LEXEN: Growth Media for Hyperthermophiles: Geochemical Constraints on Realistic Carbon and Energy Sources in Shallow Marine Hydrothermal Systems

9714288修正项目摘要自1980年以来，对几十种极端嗜热微生物进行了分离和鉴定，这在很大程度上是目前人们对地球极端环境中的生命以及太阳系中其他行星体的生命感兴趣的主要原因。大多数已知的嗜热菌是从深海热液喷口或陆地温泉采集的岩石和水样中培养出来的。尽管从这组相对稀少的生物体中已经了解了许多关于微生物生理学、系统发育多样性和新的代谢途径的知识，但地球和其他地方的真正极端的遗传多样性和代谢策略是不可能先验预测的。被广泛接受的概念强调了这一概念，即目前已知的现有微生物物种不到0.1%。通过应用创新的方法分离和培养新的极端微生物物种，可以扩大有关微生物物种在极端环境中茁壮成长的知识。像所有活着的有机体一样，嗜热性极强的生物与它们的宿主环境密切相关。因此，对热液环境的地球化学的详细了解可能会对生命的基本底物施加限制。为了实现这一总体目标，该项目将结合热力学计算来确定潜在的能源来源，并对热液流体进行详细的化学分析，以设计新的介质来生长各种超嗜热菌。意大利埃利安群岛的温泉，包括伏尔卡诺上的温泉，交通便利，化学成分多样，是进行这项高度跨学科研究的理想采样点。

9714288 Amend PROJECT SUMMARY The isolation and characterization since 1980 of several dozen species of hyperthermophilic microorganisms are largely responsible for the tremendous current interest in life in extreme environments on Earth as well as on other planetary bodies in our solar system. Most known hyperthermophiles were cultured from rock and water samples collected at deep submarine hydrothermal vents or terrestrial hot springs. Although much has been learned about microbial physiologies, phylogenetic diversity, and novel metabolic pathways from this relatively sparse set of organisms, the true extremes of genetic diversity and metabolic strategies on Earth and elsewhere are impossible to predict a priori. This concept is underscored by the widely accepted notion that less than 0.1 percent of all extant microbial species are currently known. Knowledge of microbial species thriving in extreme environments can be expanded through the application of innovative methods to isolate and culture novel species of extremophiles. Like all living organisms, hyperthermophiles are intimately associated with their host environment. Therefore, a detailed understanding of the geochemistry of hydrothermal environments is likely to place constraints on essential substrates for life. To reach this overall goal, this project will combine thermodynamic calculations to determine potential energy sources with detailed chemical analyses of hydrothermal fluids to design new media for growing a wide variety of hyperthermophiles. The readily accessible and chemically diverse hot springs in the Aeolian Islands, Italy, including those on Vulcano, are ideal sampling sites for this highly interdisciplinary study.