報告題目： Why are the Ammonia-oxidizing Archaea so successful globally?
报告时间： 11 月 3 日（周四） 下午 1:30
报告地点： 生态科研楼 601 会议室
報告人：David Stahl 院士（美國華盛頓大學教授、美國工程院院士）
個人簡介: David Stahl completed graduate studies in microbial phylogeny and evolution with Carl Woese at the University of Illinois. Subsequent work with Norman Pace, then at the National Jewish Hospital in Colorado, involved early applications of 16S rRNA-based sequence analysis to the study of natural microbial communities. Stahl held appointments at the University of Illinois and Northwestern University before returning in 2000 to his alma mater, the University of Washington, Seattle, as professor in the Departments of Civil and Environmental Engineering and Microbiology. He is known for his work in microbial evolution, ecology, and systematics – receiving the 1999 Bergey Award and the 2006 Procter & Gamble Award in Applied and Environmental Microbiology. He is fellow in the American Academy of Microbiology and a member of the US National Academy of Engineering. His main research interests concern the biogeochemistry of nitrogen and sulfur, and the complex communities that sustain the associated nutrient cycles. His laboratory was first to culture ammonia- oxidizing archaea, a group of mesophilic and thermophilic Archaea now believed to be the main mediator of this key process in the nitrogen cycle. He teaches, and has taught, multiple courses in environmental microbiology, was one of the co-founding editors for the journal Environmental Microbiology, and has served on many advisory committees.
報告摘要: Ammonia-oxidizing archaea (AOA) are generally thought to control ammonia oxidation in most terrestrial, marine, and geothermal habitats. Thus, their discovery was cause to reassess the nitrogen cycle and associated food webs. In particular, the unusually high affinity for ammonia of marine and terrestrial AOA suggests this group may control the oxidation state of nitrogen available to associated microbiota and macrobiota, altering current understanding of trophic interactions in oceanic and soil systems. Comparative genomics and biochemical studies have revealed a novel (primarily copper-based) pathway for ammonia oxidation and the most energy efficient aerobic pathway for carbon fixation yet described. Combined physiological, biochemical, and environmental analyses also implicate the AOA as major contributors to the atmospherically active gases methane and nitrogen oxides. This presentation will now examine more recent findings of their biochemistry and the environmental variables structuring their distribution, diversity, and activities in natural systems.