Collaborative Research: MIP: Pressure Influences on Microbial Life in the Puerto Rico Trench

压力是影响微生物生命演化和分布的物理参数。远离地球？在地球表面，深海海沟代表了生物圈压力的上边界。在这里，科学家们可以研究最极端形式的高压适应。目前还没有研究描述海沟中微生物生命的多样性。为了做到这一点，加州大学圣地亚哥分校的Doug Bartlett和波多黎各-马亚圭斯大学的Wilford Schmidt将使用一种无系绳、自由落体、压力硬化的设备，在大西洋最深的海沟——波多黎各海沟（PRT）中取样细菌和古细菌，深度为8.4公里（5.2英里）。他们将描绘这些原核生物生活的环境（压力、温度、盐度和流速）。他们还将对海沟海水进行化学分析，进行微生物细胞总数和特定微生物群的探针计数，进行DNA提取，分离和培养深层微生物。最后两个目标是项目的核心。他们将利用DNA通过指示基因和群落指纹技术来表征海沟微生物群落。培养这些高压微生物（称为“嗜压菌”）是困难的，因为培养容器处于非常高的压力下，样品难以操作。巴特利特实验室有培养嗜热菌的专业知识所以我们将努力分离PRT中观察到的一些主要微生物群的纯培养物，包括班上的同学？Alphaproteobacteria吗?，黄杆菌目，植物菌目，和海洋I群绿古菌亚纲。他们还将描述特定分离株的生理和分类特征。从长远来看，这些研究人员对研究减压或加压对深沟或地表水微生物组合的影响很感兴趣，因为他们对了解嗜压生物在高压下生存和生长的独特能力很感兴趣。巴特利特和施密特将为波多黎各和南加州的大学预科生和大学生制定推广计划，向他们传授这项研究。他们的努力将包括开设海洋微生物实验课。他们还将为伯奇水族馆的深海展览创造他们研究的亮点。

Pressure is a physical parameter which influences the evolution and distribution of microbial life. Far from Earth?s surface, deep ocean trenches represent the upper boundaries of pressure in the biosphere. This is where scientists can study high pressure adaptations in their most extreme forms. No studies have yet characterized the diversity of microbial life in trenches. In order to do this, Doug Bartlett from UC San Diego and Wilford Schmidt from Univ. Puerto Rico-Mayaguez, will be using an untethered, free-falling, pressured-hardened device to sample bacterial and archaeal life in the deepest trench in the Atlantic Ocean, the Puerto Rico Trench (PRT), at a depth of 8.4 km (5.2 mi). They will profile the ambient environment in which these prokaryotes live (pressure, temperature, salinity, and current velocity). They will also chemically analyze the trench seawater and carry out total microbial cell counts and probe-based counts of particular microbial groups, perform DNA extractions and isolate and culture deep-dwelling microorganisms. It is these last two goals that are at the heart of the project. They will use the DNA to characterize the trench microbial community via indicator genes and community fingerprint techniques. Cultivation of these high pressuring loving microbes (called ?piezophiles?) is difficult since the culture vessels are under very high pressure and the samples are difficult to manipulate. The Bartlett laboratory has the expertise to culture piezophiles and so a major effort will be made to isolate pure cultures of some of the major microbial groups observed in the PRT, including members of the class ?Alphaproteobacteria?, order Flavobacteriales, order Planctomycetales, and subclass marine group I Crenarchaeota. They will also characterize the physiology and taxonomy of particular isolates. In the long term, these investigators are interested in studying the effect of decompression or pressurization on deep-trench or surface-water microbial assemblages because they are interested in understanding the unique abilities of piezophiles to survive and grow under very high pressures. Bartlett and Schmidt will develop outreach programs for pre-college and university students, in Puerto Rico and in southern California, to teach them about this research. Their efforts will include the development of a marine microbiology laboratory class. They will also create highlights from their research for the Birch Aquarium's Deep Ocean Exhibit.