Metabolic Engineering Studies of Extreme Thermoacidophily

极端嗜热(生长~60℃，pH S 3)是一种值得注意的生长生理 由克伦考古群和Eurya chaeota的某些成员展出，主要的古生物 门。这组微生物的有趣特征包括：利用高pH 通过细胞膜的梯度来驱动质子泵以保持近中性 胞质，耐正常毒性水平的碱金属和重金属，生长能力 自养固定二氧化碳，异养固定在多肽上，或混合营养，通过使用两者 模式，基于还原金属和硫物种异化氧化的生物能量学， 独特的膜和S层，以及分子氢的战略性刺激生长 将部分或全部这些生理特征整合到细胞新陈代谢中，即在热酸中的生命 成为可能。然而，除了生物化学之外，人们对这种情况是如何发生的知之甚少。 这些微生物中几种蛋白质的特性及其基本途径 分析。然而，如果了解了这些功能背后的机制，那么对 定义极端嗜热性的生物学策略将会产生。这种洞察力具有 重要的科学和技术重要性。例如，很明显， Crenarcheaota(并不是所有的都是极端嗜热的)组成了一个重要的 占全球生物量的一小部分，并与极端生态位以外的领域相关。这些生物体 在全球碳循环、氮循环、共生和 真核生物的相互作用。观察到的转录和翻译机制 古生菌与真核生物中的古生菌密切相关，因此提供了一种极好的 另一种视角。最后，细胞在极端条件下存活的线索可能导致 关于高等真核生物生存压力的有趣的医学策略。的目标 本课题的主要内容是：1)确定极端营养途径的组成 嗜热性金属球藻以及这些过程是如何相互关联的 融入整体细胞生物能量学；2)研究M。 车前草固有的重金属和贱金属抗性；3)整合从 目标1和2，包括转录因子、染色质修饰和毒素-抗毒素的研究 位点，以推导出一个概念模型的草莓转录调控系统。

Extreme thermoacidophily (growth ~ 60¿C, pH s 3) is a remarkable growth physiology exhibited by certain members of the Crenarchaeota and Euryarchaeota, the major archaeal phyla. Interesting features of microorganisms in this group include: exploitation of large pH gradients across the cell membrane to drive proton pumping for maintaining a near neutral cytosol, resistance to normally toxic levels of base and heavy metals, capacity to grow autotrophically by fixing CO2, heterotrophically on peptides, or mixotrophically by using both modes, bioenergetics based on dissimilatory oxidation of reduced metal and sulfur species, unique membranes and S-Iayers, and growth stimulation by molecular H2¿ By strategically integrating some or all of these physiological features into cellular metabolism, life in hot acid becomes possible. However, little is known about how this happens beyond biochemical characterization of a few proteins from these microorganisms and rudimentary pathway analysis. Yet, if the mechanisms behind these features were understood, insights into the biological strategies that define extreme thermoacidophily would result. Such insights have important scientific and technological importance. For example, it is clear that the Crenarcheaota (not all of which are extreme thermoacidophiles) comprise a significant fraction of the global biomass, and are relevant beyond extreme niches. These organisms play an expanding role in global carbon cycling, nitrogen cycling, symbiosis and eukaryotic interactions. The transcriptional and translational mechanisms observed in archaea are closely related to those found in eukaryotes and, thus, provide an excellent alternative perspective. Finally, clues to cellular survival under extreme conditions could lead to interesting medical strategies for surviving stress for higher eukaryotes. The objectives of this project are: 1) Determine the components of Iithotrophic pathways in the extreme thermoacidophile Metallosphaera sedula and how these processes relate to one another and integrate into overall cellular bioenergetics; 2) Investigate the metallomics underlying M. sedula's intrinsic heavy and base metal resistance; 3) Integrate the findings gained from aims 1 and 2 with studies on transcription factors, chromatin modification, and toxin-antitoxin loci to derive a conceptual model for the M. sedula transcription regulatory system.