Autonomous Systems for the Collection, in situ Preservation and Return of Microbial Samples from Aquatic Ecosystems

随着研究界从水生微生物的描述性研究过渡到系统级调查，例如，社区对不断变化的地球化学条件，有毒物质泄漏，海洋酸化，扩大氧气最低区，藻类水华动态和食物网动态的反应，研究人员必须拥有满足这些新挑战的仪器。 对不稳定的有机分子如信使RNA、蛋白质和代谢物的研究现在通常用于评估微生物社群活动。用于机器人时间序列或自适应用户控制采样的仪器必须能够将样品采集到过滤器的表面上，并将收集的细胞化学保存在它们所处的环境中（原位），以最大限度地减少所得数据中的伪影。 拟议的技术取样平台的制造和测试将以灵活、多用途水柱取样的形式为研究增加急需的基础设施，这将加强合作研究，并将使更全面和准确的研究微生物群落活动成为可能。 每一项发展努力都将为高中到研究生提供培训机会。 研究结果将提供给海洋研究科学委员会（SCOR）工作组关于海洋微生物学研究拟议实践标准的白色文件，以及伍兹霍尔海洋研究所和Edgcomb实验室网站。 主要研究人员将制作一个免费提供的电子讲座，提交给湖沼学和海洋学电子讲座（www.aslo.org/lectures），介绍这些平台所代表的进展、使用的理由以及预期的商业可用性。 每个平台的功能都是微生物生态学领域所独有的，目的是制造和现场测试两个互补的采样平台，共享我们实验室最近的新技术发展。 这两个平台的能力将使这些进展能够应用于广泛的采样目标，其成功的示范将使人们有可能将这些新技术应用于商业仪器。 一个平台，螺旋旋转阀微型微生物采样器（HRV-MMS）将允许收集至少200个样本（最多4倍，现在可能与现有技术的数量）的足迹内的一个紧凑的仪器，可以很容易地实现在自主水下航行器，遥控潜水器，深潜器，液压铸造，或基于系泊的采样平台。 该平台的大部分工程设计工作已经完成。 第二个拟议的发展涉及微生物取样-潜水培养装置（MS-SID）平台的进步，该平台可以通过水力钢丝部署在固定系泊装置上，或释放在全球定位系统跟踪的水面漂浮系统上，以收集多达48个样本（用户定义的体积取决于过滤器孔隙率和目标过滤时间），每个由同时收集的最多6个重复样品组成（总共288个样品）和/或进行原位培养式微生物代谢率测量。 将在两个平台上实施的新螺旋旋转阀设计在采样流速和显著降低的流阻方面比现有阀技术具有显著优势。

As the research community transitions away from descriptive studies of aquatic microbes to system-level investigations of, for example, community responses to changing geochemical conditions, toxic spills, ocean acidification, expanding Oxygen Minimum Zones, algal bloom dynamics and food web dynamics, it is essential that researchers have instrumentation that meets these new challenges. Studies of labile organic molecules such as messenger RNA, proteins, and metabolites are now routinely used to assess microbial community activities. Instrumentation for robotic time-series or adaptive user-controlled sampling must be capable of acquisition of samples onto the surface of a filter and chemically preserving collected cells at the site in the environment they reside (in situ) to minimize introduction of artifacts in the resulting data. Proposed fabrication and testing of technical sampling platforms will add much needed infrastructure for research in the form of flexible, multiple-application water column sampling that will enhance collaborative research and will make possible more comprehensive and accurate studies microbial community activity. Each development effort will provide training opportunities for high school through graduate students. Results will be contributed to a high-profile Scientific Committee on Oceanic Research (SCOR) Working Group White Paper on proposed standards of practice for studies of marine microbiology, and on Woods Hole Oceanographic Institution and Edgcomb laboratory websites. The principal investigators will produce a freely available E-lecture submitted to Limnology and Oceanography E-Lectures (www.aslo.org/lectures) on the advances represented in these platforms, rationale for their use, and expected commercial availability. The capabilities of each platform will be unique to the field of microbial ecology.The objective will be to fabricate and field test two complementary sampling platforms that share recent new technology developments in our laboratories. The capabilities of the two platforms will enable application of these advances for a wide range of sampling objectives, and demonstration of their successes will make it possible to implement these new technologies into commercially-available instrumentation. One platform, the Helical Rotary Valve-Miniature Microbial Sampler (HRV-MMS) will permit collection of at least 200 samples (up to 4-times the numbers now possible with existing technology) within the footprint of a compact instrument that can be quite readily implemented in Autonomous Underwater Vehicles, Remote Operated Vehicles, Deep Submergence Vehicles, hydrocast, or mooring-based sampling platforms. Most of the engineering design work for this platform has been completed. The second proposed development involves an advancement of the Microbial Sampling-Submersible Incubation Device (MS-SID) platform, which can be deployed by hydrowire, on fixed moorings, or released on Global Positioning System-tracked surface float systems to collect up to 48 samples (user-defined volumes dependent on filter porosity and targeted filtration times), each consisting of up to 6 replicates collected simultaneously (total 288 samples) and/or conduct in situ incubation-style microbial metabolic rate measurements. The new helical rotary valve design that will be implemented on both platforms has significant advantages over existing valve technologies in terms of sampling flow rates and dramatically lower flow resistances.