Carbon Fixation and Nitrate Respiration in the Hydrothermal Vent Tubeworm Riftia Pachyptila

费尔贝克9314525深海热液喷口的自由生活和共生细菌利用地热过程形成的硫化物作为化学自养过程的能源。为了描述喷口群落中碳的流动，需要了解无机碳(CO2)最初是如何结合到有机化合物中的，以及使用哪些能源。同样重要的是要了解这些碳最终从喷口细菌转移到群落的其他部分的机制，特别是热液喷口管虫Riftia pachyptila。因此，本项目将集中于三个研究目标：(1)量化二氧化碳在血液中作为有机分子的运输；(2)追踪琥珀酸的命运，琥珀酸是从细菌转移到宿主的分子，以及血液中携带最大比例外部二氧化碳的有机酸；以及(3)确定两种可供选择的电子受体对硫化物氧化的相对重要性，例如，氧和硝酸盐呼吸。这项研究的结果将描绘参与喷口群落合成有机质的重要生化途径和机制，这对于理解深海热液喷口的化学自养过程是至关重要的。***

Felbeck 9314525 Free-living and symbiotic bacteria at deep-sea hydrothermal vents use the sulfide formed by geothermal processes as an energy source for chemoautotrophic processes. In order to describe the flow of carbon in a vent community, information is required on how inorganic carbon (CO2) is originally incorporated into organic compounds, and with which energy sources. It's also important to understand the mechanism by which this carbon is eventually transferred from vent bacteria to rest of the community, in particular the hydrothermal-vent tubeworm Riftia pachyptila. Therefore, this project will focus on three research objectives: (1) quantify the transport of CO2 as organic molecules in the blood R. pachyptila; (2) trace the fate of succinate, the molecule transferred from bacteria to their hosts as well as the organic acid carrying the largest proportion of external CO2 in the blood; and (3) determine the relative importance of two alternative electron acceptors for sulfide oxidation, e.g., oxygen and nitrate respiration in R. pachyptila. The results of this research will delineate the important biochemical pathways and mechanisms involved in the synthesis of organic matter by vent communities, which is central to understanding chemoautotrophic processes at deep-sea hydrothermal vents. ***