Discovery and Characterization of Uncultivated Bacteria, Archaea and Protista from the San Pedro Channel Time Series

该奖项在洛杉矶和圣卡塔利纳岛南加州大学箭牌海洋科学中心之间的海洋站点建立了一个微生物观测站，以发现和研究以前未描述的微生物。海洋微生物在海洋的生物和化学中发挥着关键作用，因此对从有毒藻类水华的发展到生态系统中的碳循环等各种过程都有很大的影响，从而最终影响到沿海海洋的渔业和其他用途。微小的体型和缺乏易于区分的形态特征，加上在实验室培养微生物的难度和费用，使得直到最近才极难识别这些物种中的大多数。这种情况尤其适用于海洋古生物、细菌以及最小的微藻和原生动物。因此，关于水柱中存在的微生物的种类、它们在时间和空间上的变化以及它们可能正在做什么，缺乏重要的细节。该项目将应用新开发的分子生物学方法，使我们能够根据最小的微生物的遗传特征，直接从田间样本中发现和鉴定它们，而不需要在实验室培养。不同的微生物类型也将使用最先进的荧光探针技术直接从现场样本中进行量化，并将应用同位素-荧光探针技术来调查混合自然群落中优势已识别生物的生理特征。在这个为期4年的项目的大部分时间里，测量将每两周进行一次。南加州大学瑞格利环境研究所将为进入研究地点提供便利，该研究所运营一个海洋时间序列站，每两周采样一次，此外，还将有船只每周两次往返于洛杉矶和南加州大学海洋实验室之间。该项目将充分利用已经为海洋时间序列收集的物理、生物和化学数据。预计这项研究将发现新的微生物物种(基于以前未报道的遗传特征)，指出将这些新发现的微生物带入实验室培养的新方法(基于对其DNA序列的系统发育分析)，从而回答有关地球上最丰富但知之甚少的生物群之一的组成和活动的许多问题。

This award establishes a microbial observatory at an ocean site located midway between Los Angeles and the University of Southern California's Wrigley Marine Science Center on Santa Catalina Island to discover and study previously undescribed microorganisms. Marine microorganisms play crucial roles in the biology and chemistry of the sea and thus have a strong influence on processes ranging from the development of toxic algal blooms to carbon cycling in the ecosystem, and thus ultimately on fisheries and other uses of the coastal ocean. The tiny size and lack of easily distinguishable morphological features, plus the difficulty and expense of cultivating microorganisms in the laboratory, have made it extremely difficult to identify most of these species until very recently. This situation has been particularly true of marine archaea, bacteria, and the smallest microalgae and protozoa. Therefore, important details are lacking regarding the kinds of microorganisms present in the water column, how they vary in time and space, and exactly what they might be doing. This project will apply newly developed molecular biological approaches that will permit us to discover and identify even the smallest microorganisms by their genetic characteristics, directly from field samples and without the need to grow them in laboratory culture. The different microbial types will also be quantified directly from field samples with state-of-the-art fluorescence probe technology, and a combined isotope-fluorescence probe technology will be applied to investigate the physiological characteristics of the dominant identified organisms within their mixed natural communities. Measurements will be taken biweekly for most of the 4-year project. Access to the study site will be facilitated by the USC Wrigley Institute for Environmental Studies which operates an oceanographic time series station with biweekly sampling, and also by boats traversing between LA and USC's marine laboratory twice weekly. The project will take full advantage of the physical, biological, and chemical data already being collected for the ocean time series. It is anticipated that this study will discover new species of microorganisms (based on previously unreported genetic signatures), indicate new approaches for bringing these newly discovered microbes into laboratory culture (based on phylogenetic analyses of their DNA sequences), and thus answer many questions concerning the composition and activities of one of the most abundant yet poorly understood groups of organisms on the face of the planet.