Collaborative Research: Role of Meso- and Bathypelagic prokaryotic Organisms in the Marine Water Column: Insights from Compound-Specific Radiocarbon Analysis

尽管在泛光带之下的中深海和深海区域包含了几乎所有的海洋体积，但人们对该区域的生物地球化学过程知之甚少。出于这个原因，斯克里普斯海洋研究所的一名PI将与哈佛大学的一名PI合作，确定在中远洋和深海中，哪些碳源可以为原核生物的生产提供燃料。具体而言，pi希望解决以下两个问题：(1)新鲜生产的有机物是深海异养原核生物可获得的主要溶解有机碳（DOC）池，还是“旧”DOC也是生物可利用的？浮游古细菌对无机碳的化学自养固定是否是深海碳循环的重要组成部分？为了解决这些问题，PIs计划测量碳源库的放射性碳（14C）浓度以及由此产生的表层、中表层（500-600米）和深海（900米）的prolaryotic（细菌和古细菌）生物量。此外，荧光原位杂交（FISH）和变性梯度凝胶电泳（DGGE）遗传多样性分析将提供生物群落的互补图。最后，为了获得本研究所需的大量生物质衍生碳，PIs计划开发一种原位、电池供电的潜水泵，在研究的第一年，每次部署可泵送20,000升海水。

ABSTRACTOCE-0242160OCE-0241363Even though the meso- and bathypelagic regions beneath the euphotic zone contain nearly all of the oceans volume, little is known about the biogeochemical processes that function in this region. For this reason, a PI from Scripps Institute of Oceanography will collaborate with a PI from Harvard University to determine which carbon sources fuel prokaryotic production in the meso- and bathypelagic ocean. Specifically, the PIs wish to address the following two questions: (1) Is freshly-produced organic matter the primary dissolved organic carbon (DOC) pool that is accessible to deep ocean heterotrophic prokaryotes or is "old" DOC also bioavailable?; and (2) Is chemoautotrophic fixation of inorganic carbon by planktonic archaea an important component of the deep ocean carbon cycle? To address these questions, the PIs plan to measure the radiocarbon (14C) concentration of the carbon source pools and the resulting prolaryotic (bacterial and archaeal) biomass at the surface, meso (500-600 m) and bathypelagic (900 m) depths. In addition, fluorescent in-situ hybridization (FISH) and genetic diversity analysis by denaturing gradient gel electrophorsis (DGGE) will provide a complementary picture of the biological community. Lastly, to obtain the large quantities of biomass-derived carbon needed for this study, the PIs plan to develop an in-situ, battery powered, submersible pump capable of pumping 20,000L of seawater per deployment during the first year of the study.