CAREER: Fundamental cell-mineral-redox interactions in the sulfur system

更好地理解氧化还原活性元素，如硫和铁，是影响海洋过渡等问题的关键，通过深时间，酸性气体和石油演化，热液化学和生命起源，铁向海洋的供应，工业脱硫，农业硫循环和金属流动性。数十亿年来，微生物一直是硫循环的潜在重要部分（约翰斯顿等人，2005; Mojzsis等人，2007），但微生物与元素硫之间的许多基本相互作用尚不清楚。要进一步了解这些系统的行为，需要深入研究细胞之间的详细相互作用（细菌，古细菌和真核生物），矿物质（特别是纳米颗粒）和水化学（特别是氧化还原物种形成）。元素硫以本体相和纳米颗粒相存在，并且可以通过用作电子受体、供体，或者在分离的情况下基本上两者都有。溶解的硫物质也与元素硫相互作用，并且这些物质还可以与金属，最重要的是铁反应。微生物必须溶解元素硫以代谢它，但是这种矿物质与已经充分研究了微生物-矿物质相互作用的其他矿物质（例如氧化铁矿物质）根本不同（例如埃尔南德斯和纽曼，2001; Childers等人，2002; Burgon等人，2003; Lovley，2008;纽曼，2008）。增溶元素硫可以通过与有机配体相互作用或通过与其他硫物质相互作用形成新的可溶性中间体如多硫化物来实现。研究人员建议开发一种综合原位分析能力，在现场和实验室测试中研究硫形态和元素硫矿物学，以解决以下假设：元素硫的大小和表面特征是控制许多环境中生物和非生物反应中硫循环的关键成分。硫系统中基本细胞-矿物质-氧化还原相互作用的进展提供了一个机会，可以整合一些令人兴奋的教育经验，让利益相关者和健康，政策，和法律的领域的研究目标，将产生价值的硫基微生物和元素循环随着时间的推移和环境相关系统的广泛研究的变革性见解。硫的种类和矿物质受到许多已知生物的重要影响，但对元素硫粒度/特征和氧化还原形态的详细程度从未应用过。当比较来自多年研究详细的氧化铁-微生物相互作用的丰富信息时（纽曼，2008），对涉及硫的基本微生物-矿物-氧化还原相互作用的详细研究可能会产生关键的新见解。通过这些硫系统研究获得的知识的应用可以应用于对影响人类健康问题的类似细胞-矿物质-氧化还原相互作用的更广泛思考。这为促进培训科学家与非科学公众交流结果提供了机会，并为利用矿物学，地球化学和微生物信息解决石棉矿物暴露，地下水砷污染和硒毒性等问题的医疗专业人员，政策制定者和法律的专业人员提供培训。将开发一系列课程和专业研讨会，以及一系列说明基本细胞-矿物-氧化还原相互作用的学习模块，让学生和专业人员参与地球化学，矿物学和微生物数据如何收集，评估，评估和辩论的实践经验，以获得可靠的信息。利益攸关方参与科学数据收集、评估和辩论的做法，并结合对具有更好沟通技能的科学家的培训，不仅是科学家培养方面的进步，也是与这些科学家一起工作的专业人员培养方面的进步。

Greater understanding of redox-active elements like sulfur and iron are key in the processes that affect problems such as ocean transitions through deep time, sour gas and oil evolution, hydrothermal chemistry and the origins of life, the supply of iron to the sea, industrial desulfurization, agricultural sulfur cycling, and metal mobility. Microorganisms have been a potentially important part of sulfur cycling for billions of years (Johnston et al., 2005; Mojzsis et al, 2007), yet many of the fundamental interactions between microorganisms and elemental sulfur are not understood. Advancing our understanding of how these systems behave requires delving into the detailed interactions between cells (bacterial, archaeal, and eukaryotic), minerals (especially nanoparticles), and water chemistry (especially redox speciation).Intellectual Merit: Elemental sulfur occurs as bulk and nanoparticulate phases and can be utilized by microorganisms for all 3 major catabolic paths through use as an electron acceptor, donor, or essentially both in the case of disproportionation. Dissolved sulfur species also interact with elemental sulfur, and those species can additionally react with metals, most importantly iron. Microorganisms must solubilize elemental sulfur in order to metabolize it, but this mineral is fundamentally different from other minerals where microbe-mineral interactions have been well studied, such as iron oxide minerals (for example Hernandez and Newman, 2001; Childers et al., 2002; Burgon et al., 2003; Lovley, 2008; Newman, 2008). Solubilizing elemental sulfur can be accomplished through interaction with organic ligands or through interactions with other sulfur species to form new soluble intermediates such as polysulfides. Investigator proposes to develop a combined in situ analytical capability to investigate sulfur speciation and elemental sulfur mineralogy in field and laboratory tests to address the following hypothesis: The size and surface character of elemental sulfur is a key component controlling sulfur cycling in biotic and abiotic reactions in many environments.Broader Impacts: Advances in fundamental cell-mineral-redox interactions in the sulfur system provide an opportunity to integrate some exciting educational experiences to engage stakeholders and professionals in health, policy, and legal fields with research goals that will yield transformative insights of value to the broad study of sulfur-based microorganisms and element cycling through time and in environmentally relevant systems. Sulfur species and minerals are importantly affected by a number of known organisms, but the level of detail proposed for elemental sulfur particle size/character and redox speciation has never been applied. When comparing the wealth of information that has come from years of investigating detailed iron oxide-microbe interactions (Newman, 2008), a detailed investigation of fundamental microbe-mineral-redox interactions involving sulfur may yield critical new insights. The application of the knowledge gained through these investigations of the sulfur system can be applied to broader thinking about similar cell-mineral-redox interactions that affect problems of human health. This opens an opportunity to advance the training of scientists to communicate results with the non-scientific public, and provide training to the medical professionals, policymakers, and legal professionals that utilize mineralogical, geochemical, and microbial information in addressing problems such as asbestos mineral exposure, groundwater arsenic contamination, and selenium toxicity. A series of classes and professional workshops will be developed, alongside a series of learning modules illustrating fundamental cell-mineral-redox interactions, to engage students and professionals in hands-on experiences of how geochemical, mineralogical, and microbial data is gathered, assessed, evaluated, and debated to arrive at reliable information. The participation of stakeholders in the practice of scientific data collection, evaluation, and debate integrated with the training of scientists with better communication skills represents not only an advance in the preparation of scientists, but an advance also in preparing professionals who will work with those scientists.