CAREER: Linking novel thermophiles with ecosystem function: Study of a model spring in Nevada

该项目的目标是通过整合化学、微生物学和分子生物学研究，描述在大沸腾泉(内华达州)茁壮成长的不同寻常的微生物，以及它们在这个温泉和大盆地其他温泉中的作用。在地球上的大多数环境中，太阳是维持生命的能量来源。然而，一些环境并不直接依赖于光能，因为它不可用，或者因为物理条件禁止光合作用。例如，在温泉和其他温度持续高于73摄氏度的热栖息地，光合作用停止。在这样的高温下，生物体必须通过转化无机化合物来获得能量，这一过程被称为化学自养。大盆温泉似乎与黄石国家公园中研究得更好的温泉不同，因为它们似乎由不同的化学自养微生物主导。这些特殊的细菌对科学来说是新的。在这项研究中，将测定温泉的相关化学物质，并将其用于计算微生物可利用的能量。据预测，产生最多能量的反应将是春季微生物最重要的反应。其次，这些预测将通过测量泉水中的微生物活动来直接检验，并通过测量沉积物岩心深度的化学变化来间接检验。微生物介导的化学反应的证据及其在春季沉积物中的位置将在化学变化中明显。第三，通过将基因组DNA测序方法与稳定同位素化学相结合，将预测和测量的活性暂定为微生物物种。第四，这些信息将被用来推动实验室培养重要微生物的尝试，以便对它们进行更详细的研究。总而言之，这个项目将使我们能够更好地了解温泉生命的基础，并扩大我们对地球上生命多样性的了解。除了培训本科生、研究生和博士后研究人员外，这项研究还将与一个夏季实地课程协调进行，该课程由联合国志愿人员组织的学生与金字塔湖派尤特部落的美洲原住民高中生和教师一起工作。学生和教师将参加现场和实验室实验，以确定大盆泉在年际时间尺度上的稳定性，包括测量总体化学和伴随而来的沉积物微生物群落的检查。此外，课程将包括客座讲座和由客座科学家、地热工程师、派尤特长老和人类学家领导的实地考察。预计该课程将激发美洲原住民对其自然历史遗产的兴趣，并有助于其管理。温泉是派尤特重要的文化和自然资源，但它们也是地热能源的潜在收入来源。此外，预计派尤特部落的成员和联合国志愿人员组织的学生将通过共同努力了解该地区温泉的科学和文化重要性而受益。

The goal of this project is to characterize the unusual microorganisms that thrive in Great Boiling Spring (Nevada), and their role in this and other hot springs in the Great Basin by integrating chemical, microbiological and molecular biological studies. In most environments on Earth, the sun is the source of energy that sustains life. Some environments, however, are not directly dependent on light energy because it is unavailable or because physical conditions prohibit photosynthesis. For example, in hot springs and other thermal habitats where temperatures are consistently above 73 degrees centigrade, photosynthesis stops. At such high temperatures, organisms must gain energy by transforming inorganic compounds, a process called chemolithoautotrophy. Great Basin hot springs appear to be different from better-studied springs in Yellowstone National Park in that they seem to be dominated by different chemolithoautotrophic microbes. These particular bacteria are new to science. In this study, the relevant chemistry of the hot springs will be determined and used to calculate the energy available to microorganisms. It is predicted that the reactions that yield the most energy will be most important to the microorganisms in the spring. Second, these predictions will be tested directly by measuring microbial activities in the spring and indirectly by measuring chemical changes with depth in sediment cores. Evidence of microbe-mediated chemical reactions and their locations in the spring sediment will be evident in changes in chemistry. Third, the activities that were predicted and measured will be tentatively assigned to microbial species by combining genomic DNA sequencing methods with stable isotope chemistry. Fourth, the information will be used to drive attempts to cultivate important microorganisms in the laboratory so they can be studied in more detail. In summary, this project will allow us to better understand the foundations of life in hot springs, and expand our knowledge of the diversity of life on Earth.In addition to training undergraduate, graduate and postdoctoral researchers, this study will be conducted in coordination with a summer field course involving UNLV students working together with Native American high school students and teachers from the Pyramid Lake Paiute tribe. Students and teachers will participate in field and lab experiments designed to determine how stable Great Basin springs are on an inter-annual timescale including measurement of bulk chemistry and concomitant examination of the sediment microbial community. In addition, classes will include guest lectures and field trips led by guest scientists, geothermal engineers, Paiute elders, and anthropologists. It is anticipated that the course will stimulate Native Americans' interest in, and assist in management of their natural history heritage. Hot springs are important cultural and natural resources for Paiutes but they also represent potential sources of revenue from geothermal energy. Furthermore, it is expected that members of the Paiute tribe and UNLV students will each benefit by working together to understand the scientific and cultural importance of the region's hot springs.