Cross-Site: Microbial Loop Dynamics and Regulation of Bacterial Physiology in Subtropical and Polar Marine Habitats

跨站点：亚热带和极地海洋栖息地的微生物循环动力学和细菌生理学调节

• 批准号: 9526986
• 负责人: David Karl
• 金额: $ 15.81万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-01-01 至 1998-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9526986&HistoricalAwards=false
• 关键词: Cross; Site; Microbial; Loop; Dynamics

The microbial loop has been shown to play an important role in marine and freshwater plankton ecosystems in all climatic zones. Earlier research in two contrasting habitats: an Antarctic coastal/ shelf/oceanic ecosystem and a subtropical oceanic ecosystem, have shown significant differences in the ecological role of the microbial loop and the physiology of bacterioplankton. These two habitats are isolated from input of terrestrially derived organic matter and so provide excellent opportunities to study bacterial metabolism of autochthonous organic matter of phytoplankton origin. Strong contrasts in plankton community parameters make these two sites ideal for this comparison. This study will be embedded within on-going programs at each of these two sites (US-JGOFS Hawaii Ocean Time-series in the North Pacific and Palmer LTER in Antarctica) that provide both logistical support and supporting data on a wide range of hydrographic, chemical and biological parameters, with extensive documentation of spatial and temporal variation. Preliminary field results show that bacterial communities in th ese two areas are physiologically distinct, that bacterial physiology is regulated by the structure of the microbial community and particularly by grazer recycling of nitrogen, that organic compounds rare in seawater, especially histidine, play a large role in regulation of bacterial ectoenzyme expression, and that photolysis of dissolved organic matter by solar ultraviolet radiation also plays a role in regulation of bacterial ectoenzymes. More thorough investigation of these phenomena in ecologically distinct microbial communities will facilitate understanding of the complex interactions between bacterioplankton and the rest of the microbial community.

已经显示，微生物环在所有气候区域中都在海洋和淡水浮游生物生态系统中起重要作用。在两个对比栖息地的早期研究：南极/货架/海洋生态系统和亚热带海洋生态系统的研究表明，微生物循环的生态作用和细菌浮游生物的生理学显着差异。这两个栖息地是从地面衍生的有机物的投入中分离出来的，因此提供了研究浮游植物自然有机物的细菌代谢的绝佳机会。浮游生物社区参数的强烈对比使这两个站点是此比较的理想选择。这项研究将嵌入到这两个地点的每个站点（北太平洋的夏威夷夏威夷海洋时间序列和南极洲的Palmer lter）中的每个持续计划中，这些景点既可以提供后勤支持，又提供有关水文范围的数据的支持数据化学和生物学参数，并具有广泛的空间和时间变化文献。初步领域的结果表明，这两个领域的细菌群落在生理上是不同的，细菌生理学受微生物群落的结构，尤其是氮的结构，尤其是氮的再生，这种有机化合物在海水中罕见，尤其是组氨酸的作用，起着很大的作用。在调节细菌外酶表达中，太阳能紫外线辐射对溶解有机物的光解也在调节细菌外胚酶的调节中起作用。对生态不同的微生物群落中这些现象的更彻底的研究将有助于理解细菌团体与其他微生物群落之间的复杂相互作用。