Geomicrobial response to environmental stress-functional implications of identifying thresholds in anthropogenic gradients

地球微生物对环境胁迫的响应-识别人为梯度阈值的功能影响

• 批准号: RGPIN-2022-02939
• 负责人: Weisener, Christopher
• 金额: $ 2.19万
• 依托单位: University of Windsor
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=755167
• 关键词: Geomicrobial; response; environmental; stress; functional

Agricultural land and urban pressures on the terrestrial-freshwater interface can lead to increased stress on biota, poor water quality and can be an impediment to ecosystem health. A long-standing approach to ecosystem assessment uses biological integrity (BI) measures contrasting biological attributes of degraded environments to those of more desirable, minimally impacted ones. However, anthropogenic activity produces diverse materials that stress biota, salts, nutrients, hydrocarbons, metals, and xenobiotics. A critical knowledge gap is to identify measures of BI diagnostic of the key microbially-mediated transformations of those materials in sediment and water and determining whether how these processes can ameliorate the stress. The sediment/water interface plays an important role in biogeochemical cycles (e.g., P, N, S, C, Fe and Si) and water quality. Although this ecotone harbors a vast array of microbial taxa, their dominant functional characteristics and resilience to increasing environmental stress e.g., anthropogenic pressures, environmental extremes are largely unknown. For example, studies of eutrophication involving P and N sediment dynamics have focused on adsorption/desorption mechanisms associated with metal oxides and their redox transformations (e.g., nitrogen fixation, mineralization (decay), nitrification and denitrification). However, these measures can be system specific as the essential microbial component is a black box in modelling and conceptual characterization. Our approach to understanding microbial functional expression coupled with geochemical methods show clear connections between microbial community response to redox fluctuations and mineral dissolution in the presence of bacteria, which can lead to specific pathways of metal and nutrient release and explain how the bacteria benefit from this electron exchange metabolism. Using microbial and analytic techniques in laboratory and field-based programs, this hypothesis driven research program will expand our understanding of bacterial response to anthropogenic pressure in aquatic freshwater sediments. We will identify the mechanistic and functional roles of bacteria at the sediment water interface in transforming key materials of concern that characterize classes of stressed habitats. Results will be shared in a new omics database and used to refine models of biogeochemical cycling in stress impacted ecosystems and improve understanding of microbial heterotopic function. Maintaining sustainable freshwater resources is essential to Canada's socio-economic sustainability through agriculture, industry, people, and tourism. This program will document the critical role that bacteria play in controlling metal and nutrient dynamics in natural freshwater ecosystems subject to anthropogenic stress. By identifying key biomarkers of gene expression, we will advance the application of tool based open arrays for assessing contaminants in terrestrial and aquatic ecosystems.

农业用地和城市对陆地-淡水界面的压力可能导致生物群压力增加、水质恶化，并可能妨碍生态系统健康。生态系统评估的一种长期方法是使用生物完整性（BI）措施，将退化环境的生物属性与更理想的、受影响最小的环境的生物属性进行对比。然而，人类活动产生的各种物质对生物群、盐、营养物质、碳氢化合物、金属和外源物质造成压力。一个关键的知识差距是确定对沉积物和水中这些材料的关键微生物介导的转化进行 BI 诊断的措施，并确定这些过程是否可以减轻压力。沉积物/水界面在生物地球化学循环（例如 P、N、S、C、Fe 和 Si）和水质中发挥着重要作用。尽管这个生态交错带拥有大量的微生物类群，但它们的主要功能特征和对日益增加的环境压力（例如人为压力、极端环境）的恢复能力在很大程度上是未知的。例如，涉及磷和氮沉积物动力学的富营养化研究主要集中在与金属氧化物及其氧化还原转化（例如固氮、矿化（腐烂）、硝化和反硝化）相关的吸附/解吸机制。然而，这些措施可以是系统特定的，因为基本的微生物成分在建模和概念表征中是一个黑匣子。我们理解微生物功能表达的方法与地球化学方法相结合，表明微生物群落对氧化还原波动的反应与细菌存在下的矿物质溶解之间存在明确的联系，这可以导致金属和营养物释放的特定途径，并解释细菌如何从这种电子交换代谢中受益。在实验室和实地项目中使用微生物和分析技术，这一假设驱动的研究项目将扩大我们对水生淡水沉积物中细菌对人为压力的反应的理解。我们将确定沉积物水界面细菌在转化表征压力栖息地类别的关键材料方面的机制和功能作用。结果将在新的组学数据库中共享，并用于完善受压力影响的生态系统中的生物地球化学循环模型，并提高对微生物异位功能的理解。维持可持续的淡水资源对于加拿大农业、工业、人民和旅游业的社会经济可持续发展至关重要。该计划将记录细菌在控制受人为胁迫的自然淡水生态系统中的金属和营养动态方面发挥的关键作用。通过识别基因表达的关键生物标志物，我们将推进基于开放阵列工具的应用，以评估陆地和水生生态系统中的污染物。