The rewetting of drained peatlands is a promising measure to mitigate carbon dioxide (CO2) emissions by preventing the further mineralization of the peat soil through aeration. While freshwater rewetted peatlands can be significant methane (CH4) sources in the short-term, in coastal ecosystems the input of sulfate-rich seawater could potentially mitigate these emissions. The purpose of the data collection was to examine whether the presence of sulfate, known as an alternative electron acceptor, can cause lower CH4 production and thus, emissions by favoring the growth of sulfate-reducers, which outcompete methanogens for substrate. We therefore investigated underlying variables such as the methane-cycling microbial community along with CH4 fluxes and set them in context with CO2 fluxes along a transect in a coastal peatland before and directly after rewetting. In this way, a conclusion about the short-term greenhouse gas mitigation potential of brackish water rewetting of coastal peatlands could be drawn.
This data collection consists of six data sets, with direct comparisons before and after rewetting of CO2 and CH4 fluxes (Tab. 2) and associated microbial communities (Tab. 1) being the main data. Pore water geochemistry (Tab. 1 and 3) and surface water parameters (Tab. 4) were collected simultaneously to provide potential explanatory variables. The sampling of continuous water level (Tab. 5) within wells and atmospheric weather data (air and soil temperature, relative humidity, photosynthetic photon flux density; Tab. 6) from a weather station was done in addition. Measurements started in June/July/August 2019 after field installation was finalized and were conducted on the drained coastal fen "Polder Drammendorf" on the island of Rügen in North-East Germany. On 26th November 2019, the dike was opened and channeled in order to rewet the peatland with brackish water. Before, the dike separated the peatland from the adjacent bay "Kubitzer Bodden", which is part of a brackish lagoon system connected to the Baltic Sea. Therefore, the peatland was nearly completely flooded and now resembles a shallow lagoon with high fluctuating water levels. We measured along a humidity (pre-rewetting)/water level (post-rewetting) gradient (stations 0-8) towards and across the main North-South oriented drainage ditch, including four stations on the Eastern side of the ditch (1–4), two ditch stations (0, 5) and two stations (6, 7) on the Western side of the ditch. Station 8 was chosen as an additional station farther towards the adjacent bay on the Western side, but was only accessible before rewetting.
CH4 and CO2 fluxes (stations 0-7) were calculated from online gas concentrations measurements using laser-based analyzers and manual closed chambers (Livingston, G. P., & Hutchinson, G. (1995). Enclosure-based measurement of trace gas exchange: Applications and sources of error. In P.A. Matson, & R.C. Harriss (Eds.). Biogenic trace gases: Measuring emissions from soil and water (pp. 14–51). Blackwell Science Ltd., Oxford, UK). Soil cores for microbial, dissolved gas concentrations and isotopic analysis were taken using a Russian type peat corer (De Vleeschouwer, F., Chambers, F. M., & Swindles, G. T. (2010). Coring and sub-sampling of peatlands for palaeoenvironmental research. Mires and Peat, 7, 1–10) before and after rewetting. Each time, we took duplicates at stations 1-8 for this rather labor-intensive process and divided the core into four depth sections: surface, 5–20, 20–40 and 40–50 cm. Subsamples for dissolved gases and stable carbon isotope analyses were taken with tip-cut syringes with a distinct volume of 3 ml (Omnifix, Braun, Bad Arolsen, Germany) and immediately placed into NaCl-saturated vials (20 ml, Agilent Technologies, 5182-0837, Santa Clara, USA) leaving no headspace and closed gas-tight using rubber stoppers and metal crimpers (both: diameter 20 mm, Glasgerätebau Ochs, Bovenden, Germany). Absolute abundances of specific functional target genes, including methane- and sulfate-cycling microorganisms, were measured with quantitative PCR (qPCR) after DNA was extracted (GeneMATRIX Soil DNA Purification Kit, Roboklon, Berlin, Germany) and quantified (Qubit 2.0 Fluorometer, ThermoFisher Scientific, Darmstadt, Germany). Surface and pore water parameters were measured in parallel to the gas measurements and soil coring for microbial analyses. Most surface water variables (pH, specific conductivity, salinity, nutrients, oxygen, sulfate and chloride concentrations, DOC/DIC) were measured in-situ using a multiparameter digital water quality meter or taken to the laboratory as water samples for further analysis. Likewise, pore water/soil variables (pH, specific conductivity, nutrients, metals, sulfate and chloride concentrations, CNS) were either measured in-situ or taken to the laboratory as soil samples. While surface water analysis was only conducted in the drainage ditch before rewetting, it was done along the entire transect after rewetting. In contrast, pore water/soil analysis was mostly conducted before rewetting and only repeated occasionally after rewetting where possible.
As part of PhytOakmeter platform (www.phytoakmeter.de), soil chemical parameters were determined each year between 2014 and 2024. Soil pH was measured using a glass electrode in a 1:2.5 soil-to-0.01 M CaCl2 suspension after one hour of equilibration. Gravimetric soil moisture was assessed with a fully automated moisture analyzer (DBS60-3, KERN & SOHN GmbH, Balingen, Germany), here defined as soil moisture (MOI). Total nitrogen (TN) and total carbon (TC) contents in the soil were analyzed in triplicate through dry combustion using a Vario elemental analyzer (EL III, Elementar, Hanau, Germany), and the carbon-to-nitrogen ratio (TC/TN) was subsequently calculated from these values. To evaluate the potentially bioavailable soil organic carbon and nitrogen for microbial activity, hot water-extractable carbon and nitrogen (HWC and HWN, respectively) were determined following the methods of Ghani et al. (2003) and Schulz et al. (2011). Additionally, the labile organic carbon and nitrogen easily decomposable by soil microorganisms were measured as cold water-extractable carbon (CWC) and nitrogen (CWN) based on procedures described by Zsolnay (1996), Zakharova et al. (2015), and Schmidt et al. (2017). Ammonium and nitrate (NH4±N and NO3—N, respectively) were quantified, with their sum representing the total mineral nitrogen content (Nmin).
Zielsetzung:
Die Verwendung von chemischen antimikrobiellen Stoffen wie Antibiotika, Pestiziden und Kupfer in der Landwirtschaft führt zu erheblichen Umwelt- und Gesundheitsproblemen. Die Rückstände dieser Stoffe verbleiben im Boden und im Wasser und beeinträchtigen die Lebensfähigkeit von Mikroorganismen. Sie stören das natürliche mikrobielle Gleichgewicht in der Umwelt, verringern die biologische Vielfalt und ökologische Funktion, schädigen nützliche Organismen, verunreinigen Trinkwasservorräte und führen zu Bodendegradation und Nährstoffverarmung. Besonders besorgniserregend ist jedoch, dass der nicht-zielgerichtete Einsatz von chemischen antibakteriellen Stoffen zur Resistenzentwicklung von Bakterien und deren Ausbreitung geführt hat. Tatsächlich haben sich die Antibiotikaresistenzen laut WHO zu einer der größten Bedrohung für die öffentliche Gesundheit entwickelt. Resistente Bakterien fordern pro Jahr ca. 1,4 Mio. Opfer (10 Mio. Menschen p.a. im 2050). Besonders der großflächige, ungezielte Einsatz von Antibiotika und Pestiziden in der Landwirtschaft, wird für die Entstehung solcher Resistenzen bei Bakterien verantwortlich gemacht.
Medea Biopharma GmbH ist ein Biotechnologieunternehmen, das eine neue Generation nachhaltiger und umweltfreundlicher antibakterieller Lösungen auf Basis von Bakteriophagen (kurz: Phagen) entwickelt, um die globale Krise der antimikrobiellen Resistenz zu bekämpfen. Phagen sind sichere, hochspezifische und natürliche Mikroorganismen, die gezielt Bakterien abtöten. Sie sind biologisch abbaubar, umweltfreundlich, hinterlassen keine schädlichen Rückstände und können sich an bakterielle Resistenzen anpassen. Das Ziel des Unternehmens ist es, eine umweltfreundliche Alternative zu herkömmlichen chemischen antibakteriellen Mitteln anzubieten.
Fazit:
MEDEA hat im vergangenen Jahr zentrale Meilensteine beim Aufbau des Labors, der Forschung & Entwicklung erreicht. Gleichzeitig wurde eine klare strategische Positionierung im Veterinärbereich vorgenommen. Daraus resultierte die Auswahl zweier priorisierter Arzneimittelprojekte für Haustiere. Die Entwicklung erster Produktkandidaten wurde gestartet, Regulatorische Analysen und Planungen durchgeführt, erste Fördermittel gesichert und strategische Partnerschaften vorbereitet. Auch auf unternehmerischer Ebene konnte MEDEA internationale Sichtbarkeit erlangen - durch Auszeichnungen bei renommierten Start-up- und Branchenwettbewerben, Teilnahme an internationalen Förderprogrammen.
In den kommenden Monaten liegt der Fokus auf den regulatorischen Angelegenheiten, auf dem Aufbau eigener Produktionskapazitäten sowie auf der Weiterentwicklung anvisierter Produkte.