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.
{"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}
Angela Smirnova, Peter Dunfield, Chantel Furgason, Andriy Sheremet, Felix Nwosu, Joel Dacks
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.
阿尔伯塔省东北部阿萨巴斯卡地区的沥青石油开采占加拿大经济的很大一部分。然而，从地面开采的油砂矿石中提取石油的过程会导致各种环境问题，包括对陆地面积和野生动物栖息地的干扰，以及产生大量含有许多环境关注化合物的流动尾矿。大多数油砂作业的土地复垦策略都建议建造尾坑湖(EPL)来容纳和生物降解尾矿，最终成为当地的集水区。我们利用16S/18S rRNA基因扩增子和元基因组测序技术，从2015年至2021年，在加拿大油砂的第一个全规模试点EPL (Base Mine Lake, BML)(图1)中监测原核和真核生物群落，并将其与两个活跃尾矿库(Mildred Lake Setting Basin, MLSB)和西南矿坑(Southwest in- pit, SWIP)的群落进行比较，以及来自更自然的淡水水体Beaver Creek Reservoir (BCR)的群落进行比较。BML的α多样性介于活性尾矿库和天然湖泊之间，但随时间、深度和季节变化很大。BML的微生物群落既不像淡水湖，也不像活跃的尾矿群落，尽管这两种微生物群落每年都会发生结构变化，而2021年是影响最深远的一年。此外，BML中的代谢功能每年也会发生变化，其中光合作用相关基因的变化最为显著。在BML中发现的原生生物之间的时间变化特征是浮游植物种类的富集:隐单胞菌，Mychonastes, Trebouxiophyceae和Dinobryon，细菌属之间的富集是常见的淡水湖物种或浮游细菌:Ca。Fonsibacter, Sporichthyaceae, Ca.浮游生物，microbacteraceae ML602J-51, Ilumatobacteraceae CL500-29组。网络分析确定了浮游植物和浮游细菌之间潜在的微生物联合体。具有流线型基因组的异养细菌可能通过趋化行为清除光养生物产生的代谢物和其他化合物，从而克服营养不足的限制。该联合体的形成可作为油砂尾矿库复垦过程的生物标志。
{"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}
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
距离衰减关系是生物地理学和空间生物多样性的一个核心概念，描述了两个不同实体如何随着它们之间距离的增加而减少相似性。群落相似性随地理距离的衰减是由多种因素驱动的，如基因漂变、环境选择和突变随时间的积累。虽然距离衰减关系已经被认识了几十年，但在某些情况下，某些物种和群落的生物地理格局不能用这种关系来预测。在这个项目中讨论的例子是在永久寒冷的深海沉积物中发现的嗜热内孢子形成细菌。嗜热内生孢子(热孢子)通常在深海海底发现，这是一个永久寒冷的环境，不支持它们的代谢活动(Hubert et al. 2009)。热孢子是由一些嗜热细菌产生的代谢休眠状态，其最佳生长温度在40°C至70°C之间。有证据表明，这些喜热细菌起源于深层地下，并通过海洋地壳的地质特征，包括高温轴向系统的地流体通量和天然碳氢化合物渗漏，向上输送到深海(Gittins et al. 2022)。由于内生孢子能够存活数千年并抵抗各种物理化学压力，它们可以远距离分散，而不受选择、漂变或突变等变化因素的影响(Gittins et al. 2022;图1)因此，这些热孢子有可能挑战距离衰减关系，并表现出独特的生物地理模式。本研究使用深海斯科舍坡沉积物的岩心对碳氢化合物渗漏处及其周围沉积物岩心中的内生孢子进行了量化。考虑到量化特定内生孢子群(例如，嗜热菌而不是嗜中菌)的挑战，可以使用高温萌发试验来跟踪海洋沉积物样品中孢子萌发和生长时信号的指数增长。明显的指数增长可归因于萌发后生长阶段萌发的热孢子的不同种群，并通过测量硫酸盐还原率(使用放射性标记的35 SO 4)、菌株特异性定量PCR (qPCR)和荧光原位杂交(FISH)进行监测(Rezende等，2017)。这些测量揭示了生长动态，可以使用指数函数估计初始细胞数。这些方法正在应用于通过远程操作的车辆在深海碳氢化合物渗漏的不同距离上通过推取芯获得的样品，以测试不同热孢子丰度梯度的存在。目前的结果已经表明，在离渗漏点不同距离的地点，热孢子的丰度是不同的。深海洋流对热孢子扩散的定量跟踪为研究它们的分布和在更偏远栖息地定居的潜力提供了一个极好的机会，提高了对我们星球上微生物多样性和生物地理学的理解。通过研究热孢子及其与深海和深地下地球物理特征的相互作用，本研究旨在挑战物种形成随距离发生的经典观点，并为微生物生物地理学的主题提供新的视角。支持嗜热内生孢子地下起源的证据，以及提出的它们的扩散和分布模型，将有助于提高对生态学和地质学的综合理解，以及它们在微生物领域的交集。
{"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}
Jonathan Gropp, Markus Bill, Daniel Stolper, Dipti Nayak
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
几乎所有的生物甲烷都是由一组叫做产甲烷古菌(或产甲烷菌)的微生物产生的。产甲烷菌可以使用多种底物，如h2 + CO 2，醋酸酯和甲基化化合物，用于产甲烷。先前的研究表明，产甲烷菌产生的甲烷的稳定碳和氢同位素组成可以根据环境中的底物组成和浓度发生巨大变化。例如，环境中h2的浓度对氢营养产甲烷(利用h2作为电子供体将CO 2还原为甲烷)产生的甲烷的同位素组成有重大影响(Valentine et al. 2004, Penning et al. 2005)。虽然有大量关于不同基质和不同条件下甲烷同位素特征的经验数据，但控制这些值的生理和分子特征尚未得到很好的理解。为了解决这个问题，我们使用代谢多样化和遗传易处理的甲烷菌Methanosarcina acetivorans作为模型系统来揭示控制甲烷稳定体积同位素组成(即13c / 12c和D/H比率)的关键细胞过程，以及“团块”13ch3 D和12ch2 d2同位素的分布。产甲烷菌m.a evtivorans生长在多种化合物上，如醋酸盐、甲醇、甲胺和甲基硫化物。我们发现甲基化途径(甲醇和三甲胺)和醋酸化途径具有大而相似的初级氢同位素效应(α为~0.45)。这些数据与之前的发现形成对比，表明甲烷和h2o之间存在少量同位素交换(Valentine et al. 2004, Gruen et al. 2018)。首先关注甲基化营养途径，我们生成了甲基化营养途径中两个关键酶的突变体:a)催化甲烷生成最后一步的甲基辅酶M还原酶(Mcr)和b)催化甲醇甲基化甲烷生成第一步的甲基转移酶(Mta)。Mcr表达降低的突变体与野生型相比，氢同位素效应没有明显变化，这证实了最初观察到的最小H 2 O-CH 4氢同位素交换。其中一个Mta突变体只表达一个特定的甲基转移酶亚型，相对于其他亚型，其碳同位素效应较小(α为~1.074 vs ~1.080)。由于同工异构体被认为在结构上是相同的，不同的同位素效应可能是由于每个同工异构体的不同表达或不同的动力学性质造成的。通过将我们的遗传方法与传统的高分辨率同位素分析方法相结合，我们的目标是对控制生物甲烷同位素组成的机制进行定量理解。我们的初步结果表明，m.a etivorans将是这类研究的理想候选者，这将有助于了解过去、现在和未来地球自然环境中产甲烷菌的生理学。
{"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}
David Hsu, Abhiney Jain, Halle Kruchoski, Daniel Bond, Jeffrey Gralnick
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
{"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}
Daniel Colman, Lisa Keller, Eva Andrade Barahona, Emilia Arteaga Pozo, Brian St. Clair, Alysia Cox, Eric Boyd
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
{"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}
Tillmann Lueders, Clemens Karwautz, Barbara Bekwinknoll, Felix Beulig, Baoli Zhu
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.
我们之前已经描述了在德国南部前高山富含碘的前药用泉的洞穴中发现的大量甲烷氧化微生物生物膜(Karwautz et al. 2017)。在洞穴大气中，除了高达3000 ppm的甲烷外，矿泉水的碘含量可达23毫米，比天然淡水高出数千倍。由于活性碘对微生物是有毒的，所以这个洞穴里大量的微生物生长是一个令人着迷的现象。我们假设能够利用不同碘种的微生物应该在洞穴中普遍存在。在这里，我们介绍了我们最近的工作，研究生物膜微生物群在氧化或还原性碘循环中的可能参与。以碘和氧为氧化还原伙伴的梯度管显示了充足的微生物生长和元素碘的形成。扩增子测序表明不同的α -(磁螺旋藻)和γ -变形菌(气单胞菌)具有氧化碘的能力。此外，我们解决了可能的碘依赖甲烷氧化宿主在生物膜微生物群。宏基因组允许组装最近发现的厌氧甲基化菌中一个新成员的mag，候补甲基化菌。其遗传库不仅包括已知的氧反硝化和有氧甲烷氧化标记，还包括碘酸盐呼吸标记(Zhu et al. 2022)。我们正在进行的工作将为这个独特的以微生物为主的地下生态系统的生物膜微生物群的碘循环生态生理学提供进一步的证据。
{"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}
Jayne Rattray, Gretta Elizondo, Kathryn Sloan, Natasha Morrison, Martin Fowler, Daniel Gittins, Jamie Webb, D Campbell, Adam MacDonald, Casey Hubert
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
{"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}
Sahar Saeidi, Amir Mosallaei, Jalil Imani Harsini, János Grósz, István Waltner
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
{"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}
Erin Gibbons, Richard Leveille, Greg Slater, Kim Berlo
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
在冰火系统中，热液与冰相互作用，通过提供液态水、营养物质和物理化学梯度，为生命提供了有利的条件(Cousins and Crawford 2011)。尽管气候发生了重大变化，但冰火山作用的证据在火星历史上广泛存在。这些地点可能在火星失去大部分地表水后为生命提供了避难所，代表了一些最近的可居住区域和有希望恢复生物标记的地点。研究了陆相冰火遗址的原生生物群落结构、支持的物理化学参数和生物标志物在地质背景下的分布。这些见解将有助于改进火星上类似地点的探索。方法:我们研究了冰岛Kverkfjöll活火山山顶的部分冰下热液区。加热的地面形成了一个巨大的冰雪融水湖，有岸边的温泉、热流和各种活动的泥盆。我们在包括湖表面在内的整个地形上无菌地收集了水和沉积物样本。深度)。样品保存在-4°C。在每个采样点测量环境参数。沉积物样品进行了矿物学和有机分析。矿物学用x射线衍射测定。有机样品冻干后用Bligh &代尔方法(Bligh and Dyer 1959)。萃取物分为烃类、中性脂类、糖脂类和磷脂脂肪酸(PLFA)，有己烷、二氯甲烷、丙酮和甲醇。采用气相色谱/质谱法分析烃类和PLFA作为脂肪酸甲酯。环境:流体范围从酸性到碱性(pH值3-9)，低温到高温(8-87°C)，严重缺氧到缺氧(0.5- 5mg /L溶解O)。矿物学包括二八面体膨胀粘土、榴辉石，以及少量石英、锐钛矿和黄铁矿。该组合表明100-140°C的泥质级蚀变(Fulignati 2020)，证实了冰川火山条件在生命的理论边界内(<150°C (Merino et al. 2019))，并形成了能够保护有机质的矿物(例如膨胀粘土)。脂质:PLFA是细胞膜的基本成分，在细胞死亡时迅速降解。因此，PLFA概况可以深入了解可行群落的组成和分布。结果显示PLFA具有低分子量和多种细菌诊断结构的多样性，表明一个活跃的原核生物主导的生物圈。分子模式与pH值、温度和氧气相关(p<0.05)，表明均粘适应或群落组成变化。在任何一种情况下，微生物都表现出对冰川火山环境极端条件的适应性。碳氢化合物是惰性的，用作分子化石。我们发现了多种归因于微生物生物合成的模式，包括蓝藻中丰富的c17(直支)诊断;高浓度的短链正构烷烃/烯烃双链(< c22)，具有均匀的碳偏好(CPI<1)，表明不同的微生物输入;以及具有微生物异养特征的洗脱参数的狭窄未解析复杂混合物(Finkel et al. 2023)。偶数烷烃/烯烃对的模式几乎没有报道，并提供了对稀有烃分布的见解。有趣的是，碳氢化合物和PLFA的模式并不一致。因此，PLFA不是碳氢化合物的重要来源，我们建议直接微生物合成占主导地位。这一假设的意义将在古生物重建的背景下讨论。结论:我们的遗址为不同的生命模式和适合有机保存的矿物组合提供了一系列的物理化学生态位。应该探索火星上类似的地点，但需要做更多的工作来了解碳氢化合物来源的保存偏差和解释的含义。
{"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 (&lt;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&lt;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}
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