LExEn: Diversity of Electron Donors and Electron Acceptors Supporting the Growth of Hyperthermophilic Microorganisms.

LExEn：电子供体和电子受体的多样性支持超嗜热微生物的生长。

• 批准号: 0085365
• 负责人: Derek Lovley
• 金额: $ 47.5万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-10-01 至 2003-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0085365&HistoricalAwards=false
• 关键词: LExEn; Diversity; Electron; Donors; Acceptors

0085365LovelyMicroorganisms are thought to have an important impact on the geochemistry of hot (80-110 degrees C), oxygen-depleted environments such as those found deep below the Earth's surface, at the bottom of the ocean, and around terrestrial hot springs. The goal of this research is to evaluate the metabolic diversity of anaerobic hyperthermophilic microorganisms in order to learn more about the biogeochemical processes that are possible in hot microbial ecosystems. It is hypothesized that there is wide diversity of microorganisms that are capable of living in hot environments by oxidizing organic compounds such as: acetate and other short-chain fatty acids, long-chain fatty acids, amino acids, aromatic compounds, and a variety of hydrocarbons. Electron acceptors for the oxidation of these organic compounds are predicted to include Fe(III), sulfate, S (zero), or nitrate. It is proposed that in the absence of these electron acceptors that these organic compounds can be microbially converted to methane. Novel strategies will be employed in an attempt to recover autotrophic, hydrogen-oxidizing, Fe(III)-reducing hyperthermophiles because it is hypothesized that some organisms with this form of respiration will phylogenetically be among the most deeply branching microorganisms still existing on Earth. In order to evaluate the possibility that Fe(III) reducers may be active in hot, acidic environments, an attempt will be made to recover acidophilic hyperthermophiles that can reduce the soluble Fe(III) found at low pH. The possibility that Fe(III)-reducing hyperthermophiles produce isotopically unique Fe(II) minerals will be evaluated by examining the oxygen and iron isotopes in these minerals. It is expected that these studies will provide further insight into the biology and geology of hot microbial ecosystems on Earth as well as the microbial ecosystems that may exist in the hot subsurface of other planets. These studies are also expected to have economic benefits by: 1) better explaining the generation of economically important ore deposits; 2) providing new strategies for the remediation of toxic organic and metal contaminants; and 3) suggesting a new approach for increased recovery of hydrocarbons from petroleum reservoirs.

0085365微生物被认为对热（80-110摄氏度）的地球化学有重要影响，氧气耗尽的环境，如地球表面以下深处，海洋底部和陆地温泉周围的环境。 本研究的目的是评估厌氧超嗜热微生物的代谢多样性，以了解更多关于在热微生物生态系统中可能发生的生物地球化学过程。 据推测，存在多种多样的微生物，它们能够通过氧化有机化合物而在热环境中生存，所述有机化合物例如：乙酸盐和其他短链脂肪酸、长链脂肪酸、氨基酸、芳香族化合物和各种烃。 预测这些有机化合物的氧化的电子受体包括Fe（III）、硫酸盐、S（零）或硝酸盐。 有人提出，在没有这些电子受体的情况下，这些有机化合物可以被微生物转化为甲烷。 将采用新的策略，试图恢复自养，氢氧化，Fe（III）还原超嗜热菌，因为它是假设，一些生物体与这种形式的呼吸将在最深的分支微生物仍然存在于地球上。 为了评估的可能性，Fe（III）还原剂可能是活跃的热，酸性环境中，将尝试恢复嗜酸性hyperthermophiles，可以减少可溶性Fe（III）发现在低pH值的可能性，Fe（III）-还原hyperthermophiles产生同位素独特的Fe（II）矿物将通过检查这些矿物中的氧和铁同位素进行评估。 预计这些研究将进一步深入了解地球上炎热微生物生态系统的生物学和地质学，以及可能存在于其他行星炎热地下的微生物生态系统。 预计这些研究还将通过以下方式产生经济效益：1）更好地解释具有重要经济意义的矿床的产生; 2）为有毒有机和金属污染物的补救提供新的战略; 3）提出一种新的方法，以增加从石油储层中回收碳氢化合物。