Investigating the Biological Function of Sterols and Hopanoids in Methylococcus capsulatus

研究荚膜甲基球菌中甾醇和霍烷类化合物的生物学功能

• 批准号: 1418831
• 负责人: Paula Welander
• 金额: $ 12.08万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-02-15 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1418831&HistoricalAwards=false
• 关键词: Investigating; Biological; Function; Sterols; Hopanoids

The majority of life's history had been dominated by microbes whose metabolic inventions have significantly altered the Earth's surface environment and, in turn, impacted the evolution of life on Earth. Yet our ability to study microbial life in the context of the Earth's distant past has remained a difficult challenge primarily because microbes do not readily leave diagnostic morphological fossils. One of the predominant strategies to overcome this challenge has been the use of "molecular fossils." This approach correlates the occurrence of preserved lipids in ancient rocks with their production in modern bacteria. Two sets of lipids that have emerged as powerful geological biomarkers are sterols, produced primarily by eukaryotes, and the sterol-like hopanoids, produced only by bacterial species. In this project, investigators will study the biosynthesis and physiological function of both of these lipids in Methylococcus capsulatus. The ability to produce both sets of lipids is rarely observed in the bacterial domain. Therefore, this organism provides an excellent model system for examining the evolutionary and physiological significance of both hopanoids and sterols with the expectation that these studies will allow for a more informed and robust interpretation of the occurrence of sterols and hopanoids in the rock record. These studies will be carried out through a collaborative effort merging the fields of microbiology and organic geochemistry. The project will train an early career research scientist from an underrepresented minority group and a graduate student in the interdisciplinary field of geobiology.

生命历史的大部分都是由微生物主导的，微生物的代谢发明显着改变了地球表面环境，进而影响了地球上生命的进化。 然而，我们在地球遥远的过去研究微生物生命的能力仍然是一个艰巨的挑战，主要是因为微生物不容易留下诊断性形态化石。克服这一挑战的主要策略之一是使用“分子化石”。这种方法将古代岩石中保存的脂质的出现与现代细菌中的产生联系起来。已成为强大的地质生物标志物的两组脂质是主要由真核生物产生的甾醇和仅由细菌物种产生的类甾醇藿香类化合物。在该项目中，研究人员将研究荚膜甲基球菌中这两种脂质的生物合成和生理功能。在细菌领域很少观察到产生两组脂质的能力。因此，该生物体提供了一个极好的模型系统，用于检查藿类化合物和甾醇的进化和生理意义，期望这些研究将对岩石记录中甾醇和藿类化合物的出现提供更明智和稳健的解释。这些研究将通过微生物学和有机地球化学领域的合作进行。该项目将培训一名来自代表性不足的少数群体的早期职业研究科学家和一名地球生物学跨学科领域的研究生。