Collaborative Research: Cobalamin and Iron Co-Limitation Of Phytoplankton Species in Terra Nova Bay

合作研究：钴胺素和铁对特拉诺瓦湾浮游植物物种的共同限制

• 批准号: 1643845
• 负责人: Robert Dunbar
• 金额: $ 36.44万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1643845&HistoricalAwards=false
• 关键词: Collaborative; Research; Cobalamin; Iron; Co

Phytoplankton blooms in the coastal waters of the Ross Sea, Antarctica are typically dominated by either diatoms or Phaeocystis Antarctica (a flagellated algae that often can form large colonies in a gelatinous matrix). The project seeks to determine if an association of bacterial populations with Phaeocystis antarctica colonies can directly supply Phaeocystis with Vitamin B12, which can be an important co-limiting micronutrient in the Ross Sea. The supply of an essential vitamin coupled with the ability to grow at lower iron concentrations may put Phaeocystis at a competitive advantage over diatoms. Because Phaeocystis cells can fix more carbon than diatoms and Phaeocystis are not grazed as efficiently as diatoms, the project will help in refining understanding of carbon dynamics in the region as well as the basis of the food web webs. Such understanding also has the potential to help refine predictive ecological models for the region. The project will conduct public outreach activities and will contribute to undergraduate and graduate research. Engagement of underrepresented students will occur during summer student internships. A collaboration with Italian Antarctic researchers, who have been studying the Terra Nova Bay ecosystem since the 1980s, aims to enhance the project and promote international scientific collaborations. The study will test whether a mutualistic symbioses between attached bacteria and Phaeocystis provides colonial cells a mechanism for alleviating chronic Vitamin B12 co-limitation effects thereby conferring them with a competitive advantage over diatom communities. The use of drifters in a time series study will provide the opportunity to track in both space and time a developing algal bloom in Terra Nova Bay and to determine community structure and the physiological nutrient status of microbial populations. A combination of flow cytometry, proteomics, metatranscriptomics, radioisotopic and stable isotopic labeling experiments will determine carbon and nutrient uptake rates and the role of bacteria in mitigating potential vitamin B12 and iron limitation. Membrane inlet and proton transfer reaction mass spectrometry will also be used to estimate net community production and release of volatile organic carbon compounds that are climatically active. Understanding how environmental parameters can influence microbial community dynamics in Antarctic coastal waters will advance an understanding of how changes in ocean stratification and chemistry could impact the biogeochemistry and food web dynamics of Southern Ocean ecosystems.

南极洲沿海水域中的浮游植物盛开通常由硅藻或南极鼠（一种鞭毛的藻类）主导（一种通常可以在胶质基质中形成大殖民地的鞭毛藻）。该项目旨在确定细菌群体与白囊菌群的缔合是否可以直接使用维生素B12供应，这可能是罗斯海中重要的共限制微量营养素。必需维生素的供应以及在较低铁浓度下生长的能力可能使磷酸囊性具有比硅藻的竞争优势。由于小囊细胞比硅藻可以固定更多的碳，而phaeocystis不像硅藻那样有效地放牧，因此该项目将有助于完善对该地区碳动力学以及食品网络网的基础的理解。这种理解也有可能帮助改善该地区的预测生态模型。该项目将进行公共外展活动，并为本科和研究生研究做出贡献。在夏季学生实习期间，将发生代表性不足的学生的参与。自1980年代以来一直在研究Terra Nova Bay生态系统的意大利南极研究人员的合作旨在增强项目并促进国际科学合作。该研究将测试附着的细菌和卵囊之间的互生性共生性是否为殖民细胞提供了一种减轻慢性维生素B12共限定效应的机制，从而使它们具有比硅藻社区的竞争优势。 在时间序列研究中使用漂流者将为在Terra Nova湾的空间和时间上跟踪藻华的发展提供机会，并确定社区结构和微生物种群的生理营养状况。 流式细胞仪，蛋白质组学，元文字，放射性异位素和稳定的同位素标记实验的结合将确定碳和营养摄取率以及细菌在缓解潜在维生素B12和铁限制中的作用。 膜入口和质子转移反应质谱法还将用于估计社区的净生产和挥发性有机碳化合物的释放。了解环境参数如何影响南极沿海水域中的微生物社区动态，将进一步了解海洋分层和化学的变化如何影响南方海洋生态系统的生物地球化学和食物网络动态。

项目成果

Beryllium isotope variations recorded in the Adélie Basin, East Antarctica reflect Holocene changes in ice dynamics, productivity, and scavenging efficiency

南极洲东部阿德利盆地记录的铍同位素变化反映了全新世冰动力学、生产力和清除效率的变化

• DOI: 10.1016/j.qsa.2022.100054
• 发表时间: 2022
• 期刊: Quaternary Science Advances
• 影响因子: 4.5
• 作者: Behrens, Bethany C.;Yokoyama, Yusuke;Miyairi, Yosuke;Sproson, Adam D.;Yamane, Masako;Jimenez-Espejo, Francisco J.;McKay, Robert M.;Johnson, Katelyn M.;Escutia, Carlota;Dunbar, Robert B.
• 通讯作者: Dunbar, Robert B.

Isoscape Models of the Southern Ocean: Predicting Spatial and Temporal Variability in Carbon and Nitrogen Isotope Compositions of Particulate Organic Matter

• DOI: 10.1029/2020gb006901
• 发表时间: 2021-09-01
• 期刊: GLOBAL BIOGEOCHEMICAL CYCLES
• 影响因子: 5.2
• 作者: Glew, Katie St John;Espinasse, Boris;Trueman, Clive N.
• 通讯作者: Trueman, Clive N.

Mid-Holocene Antarctic sea-ice increase driven by marine ice sheet retreat

海洋冰盖退缩导致全新世中期南极海冰增加

• DOI: 10.5194/cp-17-1-2021
• 发表时间: 2021
• 期刊: Climate of the Past
• 影响因子: 4.3
• 作者: Ashley, Kate E.;McKay, Robert;Etourneau, Johan;Jimenez-Espejo, Francisco J.;Condron, Alan;Albot, Anna;Crosta, Xavier;Riesselman, Christina;Seki, Osamu;Massé, Guillaume
• 通讯作者: Massé, Guillaume

Sensitivity of Holocene East Antarctic productivity to subdecadal variability set by sea ice

• DOI: 10.1038/s41561-021-00816-y
• 发表时间: 2021-09
• 期刊: Nature Geoscience
• 影响因子: 18.3
• 作者: Katelyn M. Johnson;R. McKay;J. Etourneau;F. Jiménez-Espejo;Anya Albot;C. Riesselman;N. Bertler;H. Horgan;X. Crosta;J. Bendle;Kate E. Ashley;M. Yamane;Y. Yokoyama;S. Pekar;C. Escutia;R. Dunbar