Microbes play important roles in the cycling of carbon through our biosphere and thus their activity has profound implications for atmospheric carbon dioxide levels and climate change. The biological pump is a globally significant process in which atmospheric CO2 is transferred to the deep-sea in the form of particulate organic carbon (POC). The bulk of deep-sea metabolism is particle-associated and yet our knowledge of how microbial composition and activity combine to regulate the transformation of POC is limited. Microbial blooms act to stimulate pulses of POC export and thus serve as excellent case studies for examining the roles of free-living and particle-attached microbes in the deep-sea carbon cycle. This study will be conducted in the North Pacific Subtropical Gyre, which has recurring summer blooms, using new molecular techniques that enable the simultaneous examination of taxonomic composition, gene content, and gene expression (metagenomics and metatranscriptomics).
The scientific training objectives of this study are to receive training in metatranscriptomic and metagenomic analysis and gain field experience in oceanographic sampling and deployments. Professional development will be provided by a Professional Development Training program sponsored by the Center for Microbial Oceanography: Research and Education (C-MORE). The broader impacts of the proposed research will be facilitated by C-MORE, which will enable the broad dissemination of scientific findings to the wider community and promote K-12 education through the translation of scientific findings into age-appropriate science kits. Finally, this study will broaden participation of underrepresented ethnic groups by increasing the representation of Hispanic women in biology.
This project supported the postdoctoral training and research in marine microbiology of an early career scientist. During the three-year project, the postdoctoral fellow engaged in a variety of research and outreach activities. Her research focused on understanding the biochemical processes being used by marine microbes to degrade particulate organic compounds (POC) in the ocean. These POCs form a critical part of the marine carbon cycle in that they are an important mediator of CO2 transfer from the atmosphere to the ocean’s interior. As human activity increases the amount of CO2 in the atmosphere, studies which quantify the mechanisms by which CO2 is removed from the atmosphere are increasingly important. Her research revealed the identity and function of microbes that facilitate these processes, which help to improve the accuracy of carbon cycle models that are used to understand the ongoing impacts of climate change. Further, her research revealed previously unknown interrelationships among marine microbes, improving our understanding of marine food webs. She has written a manuscript detailing these findings that is currently in review. The broader impacts of this funding were achieved through the funding of the postdoctoral studies of a female early career scientist of Latino ethnicity. The postdoctoral fellow was able to present her research at a variety of conferences thereby increasing the visibility and impact of underrepresented minorities and women in science. Further, the fellow participated in outreach activities in predominately minority middle schools where she gave biology seminars and encouraged minority students to pursue careers in science.
