MIP: Interactions Between Archaea, Bacteria and their Viruses in the Anoxic Sediments of a Modern Evaporative Basin: Salton Sea, CA

地球上的许多生态系统缺乏呼吸所需的氧气，也没有多细胞生命。这种环境的主要例子是覆盖世界各地海洋和湖底的沉积物。这种环境从海底延伸到几英里深，覆盖了地球表面近四分之三的面积。尽管条件恶劣，但这些环境中蕴藏着大量的生命有机体。三大类生物在这里繁衍生息：细菌、古生菌和病毒。这三种生命形式之间的相互作用并不为人所知，这是本研究项目的重点。具体地说，这项研究的目标是确定这三个类群的丰度、分布和活动如何与不断变化的环境条件相关。需要检验的主要假设是，古生菌是单细胞有机体的一个谱系，通常与恶劣的环境有关，当条件导致饥饿和能量压力时，它能适应在竞争中击败细菌。这项研究将在加利福尼亚州的索尔顿海进行，并将使用分子生物学和地球化学方面的最先进工具。在索尔顿海的一磅沉积物中，大约存在1000亿种细菌和古生菌，感染它们的病毒数量大约是它们的十倍。该项目旨在区分细菌、古生菌及其病毒在其环境背景下的生态作用和相关性。到目前为止，缺乏管理这些群体相互作用的广泛原则，对哪些病毒感染哪些微生物知之甚少。这项研究将确定不同的单细胞生物体群体与它们的病毒之间的无数关系，并可能进一步区分关键群体的广泛生态作用。这项研究的时机至关重要，因为南加州迅速增长的人口正在迫切要求将大量水资源从沙漠农业转移到城市使用。索尔顿海是一个终端盆地，其几乎所有的水都来自农业径流；拟议的水输入速率的变化将导致索尔顿海的水量和盐度(从而导致生物地球化学和生态)的戏剧性变化。虽然索尔顿海的确切命运尚不确定，但可以预料到重大变化--显然有必要研究这一环境中的新型微生物。这项研究的直接影响包括对本科生和研究生的培训和教育，以及对普通公众的宣传。研究生和本科生将被纳入拟议的领域和实验室研究的所有方面。每年大约有20名本科生因将索尔顿海作为本科生实地研究课程的学习地点而受到影响。这项工作中与社会相关的发现将通过演讲、参加公共论坛和创建项目网站向公众传达。

Many ecosystems on earth lack oxygen to breath and are devoid of multicellular life. The prime example of such an environment is the sediment covering ocean and lake bottoms throughout the world. Extending from the sea floor to several miles deep this environment covers nearly three quarters of Earth's surface. Despite the harsh conditions these environments harbor tremendous numbers of living organisms. Three major classes of organisms thrive here: Bacteria, Archaea and viruses. The interactions between these three forms of life are not well known and are the focus of this research project. Specifically the goal of this research is to determine how the abundance, distribution and activity of these three groups relate to changing environmental conditions. The primary hypothesis to be tested is that the Archaea, an lineage of single-celled organisms often associated with harsh environments, are adapted to out-compete Bacteria when conditions lead to starvation and energy stress. This research will be performed at the Salton Sea, CA and will employ state-of-the-art tools in molecular biology and geochemistry. In one pound of sediment from the Salton Sea there exist approximately 100 billion Bacteria and Archaea and approximately ten times as many viruses to infect them. This project is designed to differentiate the ecological roles and relatedness of Bacteria, Archaea and their viruses within the context of their environment. To date, broad principles governing the interactions of these groups is lacking, and little is known of which viruses infect which microbes. This research will determine the myriad of relationships between the diverse groups of single-celled organisms and their viruses, and may further distinguish the broad ecological roles of key groups. The timing for this research is critical as the rapidly expanding population of southern California is pressing for major water transfers away from desert agriculture to urban uses. The Salton Sea is a terminal basin and receives nearly all its water from agricultural runoff; proposed changes to the rate of water input will lead to dramatic changes in volume and salinity (and thus biogeochemistry and ecology) of the Salton Sea. While the exact fate of the Salton Sea is uncertain, major changes can be expected - there is a clear need to study the novel microbes of this environment. Direct impacts of this research include the training and education of undergraduate and graduate students as well as outreach to the general public. Graduate and undergraduate students will be incorporated into all aspects of the proposed field and laboratory research. Approximately twenty undergraduate students will be impacted each year by using the Salton Sea as a study site for an undergraduate field studies course. Socially-relevant findings from this work will be relayed to the public through presentations, participation in public forums, and the creation of a project website.