Collaborative Research: Microbial Dynamics on Marine Snow Particles

合作研究：海洋雪颗粒的微生物动力学

• 批准号: 0352127
• 负责人: George Jackson
• 金额: $ 9.24万
• 依托单位: Texas A&M Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2008-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0352127&HistoricalAwards=false
• 关键词: Collaborative; Research; Microbial; Dynamics; Marine

Marine snow fluxes sequester carbon to the deep ocean, significantly buffering the greenhouse effect. In response to continuing global warming, large-scale ocean fertilization has been proposed as a way to enhance marine snow fluxes and remove extra atmospheric CO2. Marine snow particles harbor high densities of bacteria and other microbes, whose activities modify the physical and chemical characteristics of the particles. Understanding these processes is critical to predicting the fate of marine snow fluxes in the ocean. This project is aimed at a mechanistic understanding of the microbial dynamics on marine snow particles, using an innovative approach of combining experiments, observations and modeling. This project is 1) characterizing the time-dependent microbial dynamics on marine snow particles, 2) investigating how different biotic and abiotic factors modify the dynamics, and 3) developing mathematical models to quantitatively describe such dynamics. Lab-generated diatom aggregates are being used to test encounter models for predicting the rate at which bacteria colonize marine snow. Agar-aggregates are being used to examine bacterial chemosensory response to marine snow chemicals, and the effects of the bacterial physiological status on the colonization process. Predator-prey dynamics on snow particles are being investigated by grazing experiments with bacterivorous protists. Field studies are following the changes in bacterial colonization behavior, size and morphology of natural marine snow and the associated microbes during the course of an algal bloom. Laboratory and field observations are being used to test and expand colonization models in order to describe microbial dynamics on marine snow based on hydrodynamics, microbial behavior, growth and interspecific interactions. These models are being integrated with coagulation models to study how marine snow formation coupled with microbial dynamics affects marine snow and carbon fluxes in the water column. This project is extending the existing collaborations between VIMS, TAMU and three outstanding European research institutions. Graduate research training and education are integral parts of the project. To promote ethnic diversity and leadership training in marine sciences, minority undergraduates are being recruited through a new internship program DREAMS to participate in the project and gains hands-on research experience. The PIs are developing education materials for the general public with focus on global warming, ocean-climate interactions and ocean fertilization. These materials are being implemented by DREAMS interns in their outreach activities that target grade school students and teachers, allowing them to establish themselves as future leaders in climate issues.

海洋雪通量将碳封存到深海，显着缓冲温室效应。为了应对持续的全球变暖，大规模海洋施肥已被提议作为增强海洋雪通量和去除大气中额外二氧化碳的一种方法。 海洋雪颗粒含有高密度的细菌和其他微生物，它们的活动改变了颗粒的物理和化学特性。了解这些过程对于预测海洋雪通量的命运至关重要。该项目旨在采用实验、观察和建模相结合的创新方法，从机理上理解海洋雪颗粒的微生物动力学。 该项目的目的是 1) 表征海洋雪颗粒上随时间变化的微生物动力学，2) 研究不同的生物和非生物因素如何改变动力学，3) 开发数学模型来定量描述这种动力学。 实验室生成的硅藻聚集体被用来测试遭遇模型，以预测细菌在海洋雪中定殖的速度。琼脂聚集体用于检查细菌对海洋雪化学物质的化学感应反应，以及细菌生理状态对定植过程的影响。 正在通过食菌原生生物的放牧实验来研究雪颗粒上的捕食者-猎物动力学。 实地研究正在跟踪藻华过程中细菌定植行为、天然海洋雪的大小和形态以及相关微生物的变化。实验室和现场观察被用来测试和扩展定植模型，以便根据流体动力学、微生物行为、生长和种间相互作用来描述海洋雪上的微生物动力学。这些模型正在与凝结模型相结合，以研究海洋积雪的形成与微生物动力学如何影响水体中的海洋积雪和碳通量。该项目正在扩展 VIMS、TAMU 和三个欧洲杰出研究机构之间的现有合作。研究生研究培训和教育是该项目的组成部分。为了促进海洋科学领域的种族多样性和领导力培训，通过新的实习计划“梦想”招募少数民族本科生参与该项目并获得实践研究经验。项目负责人正在为公众开发教育材料，重点关注全球变暖、海洋与气候相互作用和海洋肥化。这些材料由 DREAMS 实习生在针对小学生和教师的外展活动中使用，使他们能够成为气候问题的未来领导者。