based on the mcrA gene was developed by selecting restriction enzymes with improved taxonomic resolution compared to previous studies. Interestingly, no Methanosarcina-related generalists, but rather specialized hydrogenotrophic and acetoclastic methanogenic taxa were detected. In general, the microbial communities in the non-connected reactors were remarkably stable and highly similar indicating that identical environmental and process parameters resulted in identical microbial assemblages and dynamics. Practical implications such as flexible operation schemes comprising controlled variations of process parameters for an efficient microbial resource management under fluctuating process conditions are discussed.
authors.affiliation: UFZ - Helmholtz Centre for Environmental Research GmbH, Department of Environmental Microbiology, Permoserstr. 15, 04318 Leipzig, Germany.
authors.forename: Rico
authors.initials: R
authors.lastname: Lucas
authors.affiliation: UFZ - Helmholtz Centre for Environmental Research GmbH, Department of Environmental Microbiology, Permoserstr. 15, 04318 Leipzig, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Kuchenbuch
authors.affiliation: Stockholm Resilience Centre, Stockholm University, Kräftriket 2B, 10691 Stockholm, Sweden.
authors.forename: Ingo
authors.initials: I
authors.lastname: Fetzer
authors.affiliation: UFZ - Helmholtz Centre for Environmental Research GmbH, Department of Environmental Microbiology, Permoserstr. 15, 04318 Leipzig, Germany German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, D-04103 Leipzig, Germany.
authors.forename: Hauke
authors.initials: H
authors.lastname: Harms
authors.affiliation: UFZ - Helmholtz Centre for Environmental Research GmbH, Department of Environmental Microbiology, Permoserstr. 15, 04318 Leipzig, Germany sabine.kleinsteuber@ufz.de.
authors.forename: Sabine
authors.initials: S
authors.lastname: Kleinsteuber
mesh_terms: D039903:Actinobacteria / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D056804:Biofuels / Q000382:microbiology*; D019149:Bioreactors / Q000382:microbiology*; D041862:Chloroflexi / Q000235:genetics / Q000378:metabolism; D003013:Clostridium / Q000235:genetics / Q000378:metabolism; D018556:Crops, Agricultural / Q000378:metabolism* / Q000382:microbiology; D004262:DNA Restriction Enzymes / Q000235:genetics; D019641:DNA, Archaeal / Q000235:genetics; D019605:Euryarchaeota / Q000145:classification* / Q000235:genetics / Q000378:metabolism; D007778:Lactobacillus / Q000235:genetics / Q000378:metabolism; D064307:Microbiota / Q000502:physiology; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D015203:Reproducibility of Results; D017422:Sequence Analysis, DNA; D013291:Streptococcus / Q000235:genetics / Q000378:metabolism; D003313:Zea mays / Q000378:metabolism* / Q000382:microbiology
chemical_list: D056804:Biofuels; D019641:DNA, Archaeal; D004262:DNA Restriction Enzymes; C060629:endodeoxyribonuclease McrA
keywords: T-RFLP; amplicon pyrosequencing; anaerobic digestion; community assemblage; maize silage; mcrA