Collaborative Research: Quantifying the role of microbial extracellular vesicles in marine dissolved organic matter production and consumption

合作研究：量化微生物细胞外囊泡在海洋溶解有机物生产和消耗中的作用

• 批准号: 2044346
• 负责人: Krista Longnecker
• 金额: $ 28.28万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2044346&HistoricalAwards=false
• 关键词: Collaborative; Research; Quantifying; role; microbial

Microbial production and consumption of organic carbon play critical roles in the marine food web and global carbon cycling. Bacteria release organic matter in a variety of chemical forms and in diverse contexts, ranging from individual molecules to small aggregates and larger biological particles. In recent years we have come to understand that most, if not all, marine microbes release nanoscale structures called extracellular vesicles from their surfaces. These discrete particles, which are abundant in the oceans, are capable of transporting multiple classes of organic molecules between organisms and can serve as a potential nutrient source for other microbes. Extracellular vesicles thus represent a potentially important component of marine microbial food webs, but the magnitude and dynamics of this contribution are unknown. Further, the packaging of material within vesicles may influence the accessibility of this organic material as compared with truly ‘dissolved’ substances to different groups of marine organisms, potentially biasing nutrient exchanges. Broader impacts of this work is providing hands-on research experiences for female undergraduate students - including those from groups historically underrepresented in STEM fields - and training in data analysis tools.The goal of this project is to advance the understanding of the role that extracellular vesicles play in marine dissolved organic carbon pools and microbial food webs. To determine the contribution of vesicles to organic matter release by marine microbes, the investigators are quantifying the fraction of excreted carbon and nitrogen associated with vesicles released by multiple marine cyanobacteria and heterotrophs. The project is examining how vesicles are ‘consumed’ by heterotrophs to calculate a mass balance of vesicle utilization and produce detailed gene expression data to explore how cells respond to the presence of vesicles. Finally, experiments with coastal and oligotrophic marine communities are providing insights into which organisms utilize vesicles in the field, and whether they are broadly accessible to all microbes or are instead preferentially consumed by a subset of microbes. Collectively, these experiments are opening up a new area of research into the mechanisms underlying the microbial loop and provide foundational insights into the roles of extracellular vesicles in ocean ecosystems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

微生物生产和消耗有机碳在海洋食物链和全球碳循环中发挥着关键作用。细菌以各种化学形式和不同的环境释放有机物，从单个分子到小聚集体和较大的生物颗粒。近年来，我们逐渐了解到，大多数海洋微生物(如果不是所有的话)都会从它们的表面释放被称为细胞外小泡的纳米级结构。这些离散的颗粒在海洋中大量存在，能够在有机体之间运输多种有机分子，并可以作为其他微生物的潜在营养来源。因此，胞外小泡是海洋微生物食物网的一个潜在的重要组成部分，但这种贡献的大小和动态尚不清楚。此外，与真正“溶解”的物质相比，囊内物质的包装可能会影响这种有机物质对不同海洋生物群体的可及性，从而潜在地影响营养物质的交换。这项工作的更广泛影响是为女本科生提供实践研究经验--包括那些来自STEM领域历史上代表性不足的群体--并提供数据分析工具培训。该项目的目标是促进对细胞外小泡在海洋溶解有机碳库和微生物食物网中所起作用的理解。为了确定囊泡对海洋微生物释放有机物的贡献，研究人员正在量化与多种海洋蓝藻和异养生物释放的囊泡相关的排泄碳和氮的比例。该项目正在研究囊泡是如何被异养生物“消耗”的，以计算囊泡利用的质量平衡，并产生详细的基因表达数据，以探索细胞如何对囊泡的存在做出反应。最后，对沿海和低营养海洋群落的实验正在提供关于哪些生物利用该领域中的小泡的洞察，以及这些小泡是否广泛地被所有微生物获取，或者相反地被部分微生物优先消耗。总体而言，这些实验开辟了微生物环路潜在机制的新研究领域，并为细胞外小泡在海洋生态系统中的作用提供了基础性的见解。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。