Collaborative Research: Evolution Of Environments Within Black Smoker Chimney Walls: Microbial Colonization As Functions Of Temperature, Chemistry, And Time

研究人员将调查在瓜伊马斯盆地热液系统中活跃形成的烟囱沉积物中微生物与其地球化学环境的相互作用。本研究的具体目标有两个方面。 首先，他们将在几分钟到几个月的时间尺度上追踪新形成的烟囱壁内的热/化学/物理环境的演变，并确定微生物在这个时间/化学/热/空间框架内的分布。第二、他们将评估地下地球化学过程，这些过程负责将有机和无机代谢能源和营养物质从深层反应区输送到近海底环境。这些目标将通过与Debra Stakes博士（MBARI），兰迪科斯基（美国地质勘探局），和杰夫小麦（阿拉斯加大学费尔班克斯MBARI校园），使用MBARI RN西部传单和蒂伯龙。新形成的烟囱的壁内的温度将使用热电偶阵列进行监测，在烟囱生长过程中被包围。随后将回收新的烟囱，并将每个热电偶附近的固体材料用于富集培养，分子系统发育方法和16 S rRNA特异性探针的荧光原位杂交，同时将对相同材料的碎片进行矿物学，化学和同位素组成的充分表征。将使用一个全面的分析计划来分析从深层地下反应区向海底输送营养物质和化学能的排气流体，该计划涉及定量测定含水有机物、无机物和气态物质的丰度。流体和固体的成分数据将用于约束热力学和扩散-平流模型，这些模型允许估计烟囱壁内的流体成分和温度，这些信息将有助于计算可用于代谢活动的化学能的数量和来源。烟囱矿物的矿物学、化学和同位素分析将提供关于烟囱演化时存在的条件的关键信息，这些信息可以与热电偶记录的热历史进行比较，并与模型计算结果进行了比较，结果表明，P-T-已知的X条件将解决有关微生物如何在这些极端环境中生长的重要问题，以及微生物多样性和演替的地球化学限制。研究人员将使用的方法都已成功应用于其他喷口部位。这项研究的独特之处在于将这些技术和跨学科专业知识相结合，以评估喷口环境中的地球化学过程。

The researchers will investigate the interaction of microorganisms with their geochernical environment in chimney deposits that are actively forming in the Guaymas Basin hydrothermal system. The specific objectives of this study are twofold. First, they will trace the evolution of the thermal/chemical/physical environment within newly formed chimney walls over time-scales of minutes to months and determine the distribution of microorganisms within this temporal/chemical/thermal/spatiaI framework. Second, they will assess subsurface geochemical processes responsible for the delivery of organic and inorganic metabolic energy sources and nutrients from deep-seated reaction zones to near seafloor environments.These goals will be attained by identifying microbial populations that inhabit well-constrained temperature and compositional domains within the walls of newly formed and existing chimneys through a collaborative and interdisciplinary study with Drs. Debra Stakes (MBARI), Randy Koski (USGS), and Geoff Wheat (University of Alaska Fairbanks-MBARI campus), using the MBARI RN Western Flyer and ROV Tiburon. Temperature within the walls of newly formed chimneys will be monitored using thermocouple arrays that are enveloped during chimney growth. The new chimneys will subsequently be recovered and the solid material in the immediate vicinity of each thermocouple used for enrichment cultures, molecular phylogenetic approaches, and fluorescent in situ hybridization with 16S rRNA-specific probes, while splits of the same material will be fully characterized with respect to their mineralogic, chemical, and isotopic composition. Vent fluids delivering nutrients and chemical energy from deep-seated subsurface reaction zones to the seafloor will be analyzed using a comprehensive analytical plan that involves quantitative determination of the abundance of aqueous organic, inorganic, and gaseous species. Compositional data for fluids and solids will be used to constrain thermodynamic and diffusive-advective models that allow estimation of fluid composition and temperature within chimney walls, information that will facilitate calculation of the amounts and sources of chemical energy available for metabolic activity. Mineralogical, chemical, and isotopic analyses of chimney minerals will provide key information on conditions present as the chimneys have evolved that can be compared to the thermal history as recorded by the thermocouples, and to the results of model calculations.The resultant understanding of the time dependent colonization of chimney environments in which the P-T-X conditions are known will address important questions about how microorganisms grow in these extreme environments, and what the geochemical constraints are on microbial diversity and succession. The methods the investigators will use have all been applied successfully at other vent sites. What makes this research unique is the combination of these technologies and interdisciplinary expertise to assess biogeochemical processes within vent environments.