ARPHA Conference Abstracts最新文献

{"title":"In situ sensor-based monitoring strategies for biogeochemical reactions in mine tailings environments","authors":"Eric Nakoh, Allison Enright","doi":"10.3897/aca.6.e108130","DOIUrl":"https://doi.org/10.3897/aca.6.e108130","url":null,"abstract":"Natural resource extraction and ore processing have significant environmental impacts, such as the generation of wastewater, waste rock and tailings. These waste products are often detrimental to ecosystems, and negatively impact surface and groundwater bodies, often necessitating remediation treatments and long-term management of sites by operators, or, where operators have abandoned a contaminated site, by regulators and government agencies. Such cleanup and monitoring efforts regularly continue for decades after a site is closed. Monitoring efforts usually serve two purposes: characterizing the long-term changes at a site once extraction and processing activities have ceased and evaluating the effectiveness of applied remediation treatments. Monitoring activities are usually mandated in the site’s operating license and usually include frequent field sampling of surface water, groundwater, and soil or sediment, as well as ecological studies describing floral and faunal abundances. These samples are then analyzed to quantify the mobility and phase of contaminants (i.e., toxic heavy metals, hydrocarbons), fundamental water quality parameters (i.e., pH, TDS, alkalinity), and the makeup and function of the microbial community (i.e., culturing, microcosms, ‘omics). The need for skilled workers and constant on-site personnel presence means that environmental monitoring is a high- cost activity for site operators and is a significant financial burden for government and regulatory agencies tasked with managing abandoned legacy mine sites. Over the last decade, rapid developments in platforms for deploying remote scientific instrumentation, lower-cost environmental sensors, and data transmission from remote locations have brought about a renewal of interest in sensor-based environmental monitoring strategies. These approaches offer several advantages, such as lower cost, near real-time data access, and lower exposure risk to toxic and hazardous materials. Here, we will present data collected from a suite of electrochemical sensors deployed in situ at a closed, managed mine site to monitor the effectiveness of remediation treatments in real-time. These results provide proof-of-concept for the effectiveness of sensor-based monitoring technology as part of safe, effective long-term remediation and management strategies.","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135858037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrogen-Driven Microbial Redox Reactions in Deep Geosystems","authors":"Martin Krüger, Anja Dohrmann","doi":"10.3897/aca.6.e107916","DOIUrl":"https://doi.org/10.3897/aca.6.e107916","url":null,"abstract":"In the subsurface, biotic and abiotic processes can generate and consume hydrogen. Hydrogen has a low reduction potential and is thus a highly energetic electron donor when involved in sulfate, carbon dioxide or ferric iron reduction. Although known as important drivers for the deep biosphere, the contributions of different processes to hydrogen turnover in different geosystems still are not well understood. In context with the ongoing transformation to renewable energy resources, underground H2 storage (UHS) in deep porous or salt cavern systems came into focus. In situ microbial and geochemical reactions that consume H2 are highly relevant topics in deep biosphere research, and also are still a major uncertainty during UHS. Consequently, we studied the potential microbial hydrogen oxidation rates – combined with the possible production of metabolic products like H2S, acetic acid or CH4 - in formation fluids from natural gas fields and salt caverns, thereby considering the importance of in situ pressure and temperature conditions, fluid chemistry and mineral composition. In addition, more defined experiments were conducted with selected pure cultures representing important metabolic groups of deep biosphere microorganisms. Several original formation fluids showed immediate H2 consumption. Microorganisms oxidized hydrogen at relevant in situ pressure conditions (up to 100 bar) and tolerated dynamically changing pressure and temperature conditions. The microbial hydrogen oxidation rate was strongly dependent on H2 partial pressures and the availability of e.g., sulfate as a terminal electron acceptor. High-throughput sequencing of 16S rRNA gene amplicons indicated hydrogen oxidation by sulfate reducing bacteria to be the presumed process in the studied porous rock reservoir fluids. In addition, hydrogen turnover by methanogenic and acetogenic as well as iron-reducing microorganisms was investigated. Also, the importance of biotic reactions in relation to abiotic hydrogen turnover processes at mineral surfaces will be discussed.","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135858063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response of Microbial Community Stability to Chemical Oxidation Remediation Process in a Petroleum Hydrocarbon Contaminated Groundwater Site","authors":"Wenjuan Jia, Shengmei Lv, Lirong Cheng, Yi Zhu, Aizhong Ding","doi":"10.3897/aca.6.e108148","DOIUrl":"https://doi.org/10.3897/aca.6.e108148","url":null,"abstract":"The stability of the microbial community is a vital indicator of microbial ecosystems. However, the mechanism of microbial community stability during in situ chemical oxidation in petroleum-hydrocarbon-polluted groundwater is unclear. This study analyzed the biomass, diversity, co-occurrence network feature and negative cohesion of microbial community at different stages to identify the changes in microbial community stability under chemical oxidation. In addition, microbial module compositions and crucial functions were analyzed to further explore the reason for the change in community stability at the module level. Multiple regression analysis was conducted to explore the microbial module explanatory degree to microbial community stability changes. The results indicated that the microbial community stability was destroyed by chemical oxidation. The carbon source effect was the main reason in the early oxidation stage, while the oxidation stress effect was the main reason in the late oxidation stage. Most microbial modules were transformed from K-strategists to r-strategists, and modular keystones were transformed to stress-tolerant species in the oxidation stage. This study suggested that microbial clusters were essential indicators of the microbial community in petroleum hydrocarbon groundwater during the chemical oxidation period.","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135858097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbial Impacts on Colloid-Radionuclide Interactions","authors":"Chloe Morgan, Natalie Byrd, Callum Robinson, Laura Lopez-Odriozola, Sean Woodall, Samuel Shaw, Louise Natrajan, Katherine Morris, Jonathan Lloyd","doi":"10.3897/aca.6.e106921","DOIUrl":"https://doi.org/10.3897/aca.6.e106921","url":null,"abstract":"Microorganisms can play an important role on the behaviour of colloids in natural and engineered environments, which in turn can control the mobility of associated metals and radionuclides. This is especially true in the nuclear fuel cycle, where radionuclides (including uranium) can interact with a broad range of inorganic colloids. This is relevant to the legacy spent nuclear fuel ponds at Sellafield, which house a diverse inventory of waste from the early Magnox reactors. These reactors used uranium metal as a fuel encased in a magnesium non-oxide cladding. Corrosion of the cladding results in the release of radionuclides, primarily uranium, and the formation of brucite (Mg(OH) 2 ) phases which are present both in the corroded Magnox sludge at the base of the pond and suspended in the water column as colloids (Gregson et al. 2011). These brucite colloids have the potential to mobilise insoluble phases providing an important pathway for radionuclide migration. The spent nuclear fuel ponds are maintained at high pH to minimise corrosion of the cladding, however significant corrosion has still occurred. Despite the seemingly inhospitable conditions in spent nuclear fuel ponds, numerous studies have found microorganisms capable of surviving in spent nuclear fuel ponds (Dekker et al. 2014, Foster et al. 2020, Ruiz-Lopez et al. 2020). Previous work has demonstrated increased abiotic sorption of strontium to brucite in the presence of organic matter derived from Pseudanabaena catenata (Ashworth et al. 2018), which dominates algal blooms in the ponds. In this study we focus on uranium interactions with colloidal brucite in the presence of microbes adapted to high pH environments under conditions relevant to the spent nuclear fuel ponds at Sellafield.","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135854780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Different manure management methods impact on nitrogen use efficiency - comparison of four dairy farms in Hokkaido Japan","authors":"Haruka Sato, Yoshitaka Uchida","doi":"10.3897/aca.6.e107926","DOIUrl":"https://doi.org/10.3897/aca.6.e107926","url":null,"abstract":"To maintain balanced biogeochemical cycles, minimizing the nutrient wastes from agricultural activities is critically important. Agricultural activities such as dairy farming produce large amounts of nitrogen waste in natural ecosystems. The increased nitrogen waste from dairy farming potentially causes environmental damage, such as eutrophication and greenhouse gas emissions. To accurately assess these changes in nitrogen wastes from dairy farming systems, measurements of variable parameters related to the nitrogen cycle (e.g., nitrogen gas emissions, nitrogen loss to water ecosystems), but these are time-consuming. Instead, calculating farm gate-level nitrogen surplus and nitrogen use efficiency (NUE) is a practical method to estimate the nitrogen waste from dairy farming systems. The nitrogen surplus and NUE are calculated based on the difference and ratio between nitrogen input (such as fertilizer and feed) and nitrogen output (such as milk and meat) on each farm. The data needed to calculate the nitrogen input and output can be obtained by interviewing farmers. Thus it is often easier than directly measuring nitrogen cycle parameters. In addition, it is known that excess nitrogen wastes are often related to improper manure management (i.e., manure is not efficiently collected and returned to the farm as nutrients) on dairy farms. In the dairy farming regions in Japan, particularly in Hokkaido, improper manure management can occur because of the short grass growing season and long winter, which means a large amount of manure has to be stored for an extended period. However, few previous studies quantitatively linked manure management and NUE in Japan. Thus, a study was needed to assess the link between manure management styles and the farm gate-level nitrogen surplus and NUE. Using the data from several Japanese dairy farms, we clarified the following: Whether nitrogen losses during manure management can be a controlling factor for the NUE of the whole farm or not. Other management options necessary to keep the NUE within an appropriate range. Whether nitrogen losses during manure management can be a controlling factor for the NUE of the whole farm or not. Other management options necessary to keep the NUE within an appropriate range. Interviews were conducted with four small-scale (34–42 milked cows per farm) grazing dairy farmers in Central and Eastern Hokkaido to estimate their nitrogen balance and calculate NUE. The data for the year 2022 was used to calculate the NUE and nitrogen surplus. The data included all the fertilizer and feed information as nitrogen inputs, while milk and meat production as nitrogen outputs. Also, the basic information about the farm (e.g., area and stocking rates) was collected. Then, the total nitrogen and inorganic nitrogen (ammonium-form nitrogen and nitrate-form nitrogen) in excreta samples at various stages from a barn to pre-application in each farm were measured to assess the amount of nitrogen loss and n","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135858947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal variation of gross ecosystem productivity of periphyton in three post-mining lakes in the Czech Republic, Europe","authors":"Kateřina Čapková, Klára Řeháková, Tomáš Bešta, Petr Čapek, Jan Mareš, Eliška Konopáčová","doi":"10.3897/aca.6.e108115","DOIUrl":"https://doi.org/10.3897/aca.6.e108115","url":null,"abstract":"We investigated the seasonal variation of gross ecosystem productivity (GEP) of periphyton biomass in three post-mining lakes in the Czech Republic. These lakes were established as part of recultivation efforts after coal mining activities and resulted in a unique series of anthropogenic oligotrophic lakes of gradual successional age. Periphyton is ubiquitous in aquatic habitats and performs numerous environmental functions such as nutrient cycling and self-purifying of aquatic ecosystems. Well-developed periphyton mat can be formed within a few weeks, so it can quickly become the dominant of littoral zone of newly established lakes. In studied post-mining lakes, the highly developed periphytic community covers the littoral zone of each lake to the depth of 2m (Bešta et al. 2022, Konopáčová et al. 2023) Fig. 1. We aimed to shed some new light on the processes controlling the dynamics of primary productivity in oligotrophic lakes. The accurate estimation of primary productivity is crucial for understanding the functioning of aquatic ecosystems, as primary productivity serves as the primary source of autochthonous carbon in these systems. In addition to phytoplankton, periphyton can significantly contribute to primary productivity in littoral zones, known for their high productivity and biodiversity. Conducting in situ measurements provides the most accurate means of inferring the metabolic activity of primary producers in littoral zones. We conducted detailed seasonal in-situ periphyton gross primary production (GPP) measurements in three post-mining lakes with different successional ages (Čapková et al. 2022). GPP and NPP of periphytic biomass were determined using direct in-situ measurement of O 2 fluxes. O 2 production and consumption were measured over 5 hours of in-situ light and dark gas-tight glass bottle incubation. Bottles were filled with the lake water from the corresponding depth, and a similar amount of periphytic biomass was enclosed Fig. 2. We used the Fibox3 fibre-optic oxygen meter coupled with a PSt3 oxygen sensor (PreSens, Regensburg, DE) to measure changes in O 2 concentration. The O 2 fluxes were normalized to periphytic biomass in each bottle (measured as total organic carbon). Data were corrected for O 2 concentration changes in dark and light gas-tight bottles containing lake water without periphytic communities. This setup enabled us to monitor online oxygen flux, therefore, insights into metabolic activities. The primary productivity was measured in real-time, allowing us to capture the quantitative effect of various environmental drivers on periphyton productivity, i.e. phosphorus concentration and light intensity, as they are known to play significant roles in primary productivity. We showed that the primary production of periphyton mats exhibited seasonal variations, with higher productivity observed in spring compared to other seasons. This observation could be attributed to the occurrence of winter/spring upwelling e","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135858488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Co-transport of Microplastics and a surrogate for Human Enteric Viruses in a saturated column packed with Quartz Sand","authors":"Ahmad Ameen, Birgit Bromberger, Patrick Mester, Alexander Kirschner, Alfred Blaschke, Margaret Stevenson","doi":"10.3897/aca.6.e108005","DOIUrl":"https://doi.org/10.3897/aca.6.e108005","url":null,"abstract":"Groundwater can be contaminated with infective human enteric viruses from various sources, such as wastewater treatment plant discharge, landfills, septic tanks, agricultural practices, and artificial groundwater recharge. Anthropogenic pollutants, such as microplastics, may exhibit an affinity to transport biocolloids (bacteria, viruses) further and reduce their degradation rates in the natural environment. Human enteric viruses (poliovirus, hepatitis A, rotavirus, and adenovirus) can adsorb to the abiotic surface of microplastics and are simultaneously present in wastewater discharge. These newly formed clumps of pathogens and microplastics could penetrate deeper into soils as vectors for preferential flow and threaten groundwater systems, triggering a higher risk for drinking water and possibly followed by a disease outbreak. The mechanisms behind the adsorption of human enteric viruses on microplastic surfaces and their potential role in prolonging virus survival and promoting environmental transport remain unclear. This study aims to explore the possibility of co-transport of microplastics and human enteric viruses in saturated porous media, using PRD1 bacteriophage as a surrogate. PRD1 bacteriophages have been widely used as surrogates of rotavirus because they share many fundamental properties and features. Column experiments were performed using quartz sand (soil grain size: 0.60 - 1.30 mm) as a porous media in a 30 cm long and 7 cm diameter column. The column experiments were conducted by maintaining Darcy velocity of 2.65 m/day. Three different influent solution scenarios were considered in the experiments: PRD1 mixed with microplastics, PRD1 alone, and microplastics alone. The enumeration of PRD1 in the effluent solution was performed using quantitative polymerase chain reaction (qPCR) as well as the culture method, in order to differentiate between infective and inactive virus transport. Microplastics were quantified using Solid-Phase Cytometry (SPC). Results were analyzed by calculating the collision and sticking efficiencies of the microplastics and PRD1 using the classical colloid filtration theory and Hydrus 1D modeling tool. There was no evidence of interference or inhibition of microplastics on the performance of qPCR and DNA extraction in the methodological setup. Additionally, the efficacy of qPCR and DNA extraction methods did not yield significantly different results across any of the influent solution conditions. Preliminary results suggest that the presence of microplastics enhanced the transport of PRD1, which led to reduced attachment of PRD1 in the porous media. The concentration of infective phages showed a delayed sharp increase, indicating that there may be a sorption mechanism that delays their breakthrough. It is possible that a portion of the active phages possess a higher sticking efficiency and that population heterogeneity contributes to this phenomenon. A comprehensive understanding of the processes that gover","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135859111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbial activities along a 20 million-year-old pristine oil reservoir","authors":"Lisa Voskuhl, Hannah Möhlen, Christian Schlautmann, Sadjad Mohammadian, Ann-Christin Severmann, Johannes Koch, John Köhne, Erling Rykkelid, Joachim Rinna, Rainer Meckenstock","doi":"10.3897/aca.6.e108098","DOIUrl":"https://doi.org/10.3897/aca.6.e108098","url":null,"abstract":"Studies on oil reservoir microbiology typically take samples from producing reservoirs and sample fluids that have been pumped to the surface. This comes with problems since producing oil reservoirs are affected by production processes leading to changes in environmental conditions and the natural microbiome. Hence, pumped samples do not display an unaltered picture of the spatial distribution and composition of the microorganisms in the reservoir. We took 13 samples from a freshly drilled sediment core of a pristine, heavily biodegraded oil reservoir in the North Sea. Core samples originated from above, within, and below the reservoir. 16S rRNA gene amplicon sequencing of the microbiome revealed distinct differences between sediments and formation water, indicating that studies on microbiomes from formation water alone are not necessarily representative for the microbial processes in an oil reservoir. Fluorescence microscopy showed that microorganisms live in small microcolonies on the sediment surface. CT-scanning with image analysis visualized the water phase distribution inside the reservoir sediments and clearly indicated water-filled voids that might be habitable for microorganisms, enlarging the surface for potential biodegradation. Employing microcosm experiments and reverse isotope labelling, we were able to determine the first degradation rates measured from cores above, within, and below a reservoir ranging from no activity up to 1 mM CO 2 /(g sediment x year) , Results indicate significant degradation potential from autochthonous microorganisms in the reservoir above the water-contact-zone. Evading the general issues of produced oil samples for studying microbiomes results in a more realistic picture of an oil reservoir unaffected by production artefacts.","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135858199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparing the microbial communities in and End-pit lake, active tailings ponds and freshwater bodies from the Athabasca oil sands region","authors":"Montserrat Villegas Torres, Peter Dunfield","doi":"10.3897/aca.6.e108146","DOIUrl":"https://doi.org/10.3897/aca.6.e108146","url":null,"abstract":"The Athabasca oil sands region in northern Alberta is home to one of the largest bitumen deposits in the world. Oil sands are mostly recovered via surface mining and the oil extraction is achieved with hot caustic water and diluents, a process that produces liquid tailings waste (CEC 2020, Schramm et al. 2000). It is estimated that 1 m 3 of bitumen produces around 4 m 3 of tailings, which are contained in large tailings ponds (Mikula et al. 1996). End-pit lakes are a potential strategy to reclaim mining pits created by oil sands mining. They may be formed by filling a mined-out pit with tailings and then capping it with a layer of fresh water. With time, tailings undergo a dewatering process in which they become denser and release water to the cap water (Charette et al. 2012). Base Mine Lake (BML) is the first full-scale demonstration end-pit lake in the Canadian oil sands industry. This former tailings pond was initially capped in 2012 with a 5 m layer of freshwater to allow for consolidation of the tailings and the stimulation of aerobic microbial communities to biodegrade the organic pollutants. Since its establishment, BML has been extensively monitored to assess the improvement in water quality. The present research focused on determining how the eukaryotic and bacterial communities in BML compare to those in local freshwater bodies and active tailings ponds. Eleven reference sites, including freshwater reservoirs, natural lakes, and 9- to 14-year-old excavated pits filled with water, also known as borrow pits, were sampled along with 5 active tailings ponds and BML during the summer of 2022. Microbial communities were assessed via next-generation sequencing of PCR amplicons of the 16S rRNA gene for bacteria and the 18S rRNA gene for eukaryotes. Alpha-diversity analysis of the eukaryotic communities showed that BML has greater species richness and evenness than active tailings ponds, but lower than freshwater systems. The bacterial community in both BML and active tailings ponds is dominated by Proteobacteria , but the relative abundance of Actinobacteriota is similar between BML and freshwater. Beta-diversity analysis revealed that eukaryotic and bacterial communities in BML cluster distinctly from both the freshwater controls and active tailings ponds, however, the composition of the eukaryotic community shows some overlap with certain freshwater systems (Fig. 1). The results of this research suggest that, 10 years after its formation, the microbial communities in BML are intermediate between an active tailings pond and a freshwater lake.","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135858231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ancient organic matter in black shales as a carbon source for deep subsurface life","authors":"Lotta Purkamo, Riikka Kietäväinen, Lukas Kohl, Maija Nuppunen-Puputti, Ellen Lalk, Shuhei Ono, Malin Bomberg","doi":"10.3897/aca.6.e108123","DOIUrl":"https://doi.org/10.3897/aca.6.e108123","url":null,"abstract":"The fluids at black schist-rich bedrock in the Fennoscandian shield have been shown to carry extensive methane (Kietäväinen and Purkamo 2015, Kietäväinen et al. 2017). The sources of methane, abiotic, microbial, thermogenic, or their mixtures, are not well understood (Etiope and Sherwood Lollar 2013, Douglas et al. 2017). While previous field and laboratory studies have concentrated on oxic degradation of relatively low metamorphic grade black shales (e.g., Matlakowska et al. 2012, Petsch et al. 2005), our goal was to explore the genetic potential of microbial communities in naturally anoxic, oligotrophic and moderately saline bedrock fluids in contact with high-metamorphic grade organic carbon containing black schist. We tested if the microbial metabolisms could explain the extensive methane detected from the fluids at black schist -rich bedrock in the Fennoscandian shield. We aimed to determine the difference between abiotic and biotic methane formation in Palaeoproteorozoic bedrock using novel methane isotopologue measurements and evaluate the ability of natural microbial communities to use black schists as a carbon source in enrichment cultures and compare these to the previously reported cultures. Two study sites, namely the Outokumpu Deep Scientific Drill Hole at depth of 1470 m and Juuka/Miihkali116 overflowing deep drill hole in Finland, were selected for comprehensive geochemical and microbiological sampling. The sampling campaign involved collecting samples for methane isotopologues, intrinsic microbial community, and fluid for inoculation of laboratory microcosms. Ground and sterilized black shists of two different maturities obtained from Finnish bedrock, 13 C-labeled graphite, cellulose, acetate and CO 2 were used as different carbon sources for intrinsic deep subsurface fluids, and these microcosms were incubated for 8-20 months. Subsequently, the gas phase of the microcosms was analyzed for CH 4 , CO 2 , N 2 O, O 2 , and N 2 concentrations, as well as isotopic ratios of carbon in CH 4 and CO 2 . Bacterial, archaeal and fungal communities were characterized using phylogenetic marker gene amplicon sequencing from both the intrinsic deep subsurface fluids and the microcosms after the incubation period. The results of this study indicate that methane in these sites is likely formed abiotically, as evidenced by the isotopologue data and the absence of methanogenic archaea in the microbial communities. Moreover, the gas data and isotope ratios obtained from the microcosms suggest that graphitic carbon is predominantly transformed into carbon dioxide rather than methane, further supporting the isotopologue data. Throughout the incubation period, the microbial communities within the microcosms exhibited dynamic changes. Specific microbial groups known for their capacity to utilize complex or recalcitrant organic matter and xenobiotics were observed, indicative of the challenging, oligotrophic and nutrient-deficient subsurface environments.","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135858360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}