S(0) Globule Metabolism in Chlorobaculum tepidum: Interdisciplinary Studies of a Novel Microbe Mineral Interaction

智力优良元素硫，S(0)，是一种常见的化学物种，涉及广泛的环境和工业反应。S(0)在大多数条件下是无毒、相对惰性、不动的固体。它是黄石国家公园里的“黄色”，在农业上用作缓释肥料，也是工业过程中从废物中去除有毒硫化氢的理想最终产品。S(0)的循环是由微生物活动驱动的。总的来说，这个项目试图通过解决以下问题来为微生物-矿物相互作用提供新的见解：单个微生物如何既合成又降解不溶的无机化合物？该项目的模式系统是光养绿色硫磺细菌青绿杆菌。而一些微生物形成或消耗胞外矿物质，CBA。替匹石是不寻常的，因为它既从硫化氢中生成S(0)，又在没有硫化氢的情况下消耗S(0)。纳米成像、分析化学和分子生物学的工具将被应用于确定CBA是如何进行的。天冬青在形成和消费过程中与S(0)相互作用。该项目旨在确定S(0)形成和消费所需的特定基因产物。然后，它将解决这些基因产品如何为两个CBA量身定做。替彼杜姆和S(0)表面上进行了富有成效的互动。能量和养分的可获得性是确定微生物生态位和微生物群落在特定环境中成功与否的关键参数。绝大多数培养的微生物从可溶于水介质的化合物中获得能量和营养。然而，许多资源都被绑定为不溶矿物，比如S(0)。本项目中开发的对细胞与不溶矿物相互作用机制的理解将提供与其他微生物-矿物系统(即铁/锰氧化和还原细菌)的有益比较，并使我们能够区分独特和普遍的特征。更广泛的影响微生物-矿物相互作用的研究为在化学、生物学和环境科学方面培训学生和初级科学家提供了一个极好的机会。该项目将在项目期间为至少两名博士生、一名博士后学者和三名本科生提供跨学科培训。这包括细菌分子遗传学、“组学”技术、厌氧培养、纳米成像和元素分析技术方面的技术培训。代表不足的群体的参与将得到促进，因为国际和平协会作为国际教育、科学、文化和技术部(DGE-1144726)的联合公民协会，正在与当地的少数群体服务机构建立从本科生到研究生的过渡方案。该项目产生的成果和信息将通过每年吸引10,000名游客的特拉华大学海岸日、终身学习研讨会、科学咖啡馆S以及公众团体参观特拉华生物技术研究所向公众传播。这些公共互动的目标是赋予环境微生物作为有益的生物地球化学引擎的关键作用，而不仅仅是疾病的病原体。K-12教育工作者将特别成为PI和Co-PI参加“在职日”培训研讨会的对象。

Intellectual MeritElemental sulfur, S(0), is a common chemical species involved in a wide range of environmental and industrial reactions. S(0) is a non-toxic, relatively inert, immobile solid under most conditions. It is the "Yellow" in Yellowstone National Park, it is applied as a slow release fertilizer in agriculture, and it is the desired end product for industrial processes that remove toxic hydrogen sulfide from waste. The cycling of S(0) is driven by microbial activity. Broadly this project seeks to provide new insights into microbe-mineral interactions by addressing the following question:How does a single microbe both synthesize and degrade an insoluble inorganic compound? The model system for this project is the phototrophic green sulfur bacterium Chlorobaculum tepidum. While some microbes either form or consume extracellular minerals, Cba. tepidum is unusual as it both forms S(0) from hydrogen sulfide and consumes S(0) when hydrogen sulfide is not present. Tools of nanoscale imaging, analytical chemistry and molecular biology will be applied to identify how Cba. tepidum interacts with S(0) during its formation and consumption. The project seeks to identify specific gene products required for both S(0) formation and consumption. It will then address how these gene products tailor both Cba. tepidum and S(0) surfaces for productive interaction. The availability of energy and nutrients are critical parameters that define microbial niches and the success of microbial communities in a given environment. The vast majority of cultured microbes obtain energy and nutrients from compounds soluble in aqueous media. However, many resources are bound as insoluble minerals, like S(0). The understanding of mechanisms for cellular interactions with insoluble minerals developed in this project will provide an instructive comparison to other microbe-mineral systems (i.e. Fe/Mn oxidizing and reducing bacteria) and allow us to discriminate between unique and universal features. Broader ImpactsThe study of microbe-mineral interactions provides an excellent opportunity to train students and junior scientists at the interface of chemistry, biology, and environmental science. The project will provide interdisciplinary training for at least two Ph.D. students, one postdoctoral scholar and three undergraduates over the duration of the project. This includes technical training in bacterial molecular genetics, "omics" techniques, anaerobic culturing, and nanoscale imaging and elemental analysis techniques. The participation of under-represented groups will be facilitated by the PI's role as a Co-PI on an IGERT (DGE-1144726) that is establishing undergraduate-to-graduate bridge programs with local minority serving institutions. Results and information generated by this project will be disseminated to the public through the University of Delaware's Coast Day, which attracts 10,000 visitors each year, lifelong learning seminars, science cafés, and public group visits to the Delaware Biotechnology Institute. The goal of these public interactions is to impart the critical role of environmental microbes as beneficial biogeochemical engines and not solely agents of disease. K-12 educators will specifically be targeted by PI and Co-PI participation in "in service day" training seminars.