REU: Microbial Mediation of Arsenic Redox Cycling in Geothermally-Influenced Surface Waters

REU：受地热影响的地表水中砷氧化还原循环的微生物介导

• 批准号: 9807662
• 负责人: Janet Hering
• 金额: $ 25.5万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9807662&HistoricalAwards=false
• 关键词: REU; Microbial; Mediation; Arsenic; Redox

9807662HeringRapid microbial oxidation of arsenic (As) from the +III to +V oxidation state has been observed in the geothermally-influenced surface waters of Hot Creek Gorge, located in California's Owens Valley. This project will investigate the biochemical mechanism and ecological aspects of this microbial process. Arsenic-oxidizing strain(s) will be isolated from a mixed culture, obtained from Hot Creek, that is currently being maintained in the P.I.'s laboratory and retains the capacity to oxidize As(III). Gene probes (based on 16s-rRNA sequences) will be developed for the mixed culture and used to guide the isolation of pure culture(s) of As(III) oxidizers, to perform genetic characterization and phylogenetic classification of pure strain(s), and to determine the spatial distribution of As(III) oxidizing bacteria at the field site in Hot Creek Gorge. Biochemical studies will be performed with the isolated As(III)-oxidizing strain(s) to determine the kinetics and mechanism of microbial As(III) oxidation. Coupled laboratory and field studies will be conducted to determine whether this process is associated with detoxification or with energy acquisition. If resources allow, a preliminary evaluation will be made of the ecological consequences of the abundant microbial colonization of the surfaces of aquatic macrophytes, which was observed in previous field studies.This proposal was part of the Environmental Geochemistry and Biogeochemistry program. It will be jointly funded by the Division of Ocean Sciences, Division of Chemistry, Division of Earth Sciences, Division of Molecular and Cellular Biosciences, and by the MPS Office of Multidisciplinary Activities.

9807662 Hering在位于加州欧文斯谷的热溪峡谷受地热影响的地表沃茨中，观察到砷（As）从+III氧化态快速氧化为+V氧化态。 本项目将研究这一微生物过程的生化机制和生态学方面。 将从从Hot Creek获得的混合培养物中分离砷氧化菌株，该混合培养物目前保存在P.I.的实验室并保留氧化As（III）的能力。 将为混合培养物开发基因探针（基于16 s-rRNA序列），并用于指导As（III）氧化剂纯培养物的分离，对纯菌株进行遗传表征和系统发育分类，并确定Hot Creek Gorge现场As（III）氧化细菌的空间分布。 将对分离的As（III）氧化菌株进行生化研究，以确定微生物As（III）氧化的动力学和机制。 将进行实验室和实地相结合的研究，以确定这一过程是否与解毒或能量获取有关。 如果资源允许，将对水生植物表面大量微生物定殖的生态后果进行初步评估，这是在以前的实地研究中观察到的。 它将由海洋科学部，化学部，地球科学部，分子和细胞生物科学部以及MPS多学科活动办公室共同资助。