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- ItemBiogas crops grown in energy crop rotations: Linking chemical composition and methane production characteristics(Amsterdam : Elsevier, 2016) Herrmann, Christiane; Idler, Christine; Heiermann, MonikaMethane production characteristics and chemical composition of 405 silages from 43 different crop species were examined using uniform laboratory methods, with the aim to characterise a wide range of crop feedstocks from energy crop rotations and to identify main parameters that influence biomass quality for biogas production. Methane formation was analysed from chopped and over 90 days ensiled crop biomass in batch anaerobic digestion tests without further pre-treatment. Lignin content of crop biomass was found to be the most significant explanatory variable for specific methane yields while the methane content and methane production rates were mainly affected by the content of nitrogen-free extracts and neutral detergent fibre, respectively. The accumulation of butyric acid and alcohols during the ensiling process had significant impact on specific methane yields and methane contents of crop silages. It is proposed that products of silage fermentation should be considered when evaluating crop silages for biogas production.
- ItemEffect of Liquid Hot Water Pretreatment on Hydrolysates Composition and Methane Yield of Rice Processing Residue(Basel : MDPI, 2021) López González, Lisbet Mailin; Heiermann, MonikaLignocellulosic rice processing residue was pretreated in liquid hot water (LHW) at three different temperatures (140, 160, and 180 °C) and two pretreatment times (10 and 20 min) in order to assess its effects on hydrolysates composition, matrix structural changes and methane yield. The concentrations of acetic acid, 5-hydroxymethylfurfural and furfural increased with pretreatment severity (log Ro). The maximum methane yield (276 L kg−1 VS) was achieved under pretreatment conditions of 180 °C for 20 min, with a 63% increase compared to untreated biomass. Structural changes resulted in a slight removal of silica on the upper portion of rice husks, visible predominantly at maximum severity. However, the outer epidermis was kept well organized. The results indicate, at severities 2.48 ≤ log Ro ≤ 3.66, a significant potential for the use of LHW to improve methane production from rice processing residue.
- ItemUnraveling the microbiome of a thermophilic biogas plant by metagenome and metatranscriptome analysis complemented by characterization of bacterial and archaeal isolates(London : BioMed Central, 2016) Maus, Irena; Koeck, Daniela E.; Cibis, Katharina G.; Hahnke, Sarah; Kim, Yong S.; Langer, Thomas; Kreube, Jana; Erhard, Marcel; Bremges, Andreas; Off, Sandra; Stolze, Ivonne; Jaenicke, Sebastian; Goesmann, Alexander; Sczyrba, Alexander; Scherer, Paul; König, Helmut; Schwarz, Wolfgang H.; Zverlov, Vladimir V.; Liebl, Wolfgang; Pühler, Alfred; Schlüter, Andreas; Klocke, MichaelOne of the most promising technologies to sustainably produce energy and to mitigate greenhouse gas emissions from combustion of fossil energy carriers is the anaerobic digestion and biomethanation of organic raw material and waste towards biogas by highly diverse microbial consortia. In this context, the microbial systems ecology of thermophilic industrial-scale biogas plants is poorly understood.
- ItemGenomics and prevalence of bacterial and archaeal isolates from biogas-producing microbiomes(London : BioMed Central, 2017-11-13) Maus, Irena; Bremges, Andreas; Stolze, Yvonne; Hahnke, Sarah; Cibis, Katharina G.; Koeck, Daniela E.; Kim, Yong S.; Kreubel, Jana; Hassa, Julia; Wibberg, Daniel; Weimann, Aaron; Off, Sandra; Stantscheff, Robbin; Zverlov, Vladimir V.; Schwarz, Wolfgang H.; König, Helmut; Liebl, Wolfgang; Scherer, Paul; McHardy, Alice C.; Sczyrba, Alexander; Klocke, Michael; Pühler, Alfred; Schlüter, AndreasBackground: To elucidate biogas microbial communities and processes, the application of high-throughput DNA analysis approaches is becoming increasingly important. Unfortunately, generated data can only partialy be interpreted rudimentary since databases lack reference sequences. Results: Novel cellulolytic, hydrolytic, and acidogenic/acetogenic Bacteria as well as methanogenic Archaea originating from different anaerobic digestion communities were analyzed on the genomic level to assess their role in biomass decomposition and biogas production. Some of the analyzed bacterial strains were recently described as new species and even genera, namely Herbinix hemicellulosilytica T3/55T, Herbinix luporum SD1DT, Clostridium bornimense M2/40T, Proteiniphilum saccharofermentans M3/6T, Fermentimonas caenicola ING2-E5BT, and Petrimonas mucosa ING2-E5AT. High-throughput genome sequencing of 22 anaerobic digestion isolates enabled functional genome interpretation, metabolic reconstruction, and prediction of microbial traits regarding their abilities to utilize complex bio-polymers and to perform specific fermentation pathways. To determine the prevalence of the isolates included in this study in different biogas systems, corresponding metagenome fragment mappings were done. Methanoculleus bourgensis was found to be abundant in three mesophilic biogas plants studied and slightly less abundant in a thermophilic biogas plant, whereas Defluviitoga tunisiensis was only prominent in the thermophilic system. Moreover, several of the analyzed species were clearly detectable in the mesophilic biogas plants, but appeared to be only moderately abundant. Among the species for which genome sequence information was publicly available prior to this study, only the species Amphibacillus xylanus, Clostridium clariflavum, and Lactobacillus acidophilus are of importance for the biogas microbiomes analyzed, but did not reach the level of abundance as determined for M. bourgensis and D. tunisiensis. Conclusions: Isolation of key anaerobic digestion microorganisms and their functional interpretation was achieved by application of elaborated cultivation techniques and subsequent genome analyses. New isolates and their genome information extend the repository covering anaerobic digestion community members. © 2017 The Author(s).
- ItemMetaproteome analysis reveals that syntrophy, competition, and phage-host interaction shape microbial communities in biogas plants(London : Biomed Central, 2019) Heyer, R.; Schallert, K.; Siewert, C.; Kohrs, F.; Greve, J.; Maus, I.; Klang, J.; Klocke, M.; Heiermann, M.; Hoffmann, M.; Püttker, S.; Calusinska, M.; Zoun, R.; Saake, G.; Benndorf, D.; Reichl, U.Background: In biogas plants, complex microbial communities produce methane and carbon dioxide by anaerobic digestion of biomass. For the characterization of the microbial functional networks, samples of 11 reactors were analyzed using a high-resolution metaproteomics pipeline. Results: Examined methanogenesis archaeal communities were either mixotrophic or strictly hydrogenotrophic in syntrophy with bacterial acetate oxidizers. Mapping of identified metaproteins with process steps described by the Anaerobic Digestion Model 1 confirmed its main assumptions and also proposed some extensions such as syntrophic acetate oxidation or fermentation of alcohols. Results indicate that the microbial communities were shaped by syntrophy as well as competition and phage-host interactions causing cell lysis. For the families Bacillaceae, Enterobacteriaceae, and Clostridiaceae, the number of phages exceeded up to 20-fold the number of host cells. Conclusion: Phage-induced cell lysis might slow down the conversion of substrates to biogas, though, it could support the growth of auxotrophic microbes by cycling of nutrients. © 2019 The Author(s).
- ItemImproving aerobic stability and biogas production of maize silage using silage additives(Amsterdam : Elsevier, 2015) Herrmann, Christiane; Idler, Christine; Heiermann, MonikaThe effects of air stress during storage, exposure to air at feed-out, and treatment with silage additives to enhance aerobic stability on methane production from maize silage were investigated at laboratory scale. Up to 17% of the methane potential of maize without additive was lost during seven days exposure to air on feed-out. Air stress during storage reduced aerobic stability and further increased methane losses. A chemical additive containing salts of benzoate and propionate, and inoculants containing heterofermentative lactic acid bacteria were effective to increase aerobic stability and resulted in up to 29% higher methane yields after exposure to air. Exclusion of air to the best possible extent and high aerobic stabilities should be primary objectives when ensiling biogas feedstocks.
- ItemProcess disturbances in agricultural biogas production—causes, mechanisms and effects on the biogas microbiome: A review(Basel : MDPI AG, 2019) Theuerl, S.; Klang, J.; Prochnow, A.Disturbances of the anaerobic digestion process reduce the economic and environmental performance of biogas systems. A better understanding of the highly complex process is of crucial importance in order to avoid disturbances. This review defines process disturbances as significant changes in the functionality within the microbial community leading to unacceptable and severe decreases in biogas production and requiring an active counteraction to be overcome. The main types of process disturbances in agricultural biogas production are classified as unfavorable process temperatures, fluctuations in the availability of macro- and micronutrients (feedstock variability), overload of the microbial degradation potential, process-related accumulation of inhibiting metabolites such as hydrogen (H 2 ), ammonium/ammonia (NH 4 + /NH 3 ) or hydrogen sulphide (H 2 S) and inhibition by other organic and inorganic toxicants. Causes, mechanisms and effects on the biogas microbiome are discussed. The need for a knowledge-based microbiome management to ensure a stable and efficient production of biogas with low susceptibility to disturbances is derived and an outlook on potential future process monitoring and control by means of microbial indicators is provided.
- ItemThe future agricultural biogas plant in Germany: A vision(Basel : MDPI AG, 2019) Theuerl, S.; Herrmann, C.; Heiermann, M.; Grundmann, P.; Landwehr, N.; Kreidenweis, U.; Prochnow, A.After nearly two decades of subsidized and energy crop-oriented development, agricultural biogas production in Germany is standing at a crossroads. Fundamental challenges need to be met. In this article we sketch a vision of a future agricultural biogas plant that is an integral part of the circular bioeconomy and works mainly on the base of residues. It is flexible with regard to feedstocks, digester operation, microbial communities and biogas output. It is modular in design and its operation is knowledge-based, information-driven and largely automated. It will be competitive with fossil energies and other renewable energies, profitable for farmers and plant operators and favorable for the national economy. In this paper we discuss the required contribution of research to achieve these aims.
- ItemThe role of petrimonas mucosa ING2-E5at in mesophilic biogas reactor systems as deduced from multiomics analyses(Basel : MDPI AG, 2020) Maus, Irena; Tubbesing, Tom; Wibberg, Daniel; Heyer, Robert; Hassa, Julia; Tomazetto, Geizecler; Huang, Liren; Bunk, Boyke; Spröer, Cathrin; Benndorf, Dirk; Zverlov, Vladimir; Pühler, Alfred; Klocke, Michael; Sczyrba, Alexander; Schlüter, AndreasMembers of the genera Proteiniphilum and Petrimonas were speculated to represent indicators reflecting process instability within anaerobic digestion (AD) microbiomes. Therefore, Petrimonas mucosa ING2-E5AT was isolated from a biogas reactor sample and sequenced on the PacBio RSII and Illumina MiSeq sequencers. Phylogenetic classification positioned the strain ING2-E5AT in close proximity to Fermentimonas and Proteiniphilum species (family Dysgonomonadaceae). ING2-E5AT encodes a number of genes for glycosyl-hydrolyses (GH) which are organized in Polysaccharide Utilization Loci (PUL) comprising tandem susCD-like genes for a TonB-dependent outer-membrane transporter and a cell surface glycan-binding protein. Different GHs encoded in PUL are involved in pectin degradation, reflecting a pronounced specialization of the ING2-E5AT PUL systems regarding the decomposition of this polysaccharide. Genes encoding enzymes participating in amino acids fermentation were also identified. Fragment recruitments with the ING2-E5AT genome as a template and publicly available metagenomes of AD microbiomes revealed that Petrimonas species are present in 146 out of 257 datasets supporting their importance in AD microbiomes. Metatranscriptome analyses of AD microbiomes uncovered active sugar and amino acid fermentation pathways for Petrimonas species. Likewise, screening of metaproteome datasets demonstrated expression of the Petrimonas PUL-specific component SusC providing further evidence that PUL play a central role for the lifestyle of Petrimonas species. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.
- ItemImpact of energy crop rotation design on multiple aspects of resource efficiency(Hoboken, NJ : Wiley, 2016) Peter, Christiane; Glemnitz, Michael; Winter, Katharina; Kornatz, Peter; Müller, Janine; Heiermann, Monika; Aurbacher, JoachimBiogas production can cause environmental problems due to a biased alignment of one energy crop used as a feedstock, e.g., maize in Germany. Diversification of crop rotations and resource-efficient management can be the key to sustainable crop management. Four crop rotations on eight sites across Germany were evaluated in terms of their resource efficiency (area use, energy, and economic efficiency) to derive options. Analysis revealed high variation in all indicators under review, with a high variance explanation by the interaction between crop rotation and regional characteristics. Furthermore, results indicate that high area-specific methane yields do not equate to high energy efficiency. Crop management adaptation is a useful tool for optimizing resource efficiency.