The impact of oceanic microbial communities on marine biogeochemistry now and in the future

海洋微生物群落对现在和未来海洋生物地球化学的影响

• 批准号: RGPIN-2021-04060
• 负责人: LaRoche, Julie
• 金额: $ 2.4万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=742848
• 关键词: impact; oceanic; microbial; communities; marine

The overarching goal of the proposed research program is aimed at understanding the response of the microbial community (collectively phytoplankton and other microbes) to increasing seawater temperature and decreasing nutrient inventory and how this will affect primary productivity in the Northwest Atlantic (NWA) and other under-sampled regions of the world's ocean. A multi-pronged approach engages established microbial observatories in the NWA, including weekly to annual sampling of in-shore stations (Bedford Basin), spring and fall missions on the Scotian Shelf (in collaboration with DFO), and yearly sampling in the Labrador Sea. The research builds on established international collaborations (GEOMAR, WHOI) and develops new ones (AWI, IUEM, CIIMAR), thereby linking to international time-series and ensuring interoperability of the observations. Extending the research on microbial community structure and function within the context of the NWA, the PI will transfer her expertise to the study of microbial communities associated with the aquaculture industry. The proposed research builds on previous work on diazotrophs and nitrogen fixation as well as their associated microbial communities. In recent years, it has become clear that non-photosynthetic microbes make up the bulk of the diazotroph diversity. It is important to assess the contribution and function of the non-photosynthetic diazotrophs in the context of their global cell metabolism and within their characteristic microbial community, in addition to their ability to fix nitrogen. In a recent breakthrough in the PI's laboratory, the isolation of a widely distributed heterotrophic diazotroph has led to characterization of the production of polyhydroxybutyrate (PHB) linked to the diazotrophic lifestyle, a compound used in the synthesis of biodegradable plastic. Further studies will use transcriptomic, proteomic, and metabolomic approaches to elucidate the metabolism of this microorganism. The proposed research will rely on established time-series platforms to carry out the following objectives: i) With the microbial observatory in the NWA, establish the current baseline and associated variability in the microbial community to characterize strategic locations in the NWA (Coastal embayment, Scotian Shelf, and Labrador Sea). This will serve to explore how microbial community composition and metabolic function respond to changes in environmental conditions. ii) Perform manipulative experiments on natural microbial communities and new microbial isolates, including N2-fixing microbes (diazotrophs), from the Scotian Shelf and the NWA. iii) Transfer the developed approaches and the knowledge gained from objectives (i) and (ii) to specific aquaculture settings in order to compare and contrast microbial communities of salmon aquaculture farms and those of the surrounding coastal areas including the Scotian Shelf.

拟议的研究计划的总体目标旨在了解微生物群落（集体浮游植物和其他微生物）对升高海水温度和降低营养库存的反应，以及这将如何影响西北大西洋（NWA）和其他世界海洋采样不足的西北大西洋（NWA）的主要生产率。一种多管齐下的方法与NWA建立了微生物观测站，包括每周一次的近岸工厂（贝德福德盆地），斯科舍省货架上的春季和秋季任务（与DFO合作）以及在拉布拉多海进行年度抽样。该研究以既定的国际合作（Geomar，Whoi）为基础，并开发了新的合作（AWI，IUEM，CIIMAR），从而与国际时间序列相关联并确保观察值的互操作性。在NWA的背景下，将有关微生物群落结构和功能的研究扩展，PI将其专业知识转移到与水产养殖业相关的微生物社区的研究中。拟议的研究基于重生营养和氮固定及其相关微生物群落的先前工作。近年来，很明显，非光合合成微生物构成了重18zotroph多样性的大部分。重要的是要在其全球细胞代谢和特征性微生物群落中评估非光合物质重生的贡献和功能，除了它们固定氮的能力。在PI实验室的最新突破中，分布广泛的异养无菌营养的分离导致了与重生营养性生活方式相关的多羟基丁酸（PHB）的产生，这是一种用于生物降解塑料合成的化合物。进一步的研究将使用转录组，蛋白质组学和代谢组方法来阐明这种微生物的代谢。拟议的研究将依靠既定的时间序列平台来执行以下目标：i）与NWA中的微生物天文台一起，建立微生物群落中当前的基线和相关的可变性来表征NWA（沿海胚胎，沿海胚胎，斯科舍省，苏格兰架子和拉布拉多海）的战略位置）。这将有助于探索微生物社区组成和代谢功能如何应对环境条件变化。 ii）从斯科舍省和NWA上进行自然微生物群落和新的微生物分离株（包括N2固定微生物（重18zotrophs））的操纵实验。 iii）将开发的方法以及从目标（i）和（ii）获得的知识转移到特定的水产养殖环境，以比较和对比鲑鱼水产养殖场的微生物群落以及周围沿海地区（包括斯科特式货架）的微生物群落。