@misc{OttoAbendrothDornack, author = {Otto, Pascal and Abendroth, Christian and Dornack, Christina}, title = {Designer-Mikrobiome f{\"u}r den Biogassektor}, series = {M{\"u}ll und Abfall}, volume = {54}, journal = {M{\"u}ll und Abfall}, number = {05}, issn = {1863-9763}, doi = {10.37307/j.1863-9763.2022.05.05}, pages = {243 -- 247}, abstract = {Das Institut f{\"u}r Abfall- und Kreislaufwirtschaft (IAK) der TU Dresden ist am von der Europ{\"a}ischen Union im Rahmen des H2020-Programms gef{\"o}rderten Projekts "Micro4Biogas" beteiligt. Ziel des Projektes ist es, zur Unterst{\"u}tzung und Modernisierung des Biogassektors in den EU-L{\"a}ndern beizutragen. Im Mittelpunkt stehen die Untersuchung der anaeroben Verg{\"a}rung und des Mikrobioms, welche trotz jahrzehntelanger Forschung nicht ausreichend entschl{\"u}sselt sind. Obwohl das Wissen {\"u}ber die beteiligten Mikroorganismen zunimmt, wird das Mikrobiom nach wie vor als "Black Box" betrachtet. Im Rahmen von Micro4Biogas erfolgt die Charakterisierung nat{\"u}rlicher mikrobieller Gemeinschaften sowie die Erforschung neuer synthetischer mikrobieller Gemeinschaften. Darauf aufbauend erfolgt die Entwicklung von Strategien zur gezielten Beeinflussung des Mikrobioms (Bioaugmentation), die dazu dienen, den Prozess robuster, schneller, produktiver und standardisierter zu gestalten. Das bestehende und generierte Fachwissen wird in einer frei verf{\"u}gbaren Roadmap zusammengefasst. Die Roadmap soll zudem Leitlinien und Handlungsempfehlungen f{\"u}r Industrie und Politik zur nachhaltigen und optimierten Produktion von Biogas enthalten.}, language = {de} } @misc{OttoAbendroth, author = {Otto, Pascal and Abendroth, Christian}, title = {The European Biogas Landscape: One of the most comprehensive studies on the biogas sector}, address = {Leipzig}, abstract = {At the BIOENERGY DOC2022 (5th doctoral colloquium bioenergy), results from the currently running EU project Micro4Biogas were presented (https://micro4biogas.eu/). The presented poster describes the sampling of more than 70 samples from a large number of biogas plants in Germany and the Netherlands. Samples were analysed chemically and taxonomically. A comprehensive dataset was developed for the technical description of the respective plants. In the next step, a holistic, multivariate analysis of the collected data sets is planned.}, language = {en} } @misc{AbendrothDornackNefigmannetal., author = {Abendroth, Christian and Dornack, Christina and Nefigmann, Sven and Otto, Pascal}, title = {Mikroskopische Helden der Biogasbranche}, series = {Tagungsband zum 20. Dialog Abfallwirtschaft und zum 16. Rostocker Bioenergieforum}, journal = {Tagungsband zum 20. Dialog Abfallwirtschaft und zum 16. Rostocker Bioenergieforum}, editor = {Nelles, Michael}, address = {Rostock}, isbn = {978-3-86009-535-5}, doi = {10.18453/rosdok_id00003615}, pages = {233 -- 241}, abstract = {Das Streben nach umweltfreundlicher Energie und Wertstoffen hat in den letzten Jahren, gest{\"a}rkt durch Wirtschaft und Politik, den Drang nach Innovation erheblich angeregt. Dieser Entwicklungsdrang findet sich in vielen Bereichen wieder, unter anderem in der Bio{\"o}konomie und hier auch bei Biogasanlagen. Das Schlagwort „Mikrobiom" ist im medizinischen Bereich bereits weit verbreitet und wird im popul{\"a}rwissenschaftlichen Bereich in zahlreichen B{\"u}chern diskutiert. Dies unterstreicht das große gesellschaftliche Interesse an diesem Thema. Neben diesen Erkenntnissen gewinnt das Mikrobiom im Bereich der Bioenergien zunehmend an Bedeutung. In den letzten Jahren sind in hochrangigen, internationalen Fachjournalen zahlreichen Artikel erschienen, welche aufzeigen, dass Biogasanlagen wahre Superhelden unter den Mikroorganismen beherbergen. Die hohe Diversit{\"a}t wurde bereits in zahlreichen Publikationen diskutiert. Trotz dessen wird das Mikrobiom als „Blackbox" betrachtet. Wissenschaftler weltweit versuchen diese Blackbox aufzul{\"o}sen und hierbei traten einige {\"U}berraschungen auf. Dieses neue Wissen k{\"o}nnte den Grundstein f{\"u}r neue Konzepte der Prozesssteuerung legen. Ziel der vorliegenden Arbeit ist in diesem Zusammenhang eine Kurz{\"u}bersicht {\"u}ber mikrobielle Innovation im Zusammenhang mit anaeroben Mikrobiomen.}, language = {de} } @misc{Abendroth, author = {Abendroth, Christian}, title = {Zirkul{\"a}re Mikrobiome f{\"u}r Recycling- und R{\"u}ckgewinnungsanwendungen}, series = {Werkstoffe in der Fertigung}, journal = {Werkstoffe in der Fertigung}, number = {1}, issn = {0939-2629}, pages = {27 -- 28}, abstract = {Der Artikel stellt das Fachgebiet der Kreislaufwirtschaft an der BTU vor. Forschungsthemen des Fachgebietes werden kurz erl{\"a}utert. Diese umfassen Biolaugung zur Behandlung von Leiterplatten, anaerobe Fermentation als Multiproduktplattform, Power2Gas Prozesse sowie das Verst{\"a}ndnis mikrobieller Gemeinschaften mit Bedeutung f{\"u}r die Kreislaufwirtschaft.}, language = {de} } @misc{JansenAbendroth, author = {Jansen, Nils and Abendroth, Christian}, title = {Unveiling the Biochar Potential: Lowering Greenhouse Gas Emissions across the Biogas Supply Chain}, series = {Kreislauf und Ressourcenwirtschaft : 13.Wissenschaftskongress : am 15. und 16. Februar 2024 an der Technischen Universit{\"a}t Wien, Tagungsband}, journal = {Kreislauf und Ressourcenwirtschaft : 13.Wissenschaftskongress : am 15. und 16. Februar 2024 an der Technischen Universit{\"a}t Wien, Tagungsband}, editor = {Bockreis, Anke and Faulstich, Martin and Flamme, Sabine and Kranert, Martin and Mocker, Mario and Nelles, Michael and Quicker, Peter and Rettenberger, Gerhard and Rotter, Vera Susanne}, publisher = {Innsbruck university press}, address = {Innsbruck}, isbn = {978-3-99106-120-5}, doi = {10.15203/99106-120-5}, pages = {279 -- 286}, abstract = {The carbon-rich material known as biochar is the product of pyrolysis - a thermochemical conversion of biomass in the absence of oxygen. Given its characteristics, including long-term stability and sorption capacity, biochar has received increasing attention as a promising tool for addressing climate change and enhancing the production of biogas. This work combines both functions by examining, through different application scenarios, the potential role of biochar in mitigating greenhouse gas (GHG) emissions across the biogas supply chain. The wood-derived and high pyrolyzed biochar CarboFerm® was used as an example biochar for application in four different scenarios: (1) Application to soil without fertilizer, (2) application to soil with fertilizer, (3) application to biogas fermenter, (4) application to digestate treatment. The GHG mitigation was calculated by applying the methodology of the Renewable Energy Directive II (RED II). The scenario comparison resulted in GHG mitigation effectiveness of 0.03, 0.01, 0.06, and 0.03 g CO2eq / MJ biogas / t biochar, respectively. Thus, this study recommends using biochar in biogas fermenters and subsequently applying the biochar-enriched digestate to agricultural soil to reduce GHG emissions from biogas production. Furthermore, it is suggested that the mitigation potential of biochar may not be fully recognized in the RED, potentially resulting in an underestimation of its effectiveness.}, language = {en} } @misc{AlipoursarbaniAbendroth, author = {Alipoursarbani, Mozhdeh and Abendroth, Christian}, title = {Aerobic Digestate Reactivation of Anaerobically Digested Sewage Sludge - A Micro Review}, series = {Kreislauf und Ressourcenwirtschaft : 13.Wissenschaftskongress : am 15. und 16. Februar 2024 an der Technischen Universit{\"a}t Wien}, journal = {Kreislauf und Ressourcenwirtschaft : 13.Wissenschaftskongress : am 15. und 16. Februar 2024 an der Technischen Universit{\"a}t Wien}, editor = {Bockreis, Anke and Faulstich, Martin and Flamme, Sabine and Kranert, Martin and Mocker, Mario and Nelles, Michael and Quicker, Peter and Rettenberger, Gerhard and Rotter, Vera Susanne}, publisher = {Innsbruck university press}, address = {Innsbruck}, isbn = {978-3-99106-120-5}, doi = {10.15203/99106-120-5}, pages = {177 -- 180}, abstract = {The authors of the present work summarize their recently published article "Microbiome Characterization after Aerobic Digestate Reactivation of Anaerobically Digested Sewage Sludge" from Otto et al. (2023). This article presents the outcomes of a municipal-scale demonstrator plant implementing a recently patented process for improved sludge degradation within a municipal sewage treatment system. The study focused on a 1500 m³ sewage sludge digester, where an intermediate aerobic sewage sludge reactivation stage was introduced. This reactivation resulted in a 55\% increase in biogas production and a 25\% reduction in residual solids. For the residual NH4 in the liquid phase of the sewage sludge, the process achieved NH4-N removal rates exceeding 90\%. To gain insights into the microbial community dynamics, 16S rRNA gene amplicon high-throughput sequencing was employed on the reactivated digestate. The analysis revealed a reduced population of methane-forming archaea compared to the primary digester, along with the detection of multiple ammonium-oxidizing bacteria. Notably, genera within the Chitinophagaceae family, comprising up to 18.8\% of DNA sequences, were prevalent, alongside a small presence of Candidatus nitrosoglobus (<0.3\%). The study highlights an economically viable approach for efficient nitrogen removal from sewage sludge while simultaneously increasing biogas yields and reducing potential pathogens in the residual material.}, language = {en} } @misc{WitkabelAbendroth, author = {Witkabel, Philipp and Abendroth, Christian}, title = {A systematic literature review of microbial anammox consortia in UASB/ EGSB-reactors}, series = {Chemosphere}, volume = {367}, journal = {Chemosphere}, publisher = {Elsevier BV}, issn = {0045-6535}, doi = {10.1016/j.chemosphere.2024.143630}, pages = {17}, abstract = {Anaerobic ammonium oxidation (anammox) poses an emerging research field as it can outstand previous processes of biological wastewater treatment in terms of efficiency and costs. Anammox bacteria have the ability to metabolise NH4+ and NO2- to produce N2 under anaerobic conditions. Despite numerous studies, there is a lack of research on the co-occurrence and interrelationship of the predominant microbes that inhabit anammox-related processes. This systematic literature review follows the PSALSAR approach to assess metagenomic data on anammox bacteria and functional microbes in upstream reactors. Essential information on the physiology, metabolic pathways and inhibitory effects of anammox bacteria are reviewed and functional bacteria such as ammonia-oxidising bacteria (AOB), nitrite-oxidising bacteria (NOB), ammonia-oxidising Archaea (AOA) and denitrifying bacteria are identified. Candidatus Kuenenia and Candidatus Brocadia were the most frequently sequenced genera in the observed literature. Pseudomonadota, Chloroflexota and Bacteroidota were prevalent regardless of crucial operational parameters and configurations that affect the microbial community. Interrelationship analysis revealed a positive association between the versatility of a phylum's metabolism and its presence in the observed wastewater treatment literature. Several groups, such as Calditrichota, Myxococcota and Deinococcota are highly underrepresented, a finding that should be investigated in more detail. No evidence was found to suggest that high anammox ratios are correlated with high nitrogen removal efficiencies, as some studies found high efficiency despite low anammox abundance (<1\%).}, language = {en} } @misc{OttoPucholRoyoOrtegaLegarretaetal., author = {Otto, Pascal and Puchol-Royo, Roser and Ortega-Legarreta, Asier and Tanner, Kristie and Tideman, Jeroen and De Vries, Sjoerd-Jan and Pascual, Javier and Porcar, Manuel and Latorre-P{\´e}rez, Adriel and Abendroth, Christian}, title = {Multivariate comparison of taxonomic, chemical and operational data from 80 different full-scale anaerobic digester-related systems}, series = {Biotechnology for Biofuels and Bioproducts}, volume = {17}, journal = {Biotechnology for Biofuels and Bioproducts}, doi = {10.1186/s13068-024-02525-1}, pages = {1 -- 17}, abstract = {Background: The holistic characterization of different microbiomes in anaerobic digestion (AD) systems can contribute to a better understanding of these systems and provide starting points for bioengineering. The present study investigates the microbiome of 80 European full-scale AD systems. Operational, chemical and taxonomic data were thoroughly collected, analysed and correlated to identify the main drivers of AD processes. Results: The present study describes chemical and operational parameters for a broad spectrum of different AD systems. With this data, Spearman correlation and differential abundance analyses were applied to narrow down the role of the individual microorganisms detected. The authors succeeded in further limiting the number of microorganisms in the core microbiome for a broad range of AD systems. Based on 16S rRNA gene amplicon sequencing, MBA03, Proteiniphilum, a member of the family Dethiobacteraceae, the genus Caldicoprobacter and the methanogen Methanosarcina were the most prevalent and abundant organisms identified in all digesters analysed. High ratios for Methanoculleus are often described for agricultural co-digesters. Therefore, it is remarkable that Methanosarcina was surprisingly high in several digesters reaching ratios up to 47.2\%. The various statistical analyses revealed that the microorganisms grouped according to different patterns. A purely taxonomic correlation enabled a distinction between an acetoclastic cluster and a hydrogenotrophic one. However, in the multivariate analysis with chemical parameters, the main clusters corresponded to hydrolytic and acidogenic microorganisms, with SAOB bacteria being particularly important in the second group. Including operational parameters resulted in digester-type specific grouping of microbes. Those with separate acidification stood out among the many reactor types due to their unexpected behaviour. Despite maximizing the organic loading rate in the hydrolytic pretreatments, these stages turned into extremely robust methane production units. Conclusions: From 80 different AD systems, one of the most holistic data sets is provided. A very distinct formation of microbial clusters was discovered, depending on whether taxonomic, chemical or operational parameters were combined. The microorganisms in the individual clusters were strongly dependent on the respective reference parameters.}, language = {en} } @misc{OttoAbendroth, author = {Otto, Pascal and Abendroth, Christian}, title = {Neue Bakterienordnung entdeckt}, series = {Biogas Journal}, volume = {2024}, journal = {Biogas Journal}, number = {2}, issn = {1619-8913}, pages = {96 -- 99}, abstract = {Wissenschaftler*innen des europ{\"a}ischen Forschungsprojektes Micro4Biogas haben eine neue taxonomische Ordnung von Bakterien entdeckt und klassifiziert, die auf die Zersetzung von organischem Material spezialisiert sind und der Schl{\"u}ssel zu einer optimierten Biogasproduktion sein k{\"o}nnten. Die von ihnen als Darwinibacteriales bezeichnete Ordnung ist eine der am h{\"a}ufigsten vorkommenden Bakterien-Ordnungen in Biogasanlagen, wurde aber bisher noch nie wissenschaftlich klassifiziert.}, language = {de} } @misc{VidalVerduTorrentIglesiasetal., author = {Vidal-Verd{\´u}, {\`A}ngela and Torrent, Daniel and Iglesias, Alba and Latorre-P{\´e}rez, Adriel and Abendroth, Christian and Corb{\´i}n-Agust{\´i}, Paola and Peret{\´o}, Juli and Porcar, Manuel}, title = {The highly differentiated gut of Pachnoda marginata hosts sequential microbiomes: microbial ecology and potential applications}, series = {npj Biofilms and Microbiomes}, volume = {10}, journal = {npj Biofilms and Microbiomes}, number = {1}, publisher = {Springer Science and Business Media LLC}, issn = {2055-5008}, doi = {10.1038/s41522-024-00531-7}, pages = {14}, abstract = {Insect gut microbiomes play a crucial role in the insect development and are shaped, among other factors, by the specialized insect diet habits as well as the morphological structure of the gut. Rose chafers (Pachnoda spp.; Coleoptera: Scarabaeidae) have a highly differentiated gut characterized by a pronounced hindgut dilation which resembles a miniaturized rumen. Specifically, the species Pachnoda marginata has not been previously studied in detail in terms of microbial ecology. Here, we show a fine scale study of the highly compartmentalized gut of P. marginata by using amplicon and metagenomic sequencing to shed light on the bacterial, archaeal and fungal communities thriving in each section of the gut. We found a microbial gradient along the gut from aerobic (foregut) to strictly anaerobic communities (hindgut). In addition, we have characterized interesting biological activities and metabolic pathways of gut microbial communities related to cellulose degradation, methane production and sulfate reduction. Taken together, our results reveal the highly diverse microbial community and the potential of P. marginata gut as a source of industrially relevant microbial diversity.}, language = {en} } @misc{BarthWernerOttoetal., author = {Barth, Maximilian and Werner, Magdalena and Otto, Pascal and Richwien, Benjamin and Bahramsari, Samira and Krause, Maximilian and Schwan, Benjamin and Abendroth, Christian}, title = {Microwave-assisted organic acids and green hydrogen production during mixed culture fermentation}, series = {Biotechnology for Biofuels and Bioproducts}, volume = {17}, journal = {Biotechnology for Biofuels and Bioproducts}, number = {1}, publisher = {Springer Science and Business Media LLC}, issn = {2731-3654}, doi = {10.1186/s13068-024-02573-7}, pages = {18}, abstract = {Background: The integration of anaerobic digestion into bio-based industries can create synergies that help render anaerobic digestion self-sustaining. Two-stage digesters with separate acidification stages allow for the production of green hydrogen and short-chain fatty acids, which are promising industrial products. Heat shocks can be used to foster the production of these products, the practical applicability of this treatment is often not addressed sufficiently, and the presented work therefore aims to close this gap. Methods: Batch experiments were conducted in 5 L double-walled tank reactors incubated at 37 °C. Short microwave heat shocks of 25 min duration and exposure times of 5-10 min at 80 °C were performed and compared to oven heat shocks. Pairwise experimental group differences for gas production and chemical parameters were determined using ANOVA and post-hoc tests. High-throughput 16S rRNA gene amplicon sequencing was performed to analyse taxonomic profiles. Results: After heat-shocking the entire seed sludge, the highest hydrogen productivity was observed at a substrate load of 50 g/l with 1.09 mol H2/mol hexose. With 1.01 mol H2/mol hexose, microwave-assisted treatment was not significantly different from oven-based treatments. This study emphasised the better repeatability of heat shocks with microwave-assisted experiments, revealing low variation coefficients averaging 29\%. The pre-treatment with microwaves results in a high predictability and a stronger microbial community shift to Clostridia compared to the treatment with the oven. The pre-treatment of heat shocks supported the formation of butyric acid up to 10.8 g/l on average, with a peak of 24.01 g/l at a butyric/acetic acid ratio of 2.0. Conclusion: The results support the suitability of using heat shock for the entire seed sludge rather than just a small inoculum, making the process more relevant for industrial applications. The performed microwave-based treatment has proven to be a promising alternative to oven-based treatments, which ultimately may facilitate their implementation into industrial systems. This approach becomes economically sustainable with high-temperature heat pumps with a coefficient of performance (COP) of 4.3.}, language = {en} } @misc{OttoAlipoursarbaniTorrentetal., author = {Otto, Pascal and Alipoursarbani, Mozhdeh and Torrent, Daniel and Latorre-P{\´e}rez, Adriel and Paust, Thomas and Albert, Alfred and Abendroth, Christian}, title = {Microbiome Characterization after Aerobic Digestate Reactivation of Anaerobically Digested Sewage Sludge}, series = {Fermentation}, volume = {9}, journal = {Fermentation}, number = {5}, issn = {2311-5637}, doi = {10.3390/fermentation9050471}, abstract = {A demonstrator plant of a recently patented process for improved sludge degradation has been implemented on a municipal scale. In a 1500 m3 sewage sludge digester, an intermediary stage with aerobic sewage sludge reactivation was implemented. This oxic activation increased the biogas yield by up to 55\% with a 25\% reduction of the remaining fermentation residue volume. Furthermore, this process allowed an NH4-N removal of over 90\%. Additionally, 16S rRNA gene amplicon high-throughput sequencing of the reactivated digestate showed a reduced number of methane-forming archaea compared to the main digester. Multiple ammonium-oxidizing bacteria were detected. This includes multiple genera belonging to the family Chitinophagaceae (the highest values reached 18.8\% of the DNA sequences) as well as a small amount of the genus Candidatus nitrosoglobus (<0.3\%). In summary, the process described here provides an economically viable method to eliminate nitrogen from sewage sludge while achieving higher biogas yields and fewer potential pathogens in the residuals.}, language = {en} } @misc{BaptistAbendroth, author = {Baptist, Savannah and Abendroth, Christian}, title = {A systematic review on Carbon Credits}, series = {12. Wissenschaftskongress Abfall- und Ressourcenwirtschaft am 9. und 10. M{\"a}rz 2023, Technischen Universit{\"a}t Hamburg, Tagungsband}, journal = {12. Wissenschaftskongress Abfall- und Ressourcenwirtschaft am 9. und 10. M{\"a}rz 2023, Technischen Universit{\"a}t Hamburg, Tagungsband}, editor = {Bockreis, Anke and Faulstich, Martin and Flamme, Sabine and Kranert, Martin and Mocker, Mario and Nelles, Michael and Quicker, Peter and Rettenberger, Gerhard and Rotter, Vera Susanne}, publisher = {Innsbruck university press}, address = {Innsbruck}, isbn = {978-3-99106-095-6}, doi = {10.15203/99106-095-6}, pages = {179 -- 184}, abstract = {In the last 20 years there has been a growing need for climate mitigation strategies. Starting with the Emission Trading in the Kyoto protocol in 1997, the concept of a carbon market arose. Carbon markets opened an avenue giving countries and businesses an opportunity to trade their emissions as a commodity. The Paris agreement has further acted as an incentive. This led to the introduction of the Carbon Credit. A single carbon credit has been defined as one ton of equivalent CO2, strategies to calculate a baseline for emissions and crediting systems followed. However, currently we still lack a universal method of estimation. There have been efforts by the UNFCCC's clean development mechanism, IPCC and the private sector to develop calculation mechanisms. Despite this, there have been issues in the credibility of these credits. With the Introduction of the non-compliance market there has been a growth of carbon credits in the voluntary markets. This leads to the basic question: Do scientific articles give insight into the existing carbon credit market? The presented study aims to answer the question, using the PSALSA method of systematic review analysis.}, language = {en} } @misc{OttoAbendroth, author = {Otto, Pascal and Abendroth, Christian}, title = {Untersuchung der mikrobiellen Profile von 70 verschiedenen Biogasanlagen und Identifizierung signifikanter technischer und chemischer Einflussgr{\"o}ßen auf das Mikrobiom}, series = {12. Wissenschaftskongress Abfall- und Ressourcenwirtschaft am 9. und 10. M{\"a}rz 2023, Technischen Universit{\"a}t Hamburg, Tagungsband}, journal = {12. Wissenschaftskongress Abfall- und Ressourcenwirtschaft am 9. und 10. M{\"a}rz 2023, Technischen Universit{\"a}t Hamburg, Tagungsband}, editor = {Bockreis, Anke and Faulstich, Martin and Flamme, Sabine and Kranert, Martin and Mocker, Mario and Nelles, Michael and Quicker, Peter and Rettenberger, Gerhard and Rotter, Vera Susanne}, publisher = {Innsbruck university press}, address = {Innsbruck}, isbn = {978-3-99106-095-6}, doi = {10.15203/99106-095-6}, pages = {297 -- 301}, abstract = {Das Mikrobiom umfasst die Gesamtheit aller Mikroorganismen, die ein Makroorganismus (Mensch, Tiere, Boden oder Biogasanlage) besiedelt. Aufgrund der Komplexit{\"a}t und Individualit{\"a}t der interagierenden Parameter ist das Zusammenwirken des Mikrobioms nicht ausreichend erforscht. Diese Studie fokussiert auf die Beeinflussung des Mikrobioms von Biogasanlagen durch chemische, technische und mikrobielle Faktoren.}, language = {de} } @misc{OviedoOcanaAbendrothDominguezRiveraetal., author = {Oviedo-Oca{\~n}a, Edgar Ricardo and Abendroth, Christian and Dominguez Rivera, Isabel Cristina and S{\´a}nchez Ferrer, Antoni and Dornack, Christina}, title = {Life cycle assessment of biowaste and green waste composting systems: A review of applications and implementation challenges}, series = {Waste Management}, volume = {171}, journal = {Waste Management}, issn = {1879-2456}, doi = {10.1016/j.wasman.2023.09.004}, pages = {350 -- 364}, abstract = {Composting is one of the most widely applied methods for recycling organic waste. This process has been proposed as one option that facilitates the reincorporation of materials into the production cycle. However, composting also generates environmental impacts. Life Cycle Assessment (LCA) is the most common approach to evaluate the environmental impacts of a process at different system stages. Nevertheless, applying LCA in composting facilities is challenging due to the extensive information required, the lack of standardization on the initial assumptions, the definition of system boundaries, and the high diversity of existing composting technologies. This paper systematically reviews LCA studies in biowaste and/or green waste composting. The study highlights the challenges that should be met in order to improving the application of LCA to evaluate the environmental impacts of this type or waste treatment strategy. The review protocol used identified 456 papers published between 2010 and 2022. After the screening, 56 papers were selected, read, and thoroughly analyzed. The results show that: i) about 68\% of the studies aimed to compare composting with other solid waste management options; ii) there was a wide diversity among the impact categories considered, which predominantly included climate change and ozone depletion; iii) there was no consensus on the functional unit or the system boundaries; iv) the main gaseous emissions studied were ammonia, methane, and nitrogen oxide, which were generally determined by emission factors; v) the avoided environmental impacts associated with the end-product quality and its application as an organic amendment or soil improver were ignored. This work demonstrates the complexity of conducting credible and valid composting LCA studies and proposes seven recommendations for improving the application of this assessment methodology to analyze this waste management alternative.}, language = {en} } @misc{MarkowskiAbendrothLapushynskaetal., author = {Markowski, Jens and Abendroth, Christian and Lapushynska, Alina and Lohse, Anja}, title = {Experiences from the commissioning of a bioleaching plant for the recovery of gold from printed circuit boards}, series = {Biomining´23 - 11th International Symposium on Biomining}, journal = {Biomining´23 - 11th International Symposium on Biomining}, publisher = {Mining Engineering}, address = {Falmouth (UK)}, abstract = {Production waste from the manufacture of PCB often contains gold-containing contact-strips, whereby the gold content is < 1 \%. Recycling of these gold coatings with conventional melting processes is technically hardly, since the carrier materials often contain mechanical reinforcements and flame retardants in addition to thermosetting plastics. With mechanical recycling, gold losses of 50\% are possible. Therefore, a bioleaching plant for the recovery of gold and copper as preliminary stage for the smelting process has been in operation on m\&k´s site since May 2022. The bioleaching is realized with iron and sulfur oxidizing bacteria, e.g. Leptospirilum ferrooxidans. The apparatus consists of a 400 litres-leaching bioreactor and peripheral equipment (fermenter, cementation, filters). The plant can process up to 10 kg of gold-containing PCB waste per batch, while simultaneously regenerating a second batch of bioleaching fluid. The process can recover up to 450 mg goldtinsel and 25 g copperpowder per Kilogramm input.}, language = {en} } @misc{OttoWitkabelBarthetal., author = {Otto, Pascal and Witkabel, Philipp and Barth, Maximilian and Ammar, Aziz Ben and Rocktaeschel, Benjamin and Torrent, Daniel and Latorre-Per{\´e}z, Adriel and Krause, Maximilian and Abendroth, Christian}, title = {Adaptation of the anaerobic microbiome for in-situ power-to-CH4 processes through fuzzy logic control of H2 input}, series = {Bioresource technology reports}, volume = {31}, journal = {Bioresource technology reports}, publisher = {Elsevier BV}, address = {Amsterdam}, issn = {2589-014X}, doi = {10.1016/j.biteb.2025.102194}, pages = {1 -- 11}, abstract = {This study presents the first application of fuzzy logic control (FLC) for regulating in-situ biological methanation via H2 injection in a fixed-bed reactor. Given the role of CH4 as a storable and infrastructure-compatible energy carrier, the aim was to improve CH4 production by dynamically adapting the H2 supply to the metabolic capacity of the microbiome. This will pave the way for the biological utilisation and storage of renewable H2. Over a 226- day operational period, H2 input was gradually increased based on real-time headspace gas measurements. Coupling the gradual increase in H2 supply with real-time gas composition data allowed the microbiome to adapt dynamically to changing process conditions. This approach led to a 49 \% increase in CH4 concentration, from 58.4 \% to 87.0 \%, and improved H2 conversion rates from 98.2 \% to 99.0 \%. Chemical analyses of COD, organic acids and nitrogen were performed, as well as taxonomic analyses using 16S rRNA sequencing, and multivariate methods were applied to confirm the adaptation of the microbiome to the FLC H2 injection. The adopted microbial community was dominated by strictly hydrogenotrophic methanogens, Methanoculleus and Methanobacterium, while increased abundances of Petrimonas, Rectinema, Syntrophomonas, and Geobacter indicate interspecies H2 transfer and syntrophic cooperation enhancing methanogenesis. These findings demonstrate that FLC-based H2 control enables dynamic adjustment of in-situ methanation, optimising the interaction between hydrogenogenic, fermentative, syntrophic acetate-oxidising, and hydrogenotrophic microorganisms. This work introduces an adaptive control strategy that supports stable and efficient bio-CH4 production and represents a significant advance in the field of power-to-gas technologies.}, language = {en} } @misc{HozadAbendroth, author = {Hozad, Ahmad Shabir and Abendroth, Christian}, title = {Electro-composting : an emerging technology}, series = {Fermentation}, volume = {11}, journal = {Fermentation}, number = {7}, publisher = {MDPI AG}, address = {Basel}, issn = {2311-5637}, doi = {10.3390/fermentation11070401}, pages = {1 -- 23}, abstract = {This study focuses on electrical stimulation for composting. Using the PSALSAR method, a comprehensive systematic review analysis identified 22 relevant articles. The examined studies fall into four main systems: electric field-assisted aerobic composting (EAAC), electrolytic oxygen aerobic composting (EOAC), microbial fuel cells (MFCs), and thermoelectric generators (TEGs). Apart from the main systems highlighted above, bioelectrochemically assisted anaerobic composting (AnCBE, III) is discussed as an underexplored system with the potential to improve the efficiency of anaerobic degradation. Each system is described in terms of key materials, composter design, operating conditions, temperature evolution, compost maturity, microbial community, and environmental outcomes. EAAC and EOAC systems accelerate organic matter decomposition by improving oxygen distribution and microbial activity, whereas MFC and TEG systems have dual functioning due to the energy generated alongside waste degradation. These innovative systems not only significantly improve composting efficiency by speeding up organic matter breakdown and increasing oxygen supply but also support sustainable waste management by reducing greenhouse gas emissions and generating bioelectricity or heat. Together, these systems overcome the drawbacks of conventional composting systems and promote future environmental sustainability solutions.}, language = {en} } @misc{Puchol‐RoyoPascualOrtega‐Legarretaetal., author = {Puchol-Royo, Roser and Pascual, Javier and Ortega-Legarreta, Asier and Otto, Pascal and Tideman, Jeroen and de Vries, Sjoerd-Jan and Abendroth, Christian and Tanner, Kristie and Porcar, Manuel and Latorre-Perez, Adriel}, title = {Metagenomic insights into the ecology, taxonomy and metabolic capabilities of 'Candidatus Darwinibacteriales' Ord. Nov. (formerly MBA03), a potential key player in anaerobic digestionstion}, series = {Microbial biotechnology}, volume = {18}, journal = {Microbial biotechnology}, number = {12}, publisher = {Wiley}, address = {Hoboken, NJ}, issn = {1751-7915}, doi = {10.1111/1751-7915.70258}, pages = {1 -- 16}, abstract = {Biogas, a mix of CO2, CH4 and small proportions of other gases, is a biofuel obtained by anaerobic digestion (AD). Biogas production is often considered a black box process, as the role and dynamics of some of the microorganisms involved remain undisclosed. Previous metataxonomic studies in the frame of the MICRO4BIOGAS project (www. micro 4biog as. eu) revealed that MBA03, an uncharacterised and uncultured bacterial taxon belonging to phylum Bacillota, was very prevalent and abundant in industrial full-scale AD plants. Despite the efforts, this taxon has not yet been cultivated, which makes the analysis of its taxonomy, ecology and metabolism even more challenging. In the present work, 30 samples derived from anaerobic digesters were sequenced, allowing the reconstruction of 108 metagenome-assembled genomes (MAGs) potentially belonging to MBA03. According to phylogenetic analyses and genomic similarity indices, MBA03 was classified as a new bacterial order, proposed as 'Candidatus Darwinibacteriales' ord. nov., which includes 'Candidatus Darwinibacter acetoxidans' gen. nov., sp. nov. of 'Candidatus Darwinibacteriaceae' fam. nov., along with 'Candidatus Wallacebacter cryptica' gen. nov., sp. nov. of the 'Candidatus Wallacebacteriaceae' fam. nov. Ecotaxonomic studies determined that AD processes are the main ecological niche of 'Candidatus Darwinibacteriales'. Moreover, metabolic predictions identified Darwinibacteraceae members as putative syntrophic acetate-oxidising bacteria (SAOB), as they encode for the reversed Wood-Ljungdahl (W-L) pathway coupled to the glycine cleavage system. This suggests that Darwinibacteraceae members could work in collaboration with hydrogenotrophic methanogenic archaea to produce methane in industrial biogas plants. Overall, our findings present 'Candidatus Darwinibacteriales' as a potential key player in anaerobic digestion and pave the way towards the complete characterisation of this newly described bacterial taxon, which has not yet been cultured.}, language = {en} } @misc{JansenKaufmanHozadetal., author = {Jansen, Nils and Kaufman, Daniel and Hozad, Ahmad Shabir and Alipoursarbani, Mozhdeh and Kochlamazashvili, Rati and Kunchulia, Ilia and Besalatpour, Aliasghar and Abendroth, Christian}, title = {From Waste to Wealth : Georgiens Bio-Fabrik f{\"u}r landwirtschaftliche Reststoffe}, series = {M{\"u}ll und Abfall : Fachzeitschrift f{\"u}r Kreislauf- und Ressourcenwirtschaft}, volume = {58}, journal = {M{\"u}ll und Abfall : Fachzeitschrift f{\"u}r Kreislauf- und Ressourcenwirtschaft}, number = {1}, publisher = {Erich Schmidt Verlag GmbH \& Co. KG}, address = {Berlin}, issn = {1863-9763}, doi = {10.37307/j.1863-9763.2026.01.06}, pages = {19 -- 24}, abstract = {Die Landwirtschaft spielt in Georgien trotz zunehmender Urbanisierung eine zentrale wirtschaftliche Rolle, insbesondere in l{\"a}ndlichen und gebirgigen Regionen, wobei 16 \% der Erwerbst{\"a}tigen rund 6,2 \% des BIP erwirtschaften. Herausforderungen wie geringe Wettbewerbsf{\"a}higkeit, unzureichende Landverteilung, fehlende moderne Technologien, geringe Abfallverwertung und Umweltbelastungen durch unsachgem{\"a}ße Entsorgung von landwirtschaftlichen R{\"u}ckst{\"a}nden erfordern innovative Ans{\"a}tze. Das Waste2Wealth- Projekt (W2W), gef{\"o}rdert vom BMUKN, zielt darauf ab, diese R{\"u}ckst{\"a}nde systematisch zu nutzen und Wissen, Technologie und Praxis miteinander zu verbinden. Hierzu werden Potenzialanalysen f{\"u}r landwirtschaftliche Reststoffe durchgef{\"u}hrt, Verwertungswege wie Biogasproduktion und Biokohleherstellung gepr{\"u}ft, und praxisnahe Instrumente wie das W2W-Whitebook, digitale Lernplattformen („Digitales LERNHAUS"), Train-of-Trainer-Module und ein mobiler Demonstrationscontainer implementiert. Das Projekt f{\"o}rdert Kapazit{\"a}tsaufbau, Stakeholder-Engagement und den Technologietransfer zwischen Deutschland und Georgien, um eine zirkul{\"a}re Bio{\"o}konomie zu etablieren, die {\"o}kologische Nachhaltigkeit, wirtschaftliche Entwicklung und die Nutzung lokaler Ressourcen verbindet. Despite increasing urbanisation, agriculture plays a central economic role in Georgia, especially in rural and mountainous regions, with 16 \% of the working population generating around 6.2 \% of GDP. Challenges such as low competitiveness, inadequate land distribution, a lack of modern technologies, low waste recycling rates and environmental pollution caused by the improper disposal of agricultural residues require innovative approaches. The Waste2Wealth (W2W) project, funded by the BMUKN, aims to systematically utilise these residues and combine knowledge, technology and practice. To this end, potential analyses for agricultural residues are being carried out, recycling methods such as biogas production and biochar production are being examined, and practical tools such as the W2W White Paper, digital learning platforms (‚Digitales LERNHAUS'), train-of-trainer modules and a mobile demonstration container are being implemented. The project promotes capacity building, stakeholder engagement and technology transfer between Germany and Georgia in order to establish a circular bioeconomy that combines ecological sustainability, economic development and the use of local resources.}, language = {de} }