MIP: Abundance, Diversity, and Activity of Anaerobic Propane- and Butane-Oxidizing Microorganisms at a Hydrothermal Hydrocarbon Seep

在许多海洋沉积物中，碳氢化合物可以达到高浓度，是微生物群落的潜在重要底物。大量碳氢化合物自然进入生物圈的最壮观的地方之一是位于加利福尼亚湾瓜伊马斯盆地的深海热液喷口。将从瓜伊马斯盆地沉积物覆盖的热液系统中收集沉积物岩心和喷口流体，用于微生物学和地球化学研究。荧光原位杂交（FISH）将与地球化学分析相结合，以评估以前富集和分离的生物的丰度和分布。此外，稳定同位素探测（SIP）将用于原位识别进行厌氧丙烷和丁烷氧化的微生物，并在各种条件下富集和分离利用这些碳氢化合物的新生物。本研究将确定天然碳氢化合物渗漏的原位地球化学条件与降解气态碳氢化合物的厌氧微生物的丰度和分布之间的关系。碳氢化合物的厌氧生物降解极大地扩展了可能支持生命的地质环境的范围，并对我们理解地球上调节生命和碳循环的因素具有深远的意义。这项研究的结果与石油工业直接相关，越来越多的研究表明丙烷和丁烷在地下油藏中优先降解。因此，更好地理解微生物催化这一过程的生态和环境重要性，对于深化我们对海洋沉积物、陆地地下和经济上可行的石油聚集的生物地球化学过程的认识具有重要意义。该项目的更广泛影响包括在网上传播数据，促进思想交流，促进教育和外联活动。本科生和研究生将学习微生物生态学、地球生物学和地球化学的现代方法。为了进一步了解生物圈和地圈之间的相互作用，教育下一代科学家使他们能够广泛交谈和进行跨学科研究变得越来越重要。

In many ocean sediments, hydrocarbons can reach high concentrations and are potentially important substrates for microbial communities. One of the most spectacular places where large quantities of hydrocarbons are naturally introduced into the biosphere is the deep-sea hydrothermal vent site in Guaymas Basin, in the Gulf of California. Sediment cores and vent fluids will be collected for microbiological and geochemical studies from the sediment-covered hydrothermal system at Guaymas Basin. Fluorescence in situ hybridization (FISH) in combination with geochemical analyses will be performed to assess the abundance and distribution of previously enriched and isolated organisms. Furthermore, stable isotope probing (SIP) will be utilized to identify microorganisms carrying out anaerobic propane and butane oxidation in situ, and novel organisms utilizing these hydrocarbons will be enriched and isolated under a wide range of conditions. This study will determine the relationship between in situ geochemical conditions at naturally occurring hydrocarbon seeps and the abundance and distribution of anaerobic microorganisms that degrade gaseous hydrocarbons. Anaerobic biodegradation of hydrocarbons greatly expands the range of geologic environments that may support life and has profound implications for our understanding of factors that regulate life and carbon cycling on earth.Results of this investigation have direct relevance to the petroleum industry where a growing number of studies indicate the preferential degradation of propane and butane in subsurface petroleum reservoirs. Thus, a better understanding of the ecology and environmental importance of microorganisms catalyzing this process has implications for deepening our insights of biogeochemical processes in marine sediments, the terrestrial subsurface, and economically viable petroleum accumulations. Broader impacts of this project include the web-based dissemination of data, facilitating the exchange of ideas, and promoting educational and outreach activities. Undergraduate and graduate students will be trained in modern methods of microbial ecology, geobiology, and geochemistry. To further an understanding of the interactions between the biosphere and geosphere, it is becoming increasingly important to educate the future generation of scientists in a way that they are able to converse widely and conduct interdisciplinary research.