{"type": "FeatureCollection", "features": [{"id": "10.1021/acs.est.1c03586", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-25T16:17:29Z", "type": "Journal Article", "created": "2021-11-02", "title": "Impact of Periodic Polarization on Groundwater Denitrification in Bioelectrochemical Systems.", "description": "Nitrate contamination is a common problem in groundwater around the world. Nitrate can be cathodically reduced in bioelectrochemical systems using autotrophic denitrifiers with low energy investment and without chemical addition. Successful denitrification was demonstrated in previous studies in both microbial fuel cells and microbial electrolysis cells (MECs) with continuous current flow, whereas the impact of intermittent current supply (e.g., in a fluidized-bed system) on denitrification and particularly the electron-storing capacity of the denitrifying electroactive biofilms (EABs) on the cathodes have not been studied in depth. In this study, two continuously fed MECs were operated in parallel under continuous and periodic polarization modes over 280 days, respectively. Under continuous polarization, the maximum denitrification rate reached 233 g NO3--N/m3/d with 98% nitrate removal (0.6 mg NO3--N/L in the effluent) with negligible intermediate production, while under a 30 s open-circuit/30 s polarization mode, 86% of nitrate was removed at a maximum rate of 205 g NO3--N/m3/d (4.5 mg NO3--N/L in the effluent) with higher N2O production (6.6-9.3 mg N/L in the effluent). Conversely, periodic polarization could be an interesting approach in other bioelectrochemical processes if the generation of chemical intermediates (partially reduced or oxidized) should be favored. Similar microbial communities dominated byGallionellaceaewere found in both MECs; however, swapping the polarization modes and the electrochemical analyses suggested that the periodically polarized EABs probably developed a higher ability for electron storage and transfer, which supported the direct electron transfer pathway in discontinuous operation or fluidized biocathodes.", "keywords": ["bioelectrochemical systems (BESs)", "periodic polarization", "Autotrophic Processes", "Technology and Engineering", "denitrification", "Nitrates", "AUTOTROPHIC DENITRIFICATION", "EABs", "Bioelectric Energy Sources", "NITRATE-CONTAMINATED GROUNDWATER", "02 engineering and technology", "6. Clean water", "REDUCTION", "REMOVAL", "13. Climate action", "Earth and Environmental Sciences", "BACTERIA", "ACETATE", "Denitrification", "MICROBIAL FUEL-CELLS", "ELECTRON-TRANSFER", "BIOFILM", "0210 nano-technology", "Groundwater", "STORAGE"]}, "links": [{"href": "https://pubs.acs.org/doi/pdf/10.1021/acs.est.1c03586"}, {"href": "https://doi.org/10.1021/acs.est.1c03586"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Environmental%20Science%20%26amp%3B%20Technology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1021/acs.est.1c03586", "name": "item", "description": "10.1021/acs.est.1c03586", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1021/acs.est.1c03586"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2021-11-02T00:00:00Z"}}, {"id": "10.1039/c7ra12316g", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-25T16:17:56Z", "type": "Journal Article", "created": "2018-01-15", "title": "Composition and role of the attached and planktonic microbial communities in mesophilic and thermophilic xylose-fed microbial fuel cells", "description": "

A mesophilic (37 \u00b0C) and a thermophilic (55 \u00b0C) two-chamber microbial fuel cell (MFC) were studied and compared for their power production from xylose and the anode-attached, membrane-attached and planktonic microbial communities involved.

", "keywords": ["570", "waste-water", "116 Chemical sciences", "116", "bacterium", "01 natural sciences", "7. Clean energy", "biofilm", "3. Good health", "Chemistry", "sludge", "13. Climate action", "extracellular electron-transfer", "geobacter-sulfurreducens", "electricity-generation", "phylogenetic analyses", "enrichment culture", "performance", "0105 earth and related environmental sciences"]}, "links": [{"href": "http://pubs.rsc.org/en/content/articlepdf/2018/RA/C7RA12316G"}, {"href": "https://doi.org/10.1039/c7ra12316g"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/RSC%20Advances", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1039/c7ra12316g", "name": "item", "description": "10.1039/c7ra12316g", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1039/c7ra12316g"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2018-01-01T00:00:00Z"}}, {"id": "10.1128/msystems.00562-19", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-25T16:19:12Z", "type": "Journal Article", "created": "2020-01-13", "title": "Transcriptomic Response of Nitrosomonas europaea Transitioned from Ammonia- to Oxygen-Limited Steady-State Growth", "description": "

Nitrification is a ubiquitous microbially mediated process in the environment and an essential process in engineered systems such as wastewater and drinking water treatment plants. However, nitrification also contributes to fertilizer loss from agricultural environments, increasing the eutrophication of downstream aquatic ecosystems, and produces the greenhouse gas nitrous oxide. As ammonia-oxidizing bacteria are the most dominant ammonia-oxidizing microbes in fertilized agricultural soils, understanding their responses to a variety of environmental conditions is essential for curbing the negative environmental effects of nitrification. Notably, oxygen limitation has been reported to significantly increase nitric oxide and nitrous oxide production during nitrification. Here, we investigate the physiology of the best-characterized ammonia-oxidizing bacterium, Nitrosomonas europaea , growing under oxygen-limited conditions. Nitrification is a ubiquitous microbially mediated process in the environment and an essential process in engineered systems such as wastewater and drinking water treatment plants. However, nitrification also contributes to fertilizer loss from agricultural environments, increasing the eutrophication of downstream aquatic ecosystems, and produces the greenhouse gas nitrous oxide. As ammonia-oxidizing bacteria are the most dominant ammonia-oxidizing microbes in fertilized agricultural soils, understanding their responses to a variety of environmental conditions is essential for curbing the negative environmental effects of nitrification. Notably, oxygen limitation has been reported to significantly increase nitric oxide and nitrous oxide production during nitrification. Here, we investigate the physiology of the best-characterized ammonia-oxidizing bacterium, Nitrosomonas europaea , growing under oxygen-limited conditions.