Targeted environmental probing: Linking microorganisms with biogeochemical function at Fe- and Mn-rich, diffuse hydrothermal vents

该项目的主要目的是确定哪些微生物参与了热液喷口系统中的CO2固定和Mn氧化。研究人员将采用生物地球化学、微生物学和分子生物学方法，更全面地了解将金属氧化与碳固定相结合的微生物群落，从而推动玄武岩风化和维持深海生态系统。他们的策略包括：1)以培养为基础的方法，分离出更多具有生态意义的菌株，并确定Mn氧化细菌是否可能在混合或纯培养中将无机碳固定为有机碳；2)不依赖培养的方法，确定环境中负责固定碳的关键化质自养生物；3)肽探针，将Mn氧化物和相关微生物与其他颗粒和微生物物理分离；对氧化锰相关微生物的大分子（DNA和/或脂质）的分析将提供对环境样品中氧化锰生物矿化负责的生物的第一个直接系统发育鉴定。更广泛的影响：从热液区分离自养Mn（II）氧化细菌是该项目的主要目标，将对理解锰循环产生广泛的影响。该博士后候选人在博士学习期间已经有了很好的外展和教育活动记录，并且与高中生的拟议合作对这项工作的广泛影响具有很大的价值。

The primary objective of this project is to determine which microorganisms are involved in CO2 fixation and Mn oxidation in hydrothermal vent systems. The researchers will employ biogeochemical, microbiological, and molecular biological methods to gain a more complete understanding of the microbial communities that are coupling metal oxidation to carbon fixation, thus driving basalt weathering and sustaining ecosystems in the deep-sea. Their strategy includes 1) culture-based methods to isolate more ecologically significant strains and to determine whether Mn-oxidizing bacteria may play a role in fixation of inorganic carbon into organic carbon in mixed or pure cultures, 2) culture-independent methods to identify the key chemolithoautotrophic organisms responsible for carbon fixation in the environment, and 3) peptide probes to physically separate Mn oxides and associated microorganisms from other particles and microbes; analysis of macromolecules (DNA and/or lipids) of the Mn oxide-associated microorganisms will provide the first direct phylogenetic identification of the organisms responsible for Mn oxide biomineralization in environmental samples.Broader Impacts:Isolating autotrophic Mn(II)-oxidizing bacteria from hydrothermal fields, the main objective of this project, will have a broad impact on understanding the manganese cycle. The postdoctoral candidate has already a great track record of outreach and education activities during her Ph.D. studies, and the proposed collaboration with high school students is a great value to the broad impact of this work.