ARPHA Conference Abstracts最新文献

{"title":"Microbial community ecosystem network model for chemical energy transport","authors":"Mayumi Seto, Michio Kondoh","doi":"10.3897/aca.6.e108960","DOIUrl":"https://doi.org/10.3897/aca.6.e108960","url":null,"abstract":"Microorganisms thriving in low-energy ecosystems have evolved diverse strategies to sustain life, including individual-level energy conservation, optimizing energy utilization through interspecies competition, and mutually beneficial interspecies syntrophy. This study introduces a novel community-level strategy to enhance energy efficiency. We employed an oxidation-reduction (redox) reaction network model to capture the intricate metabolic interactions within microbial communities. Our findings highlight the importance of microbial functional diversity in facilitating metabolic handoffs, leading to an improved energy utilization efficiency. Moreover, the mutualistic division of labor and the resulting complexity of redox pathways actively facilitate material cycling, thereby enhancing energy exploitation. These findings provide new insights into the potential of self-organized ecological interactions to develop efficient energy utilization strategies, with significant implications for the functioning and evolution of microbial ecosystems.","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136033588","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 Community Dynamics in Base Mine Lake, the First End-Pit Lake in the Alberta Oil sands Industry","authors":"Angela Smirnova, Peter Dunfield, Chantel Furgason, Andriy Sheremet, Felix Nwosu, Joel Dacks","doi":"10.3897/aca.6.e108268","DOIUrl":"https://doi.org/10.3897/aca.6.e108268","url":null,"abstract":"Oil extraction from bitumen in the Athabasca region of northeastern Alberta, comprises a large segment of the Canadian economy. However, the process of oil extraction from surface mined oil sands ores results in diverse environmental issues including disturbance of land areas and habitats for wildlife, as well as production of large volumes of fluid tailings containing many compounds of concern for the environment. Land reclamation strategies of most oilsands operations propose the construction of end-pit lakes (EPL) to contain and biodegrade tailings, eventually becoming integrated into local watersheds. We used 16S/18S rRNA gene amplicon and metagenome sequencing to monitor prokaryotic and eukaryotic communities in the first full-scale pilot EPL of the Canadian oilsands, Base Mine Lake (BML) Fig. 1, over 6 years from 2015-2021, and compared them with communities from two active tailings ponds, Mildred Lake Setting Basin (MLSB) and Southwest in-Pit (SWIP), as well as with communities from a more natural freshwater body, Beaver Creek Reservoir (BCR). Alpha diversity in BML is intermediate to diversities in active tailings ponds and a natural lake, although highly variable with time, depth, and season. Microbial communities in BML resemble neither freshwater lake nor active tailings communities, although a structural shift of either microbial community occurred every year, and 2021 was a year of the most profound effect. Moreover, metabolic functions in BML also shifted every year, with the most dramatic shift for photosynthesis-related genes. Temporal changes among protists identified in BML were characterized by enrichment of species designated as picophytoplankton: Cryptomonas , Mychonastes , Trebouxiophyceae , and Dinobryon , and among bacterial genera by enrichment of common freshwater lake species or bacterioplankton: Ca . Fonsibacter, Sporichthyaceae , Ca. Planktophila, Microbacteriaceae ML602J-51, Ilumatobacteraceae CL500-29 group. Network analysis identified a potential microbial consortium between newly enriched species of picophytoplankton and bacterioplankton. Heterotrophic bacteria with streamlined genomes may overcome auxotrophic limitations by scavenging metabolites and other compounds produced by phototrophs presumably via chemotaxis behaviour. We propose that the formation of the consortium might serve as a biomarker for reclamation process of an oil sands tailings pond.","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136032525","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":"Dispersal and Distribution of Thermophilic Endospores in Deep-Sea Ecosystems","authors":"Francesco Bisiach, Daniel Yakimenka, Casey Hubert","doi":"10.3897/aca.6.e108260","DOIUrl":"https://doi.org/10.3897/aca.6.e108260","url":null,"abstract":"The distance-decay relationship is a central concept in biogeography and spatial biodiversity, describing how two distinct entities decrease in similarity as the distance between them increases. The decay of community similarity with geographical distance is driven by multiple factors, such as gene drift, environmental selection, and the accumulation of mutations over time. While the distance-decay relationship has been recognized for several decades, there are certain circumstances where the biogeographical patterns of certain species and communities cannot be predicted by this relationship. The example addressed in this project is the case of thermophilic endospore-forming bacteria found in permanently cold deep ocean sediments. Thermophilic endospores (thermospores) are routinely found on the deep ocean floor, a permanently cold environment that does not support their metabolic activity (Hubert et al. 2009). Thermospores are metabolically dormant states developed by some thermophilic bacteria having optimal growth temperatures between 40°C and 70°C. There is evidence that these heat-loving bacteria originate from the deep subsurface and are transported upward to the deep ocean via geological features of the oceanic crust including geofluid fluxes in high-temperature axial systems and natural hydrocarbon seeps (Gittins et al. 2022). Due to the ability of endospores to stay viable for thousands of years and resist a wide range of physicochemical stressors, they can disperse over long distances while remaining unaffected by changing factors such as selection, drift, or mutation (Gittins et al. 2022; Fig. 1). Consequently, these thermospores have the potential to challenge the distance-decay relationship and exhibit unique biogeographical patterns. This work quantifies endospores in sediment cores at and around hydrocarbon seeps using cores from deep-sea Scotian Slope sediments. Given the challenge of quantifying specific groups of endospores (e.g., thermophiles but not mesophiles), high-temperature germination assays that allow tracking of an exponential increase in signal as spores in marine sediment samples germinate and grow can be used. Distinct exponential increases can be attributed to different populations of germinated thermospores in the post-germination growth phase and are being monitored through measurements of sulfate reduction rates (using radiolabelled 35 SO 4 ), strain-specific quantitative PCR (qPCR), and fluorescence in-situ hybridization (FISH) (Rezende et al. 2017). These measurements revealed growth dynamics enabling an estimation of the initial cell numbers using exponential functions. These approaches are being applied to samples obtained via push coring using a remotely operated vehicle at different distances from deep sea hydrocarbon seeps, to test for the presence of abundance gradients of different thermospores. Current results already show a difference in thermospore abundance between sites at different distances from ","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136032804","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":"Studying the isotopic composition of microbial methane with a genetically-tractable methanogen","authors":"Jonathan Gropp, Markus Bill, Daniel Stolper, Dipti Nayak","doi":"10.3897/aca.6.e108567","DOIUrl":"https://doi.org/10.3897/aca.6.e108567","url":null,"abstract":"Nearly all biogenic methane is produced by a group of microorganisms called methanogenic archaea (or methanogens). Methanogens can use a variety of substrates, such as H 2 + CO 2 , acetate, and methylated compounds, for methanogenesis. Previous studies have shown that the stable carbon and hydrogen isotopic compositions of methane produced by methanogens can vary drastically depending on the substrate composition and concentration in the environment. For instance, the concentration of H 2 in the environment has a substantial impact on the isotopic composition of methane derived from hydrogenotrophic methanogenesis (reduction of CO 2 to methane using H 2 as the electron donor) (Valentine et al. 2004, Penning et al. 2005). While there is substantial empirical data on isotopic signatures of methane from different substrates and under different conditions, the physiological and molecular features that control these values are not as well understood. To address this, we are using the metabolically diverse and genetically tractable methanogen, Methanosarcina acetivorans as a model system to uncover key cellular processes that control the stable bulk isotopic composition of methane (i.e., 13 C/ 12 C and D/H ratios), and the distributions of the “clumped” 13 CH 3 D and 12 CH 2 D 2 isotopologues. The methanogen M. acetivorans grows on a wide variety of compounds such as acetate, methanol, methylamines, and methylsulfides. We found that the methylotrophic pathways (for methanol and trimethylamine) and the aceticlastic pathway have large and similar primary hydrogen isotopic effects (α of ~0.45). These data are in contrast to previous findings and imply a minor isotopic exchange between CH 4 and H 2 O (Valentine et al. 2004, Gruen et al. 2018). Focusing first on the methylotrophic pathway, we generated mutants of two key enzymes in the methylotrophic pathway: a) methyl coenzyme M reductase (Mcr) that catalyzes the last step in methanogenesis and b) methyltransferases that catalyze the first step in methylotrophic methanogenesis from methanol (Mta). A mutant with reduced Mcr expression had no observable change in the hydrogen isotopic effect relative to the wild-type, validating the initial observation of minimal H 2 O-CH 4 hydrogen isotopic exchange. One of the Mta mutants, which only expressed a specific methyltransferase isoform, had a smaller carbon isotopic effect relative to the other isoforms (α of ~1.074 vs. ~1.080). Since the isoforms are thought to be identical in structure, the different isotopic effects could result from differential expression of each isoform, or from different kinetic properties. By combining our genetic approaches with traditional and high-resolution isotopic analytical methods, we aim to develop a quantitative understanding of the mechanisms that control the isotopic compositions of biological methane. Our preliminary results show that M. acetivorans would be an ideal candidate for such research, which could help in understan","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"206 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136032838","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":"Genomic Approaches and Analyses of Slow-Growing Obligate Iron-Metabolizing Microbes","authors":"David Hsu, Abhiney Jain, Halle Kruchoski, Daniel Bond, Jeffrey Gralnick","doi":"10.3897/aca.6.e108172","DOIUrl":"https://doi.org/10.3897/aca.6.e108172","url":null,"abstract":"The biogeochemical cycling of iron is a vastly important process that has been a major factor defining life on Earth both before and after the Great Oxidation Event. While both abiotic and biotic factors contributing to the iron cycle have been studied for many years, the bulk of studies on iron metabolizing organisms has focused on a select few, easily manipulated model organisms. Recent discoveries have identified several unique and difficult to work with organisms from iron rich environments that survive solely on iron as either an electron acceptor or donor. The Fe(III)-reducing, Gram-positive Firmicute Metallumcola ferriviriculae MK1 was recently isolated from the Soudan Underground Mine in northern Minnesota from brine waters that intersect 2.7 Ga banded iron formations within the Canadian Shield. M. ferriviriculae MK1, which grows anaerobically using Fe(III)-citrate as its sole electron acceptor, is also mesophilic, spore-forming, culturable, and rich in multiheme cytochromes. Multiheme cytochromes are a well-established mechanism for Fe(III) reduction among the model Gram-negative microbes, such as Shewanella oneidensis and Geobacter sulfurreducens , but is poorly studied in Gram-positives. While the slow growth times of M. ferriviriculae MK1 make it difficult to study in the laboratory, the genome encodes homologs to multiheme cytochromes utilized by G. sulfurreducens for Fe(III) reduction. Specifically, two gene clusters (MK1_2258-2259 and MK1_2264-2265) each encode proteins homologous to the b -type cytochrome domain (60% and 61% sequence similarity, respectively) and c -type cytochrome domain (44.9% and 47.14%, respectively) of cbcL , which is used for reduction of mid-range redox potential acceptors in G . sulfurreducens and MK1_1670 is homologous to imcH (54.3% sequence similarity), which is used for higher redox potential acceptors. Additionally, the MK1 genome contains genes associated with sporulation, including genes encoding the master sporulation regulator spo0A , the peptidoglycan remodeling enzymes spoIID , spoIIP , and spoIIM , the spore morphogenesis protein spoIVA , and the small, acid-soluble spore proteins sspA , sspB , sspC , sspD , and sspF . Extraction and isolation of MK1 spores will facilitate evaluation of sporulation and germination conditions to shed light on a crucial preservation mechanism from an organism found in an environment with limited nutrients. Further evaluation into this novel organism can also give us insights into the microbial impacts on the iron cycle in the deep terrestrial biosphere. Another microbe of interest that was isolated from an iron-rich environment is the obligate Fe(II)-oxidizing Mariprofundus ferrooxydans PV-1, which was enriched from iron-rich mats associated with hydrothermal vents at the Kama’ehuakanaloa Seamount (previously Lo’ihi) in Hawaii. M. ferrooxydans PV-1 is a stalk-forming Fe(II)-oxidizing microbe and the first Zetaproteobacterium characterized. While M. ferrooxydans P","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135992790","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":"The Geochemical Habitats that Favored the Origin of Thermophilic Lineages ","authors":"Daniel Colman, Lisa Keller, Eva Andrade Barahona, Emilia Arteaga Pozo, Brian St. Clair, Alysia Cox, Eric Boyd","doi":"10.3897/aca.6.e108175","DOIUrl":"https://doi.org/10.3897/aca.6.e108175","url":null,"abstract":"Evidence in the fossil and isotopic records suggests that life inhabited hot springs by ~3.5 Ga. Further, phylogenetic evidence places Bacteria and Archaea from high temperature environments as among the earliest evolving lineages. Moreover, contemporary hot spring communities host an extensive level of biodiversity coinciding with extensive geochemical variation due to spatial and temporal heterogeneity in available oxidants and reductants generated by variable mixing of reduced volcanic and oxidized meteoric fluids. Thus, thermophilic archaeal and bacterial lineages have been co-evolving with their hydrothermal environments since early in the history of life and through dramatic changes in Earth’s geologic history. Yet, little is known of the environmental characteristics that enabled the extensive diversification of microbial life and their metabolic functionalities in these environments. To begin developing a framework to understand the environmental characteristics that enabled expansive microbial taxonomic and functional innovation in thermophilic lineages - coordinated geochemical, metagenomic, and phylogenetic analyses were conducted on 37 high-temperature Yellowstone National Park (YNP) hot spring ecosystems that spanned the range of geochemistry (pH ~1.5-10) in YNP springs. Considerable variation in dissolved solutes and gases were identified, consistent with spatial and temporal variation in the geological, geochemical, and hydrologic processes that influence the YNP hydrothermal system. Shotgun sequencing and bioinformatics analyses yielded 1,154 archaeal and bacterial metagenome-assembled-genomes (MAGs) from the 37 springs. Genomic diversity and metabolic functions encoded by the MAGs were not uniformly distributed among spring types based on geochemistry, with moderately acidic springs (pH 5-7) harboring the greatest overall diversity, despite these spring types being relatively rare among continental hydrothermal systems. Phylogenomic analyses of MAGs indicated that their divergence times (estimated by distance to phylogenetic roots) were variable, but highly associated with spring geochemistry. Specifically, spring types hosting the highest genomic, taxonomic, and functional diversity also predominantly harbored microbial lineages with the oldest inferred divergence times. In addition, MAG-encoded metabolic functions related to carbon fixation, methane, sulfur, iron, arsenic, hydrogen, and nitrogen metabolism were discretely distributed across spring geochemical types. The distribution of metabolic functions coincided with variation in spring geochemical parameters related to those metabolisms. For example, iron metabolism was most prevalent in acidic springs exhibiting the highest iron concentrations, gas metabolism was most prominent in moderately acidic springs that exhibited the highest dissolved gas concentrations, and arsenic metabolism was prevalent among alkaline pH springs where arsenic concentrations were highest. Lastly","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135993082","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":"Updates on microbial Iodine Cycling in snotty Biofilms of a prealpine Mineral Spring Cavern","authors":"Tillmann Lueders, Clemens Karwautz, Barbara Bekwinknoll, Felix Beulig, Baoli Zhu","doi":"10.3897/aca.6.e108241","DOIUrl":"https://doi.org/10.3897/aca.6.e108241","url":null,"abstract":"We have previously described the massive, methane-oxidizing microbial biofilms discovered in the cavern of an iodine-rich former medicinal spring in prealpine southern Germany (Karwautz et al. 2017). Next to up to 3000 ppm of methane in the cavern atmosphere, the mineral spring water can contain up to 23 mM of iodine, ~thousand-fold higher than in natural freshwaters. Since reactive iodine species can be toxic for microbes, the massive microbial growth in this cave is a fascinating phenomenon. We postulate that microbes capable of utilizing different iodine species should be prevalent in the cavern. Here, we present our recent work investigating the possible involvement of biofilm microbiota in either oxidative or reductive iodine cycling. Gradient tubes set up with iodide and oxygen as redox partners showed ample microbial growth and the formation of elemental iodine. Amplicon sequencing suggested different Alpha - ( Magnetospirillum spp.) and Gammaproteobacteria ( Aeromonas spp.) to be capable of iodide oxidation. Moreover, we address a possible iodate-dependent methane oxidation hosted within biofilm microbiota. Metagenomes allowed to assemble the MAGs of a novel member of the recently discovered anaerobic Methylomirabilota methanotrophs, Candidatus Methylomirabilis iodofontis . Its genetic repertoire included not only known markers of oxygenic denitrification and aerobic methane oxidation, but also of iodate respiration (Zhu et al. 2022). Our ongoing work will provide further evidence of the still largely uncharted iodine-cycling ecophysiologies of the biofilm microbiota of this unique microbe-dominated subsurface ecosystem.","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135993626","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":"Elevated bacterial endospores associated with thermogenic hydrocarbon seeps in deep sea sediments.","authors":"Jayne Rattray, Gretta Elizondo, Kathryn Sloan, Natasha Morrison, Martin Fowler, Daniel Gittins, Jamie Webb, D Campbell, Adam MacDonald, Casey Hubert","doi":"10.3897/aca.6.e108247","DOIUrl":"https://doi.org/10.3897/aca.6.e108247","url":null,"abstract":"Introduction and approach Bacterial endospore distributions in marine sediments are influenced by geological conduits providing routes for subsurface to surface microbial dispersal. To examine this phenomenon in more detail, endospore abundance was determined by quantifying the biomarker 2,6-pyridine dicarboxylic acid (dipicolinic acid or DPA) in 16 deep sea sediment cores from hydrocarbon prospective areas in the NW Atlantic Ocean. DPA is specific to endospore-forming bacteria from the phylum Firmicutes and constitutes a significant percentage of endospore dry weight. DPA is therefore a potential biomarker for sediment dwelling endospores and geological conduits. Piston cores (10), gravity cores (3) and box cores (3) were collected during two expeditions to the Scotian Slope in the NW Atlantic Ocean off the east coast of Canada aboard the CCGS Hudson in 2016 and 2018 (Campbell (2016), Campbell and Normandeau (2018), Campbell and MacDonald. (2016)). Sampling sites were 1970 to 2791 m water depth, with piston cores (n=3) ranging from 344 to 953 cmbsf and gravity cores (n=10) ranging from 43 to 739 cmbsf, box coring captured the top 25 cmbsf. To address the efficacy of DPA biomarker analysis as a tool for hydrocarbon seep location we established a modified Tb 3+ chelation method (Lomstein and Jørgensen (2012), Rattray (2021)). Sediment samples were extracted using acid hydrolysis, chelated with Tb3+ and analysed using HPLC fluorescence, measuring at 270 nm emission and 545 nm excitation. DPA concentrations were converted to Endospore numbers were calculated using 2.24 fmol DPA per endospore (Fichtel 2007), a conversion factor routinely used in other studies (Braun 2017, Gittins 2022, Heuer 2020, Lomstein 2012, Rattray 2022, Wörmer 2019, Lomstein and Jørgensen 2012). DPA concentrations were compared with measurements of over 250 different gaseous and liquid hydrocarbon compounds used to assess for the presence of thermogenic hydrocarbons. Results and discussion Samples and locations were assessed as being thermogenic hydrocarbon gas positive (stations 16-41, 18-07) or thermogenic hydrocarbon negative based on the abundance of C1-C5 hydrocarbons in sediments sampled from the same cores. Station 18-14 contained hydrocarbons from biogenic origin. Station 18-06 is the only site with higher endospore abundance but that was determined to be hydrocarbon negative. Deep water Scotian Slope sediment cores show high endospore abundance correlates with thermogenic hydrocarbon seeps (Fig. 1). Cores from locations lacking evidence for thermogenic hydrocarbons generally contained significantly lower endospore abundances, with the notable exception of site 18-06. This potential paleoenvironmental hydrocarbon seep site highlights the utility of a DPA proxy for potentially identifying ancient hydrocarbon seeps and investigating past geological systems. The association of high endospore abundances with thermogenic hydrocarbons and the quantity of gas expulsion points ","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136142729","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":"Assessing the Impact of Land Use and Land Cover on Water Quality: A Case Study of the Rákos Catchment in Hungary","authors":"Sahar Saeidi, Amir Mosallaei, Jalil Imani Harsini, János Grósz, István Waltner","doi":"10.3897/aca.6.e108160","DOIUrl":"https://doi.org/10.3897/aca.6.e108160","url":null,"abstract":"Water quality maintenance is a crucial goal in today's society due to the increasing demand for water resulting from urbanization and population growth. Surface water quality can be impacted by various sources, particularly land uses in the surrounding basin. Land use and land cover (LULC) influence several processes in the water cycle, including interception, infiltration, evapotranspiration, runoff, and water storage. LULC changes can have significant effects on local water resources, including water quantity and quality. Hungary, despite its abundance of freshwater sources, faces the challenge of pollution in most of its water bodies. This study focuses on the Rákos catchment in Hungary to monitor and analyze its water quality and the effects of land use and land cover on it. The Rákos stream flows through different land use areas, including residential, industrial, agricultural, forested, and mixed zones, which can influence water quality conditions, especially due to anthropogenic sources. Additionally, the stream receives water from communal wastewater treatment facilities. The study area was divided into eight sampling points, considering changes in land use. Water samples were analyzed for temperature, pH, electrical conductivity, dissolved oxygen, nitrite, nitrate, ammonium, phosphate, chlorophyll-a, and total cyanobacteria. The monitoring campaign commenced in November 2019 with biweekly data collection, and this paper covers the data collected until November 2021. To understand the relationship between land use and water quality, land use and land cover information from the Corine Land Cover datasets for 2018 was incorporated. Pearson's correlation analysis was performed to assess the correlations between LULC types and water quality parameters based on monthly and seasonal averages. The findings from the Pearson's correlation analysis provide valuable insights into the relationships between land use types and water quality parameters in the study area. The significant correlations observed highlight the influence of specific land use categories on water quality, emphasizing the need for effective land management strategies to protect and improve water resources. Heterogeneous agricultural areas demonstrated positive correlations with nitrite, ammonium, and total dissolved solids, suggesting that agricultural activities in these areas may contribute to elevated levels of these water quality parameters. The use of fertilizers and pesticides in agricultural practices can lead to increased nutrient and sediment runoff, which may explain the observed positive correlations. These findings underscore the importance of implementing best management practices in agricultural areas to minimize potential negative impacts on water quality. Pasture areas, on the other hand, exhibited negative correlations with nitrate, ammonium, phosphate, and total dissolved solids, suggesting that pasture land may have a filtering or buffering effect on these wat","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136114543","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":"Exploring Biomarker Signatures in Glaciovolcanic Environments: Implications for the Search for Life on Mars","authors":"Erin Gibbons, Richard Leveille, Greg Slater, Kim Berlo","doi":"10.3897/aca.6.e108122","DOIUrl":"https://doi.org/10.3897/aca.6.e108122","url":null,"abstract":"Glaciovolcanic systems, where hydrothermal heat interacts with ice, offer favorable conditions for life by providing liquid water, nutrients, and physicochemical gradients (Cousins and Crawford 2011). Despite significant climate change, evidence for glaciovolcanism is widespread through Mars’ history. Such sites may have offered refugia for life after Mars lost much of its surface water, representing some of the most recent habitable areas and promising sites to recover biomarkers. We examined a terrestrial glaciovolcanic site to study the indigenous biological community structure, the supporting physicochemical parameters, and the distribution of biomarkers within the geologic context. The insights will help refine Mars exploration of analogous sites. Method : We studied a partially subglacial hydrothermal area at the summit of the active Kverkfjöll volcano, Iceland. The heated ground has created a large ice-damned meltwater lake with shoreline hot springs, thermal streams, and mud pots of variable activity. We collected water and sediment samples aseptically across the breadth of features, including the lake (surface & depth). Samples were kept at -4°C. Environmental parameters were measured at each sample site. Sediment samples were split for mineralogical and organic analysis. Mineralogy was measured by X-ray Diffraction. Organic samples were freeze-dried and extracted with a Bligh & Dyer method (Bligh and Dyer 1959). Extracts were divided into hydrocarbons, neutral lipids, glycolipids, and phospholipid fatty acids (PLFA) with hexane, dichloromethane, acetone, and methanol. Gas Chromatography/Mass Spectrometry was used to analyze hydrocarbons and PLFA as fatty acid methyl esters. Results : Environmental : Fluids ranged from acidic to alkaline (pH 3-9), low to high temperature (8-87°C), and severely dysoxic to oxic (0.5-5 mg/L dissolved O). Mineralogy comprised a dioctahedral swelling clay, heulandite, and minor quartz, anatase, and pyrite. The assemblage suggests argillic-grade alteration at 100-140°C (Fulignati 2020), confirming that the glaciovolcanic conditions were within theoretical boundaries for life (<150°C (Merino et al. 2019)), and formed minerals capable of protecting organic matter (e.g., swelling clay). Lipids : PLFA are essential components of cell membranes and degrade rapidly upon cell death. PLFA profiles thus provide insight into the composition and distribution of the viable community. Results revealed a diversity of PLFA with low molecular weights and several bacterial-diagnostic structures, indicating an active prokaryote-dominated biosphere. Molecular patterns correlated (p<0.05) with pH, temperature, and oxygen, suggesting homeoviscous adaptations or community composition variations. In either case, microbes demonstrate adaptability to extreme conditions in glaciovolcanic settings. Hydrocarbons are inert and used as molecular fossils. We detected multiple patterns attributable to microbial biosynth","PeriodicalId":101714,"journal":{"name":"ARPHA Conference Abstracts","volume":"16 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":"135858493","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}