Probing Korachaeal ecophysiology via statistical analysis of quantitative molecular and geochemical data: A RIDGE2000 postdoctoral proposal

本项目对热液喷口烟囱中Korarchaeota的分布和丰度进行了综合研究。深海热液喷口的极端环境中栖息着各种各样的微生物群落，它们代表着广泛的代谢能力。这些群落的高度多样性主要是由于从烟囱内壁受热液影响的内部表面到外壁接近环境条件的微生境沿温度、矿物学和地球化学梯度的高度变异性。虽然已经描述了这些栖息地的微生物多样性，但关于烟囱壁上微生物的数量分布和丰度的信息在很大程度上缺乏。为了了解这些群落的功能以及从地幔到微生物、地下到周围深海的潜在联系，需要了解跨越这些梯度的烟囱内微生物种群的分布、丰度和代谢能力。在我们对这些微生物群落的理解中，最大的差距之一在于基本上未被表征的古菌群，即Korarchaeota。本文提出了一个严谨的统计框架，将古岩种型的分布和丰度与热液喷口烟囱的温度和地球化学数据联系起来。这项工作将使用由合作实验室在Juan de Fuca山脊Endeavor部分的硫化物烟囱中植入的新型原位孵育装置收集的数据。孵化装置是钛管内衬衬底（例如黄铁矿），并配备温度传感器和原位流体取样装置，将其放置在硫化物（烟囱）侧面钻的直径5厘米的孔中。这些设备是奋进综合研究中心正在进行的一项研究的一部分。克隆文库将从钻探过程中获得的烟囱岩心中开发出来。这些文库将用于开发和测试引物，以确定现存的古细菌种型。在插入物恢复后，将通过定量PCR对培养的底物进行分析，以枚举古细菌的种型。这些数据将使我们能够将Korarchaeota的分布和丰度与合作实验室生成的地球化学和温度剖面联系起来。本研究的智力价值在于提供了关于火山口生境中Korarchaeota的多样性、分布和丰度的定量数据。该研究还将定义热液喷口烟囱中Korarchaeota的实现生态位，提供新的统计建模工具，用于完善当前的假设，并关注未来对喷口群落中Korarchaeota种型潜在代谢能力的研究。这项研究的广泛影响包括在新的研究领域培养一名新任命的教员和一名博士后研究员。Girguis博士和Cordes博士之间的合作将首次对热液喷口栖息地的Korarchaeota进行量化，并将为Korarchaeota种型的代谢能力形成可处理的假设。Cordes博士将与Ridge2000的SEAS项目合作，开发一个从教室到海洋的实验室，将这项研究与中学生联系起来。

This project describes an integrative study of distribution and abundance of the Korarchaeota in hydrothermal vent chimneys. Diverse microbial communities representing a wide array of metabolic capacities inhabit the extreme environments of deep-sea hydrothermal vents. The high diversity in these communities is largely a result of high microhabitat variability along gradients in temperature, mineralogy, and geochemistry from the inner, hydrothermally influenced surfaces on the inner walls of the chimney to the near ambient conditions of the outer walls. Although the microbial diversity has been described in these habitats, information on the quantitative distribution and abundance of microbes within the chimney walls is largely lacking. In order to understand the function of these communities and the potential links from mantle to microbe and subsurface to surrounding deep-sea, the distribution, abundance, and metabolic capacity of microbial populations within the chimneys that span these gradients are required. One of the largest gaps in our understanding of these microbial communities lies in the largely uncharacterized archaeal group, the Korarchaeota. This proposal describes a rigorous statistical framework for relating the distribution and abundance of korarchaeote phylotypes to temperature and geochemical data from hydrothermal vent chimneys.This work will use data gathered from novel in situ incubation devices implanted in sulfide chimneys on the Endeavor segment of the Juan de Fuca ridge by collaborating laboratories. Incubation devices are titanium tubes lined with substrates (e.g. pyrite) and equipped with temperature sensors and in situ fluid sampling devices, which are placed into 5 cm diameter holes drilled in the sides of sulfides (chimneys). These devices were implanted as part of an ongoing study at the Endeavor Integrated Study Site. Clone libraries will be developed from the chimney cores obtained during drilling. These libraries will be used to develop and test primers for the korarchaeote phylotypes present. After recovery of the inserts, incubated substrates will be analyzed via quantitative PCR to enumerate korarchaeote phylotypes. These data will allow us to relate the distribution and abundance of the Korarchaeota to the geochemical and temperature profiles generated by collaborating laboratories. The intellectual merit of the proposed research lies in the provision of quantitative data on the diversity, distribution and abundance of the Korarchaeota in the vent habitat. This study will also define the realized niche of the Korarchaeota within hydrothermal vent chimneys, providing new statistical modeling tools that will be used to refine current hypotheses and focus future studies of the potential metabolic capacities of korarchaeote phylotypes in vent communities. The broader impacts of this study include the training of a newly appointed faculty member and a post-doctoral researcher in new fields of study. This collaboration between Dr. Girguis and Dr. Cordes will provide the first quantification of the Korarchaeota in the hydrothermal vent habitat and will lead to the formation of tractable hypotheses for the metabolic capacity of korarchaeote phylotypes. Dr. Cordes will work with the SEAS program within Ridge2000 to develop a Classroom to Sea laboratory to relate this research to middle and high school students.