Collaborative research: BEE: Discovery and characterization of novel microbial lineages in an early Earth analog sulfur-based ecosystem.

地球上生命的进化与地球表面发生的地质变化密切相关。早期地球地质和大气的变化推动了适应当时新环境的新微生物的进化。因此，这些新进化的微生物的生长与新的最终产物，如氧气、二氧化碳和硫化物的产生有关，这反过来又极大地影响了地球上的物理条件，在生物学和地质学之间形成了一个永无止境的反馈循环。到目前为止，人们还不清楚早期地球上生活着什么类型的微生物。早期的单细胞生物很脆弱，没有骨头，没有保存下来。由于直接抽样是不可能的，因此有必要采用另一种办法，即查明当前地点的条件与过去世代普遍存在的条件相似。研究人员在俄克拉何马州西南部确定了一个独特的地点（佐德尔顿泉），那里春天不同地点的物理条件与地球历史上不同地质时期的普遍条件非常吻合。因此，Zodletone spring的空间采样可以代替不可接近的时间尺度。该项目将利用一系列尖端的实验室方法来描述这个独特地点的微生物群落。这些知识将有助于我们理解地球上的生命是如何进化的，以及它在太阳系内外的其他行星和天体上潜在进化的先决条件。这项研究将有助于两个州的多名高中生、本科生和研究生的劳动力培训，特别强调来自科学领域代表性不足的群体的学生。该项目的总体目标是鉴定和描述佐德尔顿春季普遍存在的新型细菌谱系：一个表面，光照，缺氧（富含硫化物）的栖息地，代表早期地球的模拟物。研究人员将结合基因组解析宏基因组学、代谢重建、群落转录组学、靶向分离、全球多样性和泛基因组学调查，对春季遇到的新的尚未培养的细菌谱系进行表征。这将通过：1)代谢重建来推断春季从不同地点恢复的未培养世系的代谢潜力和生理偏好；2)利用表达研究和基于反向基因组学的分离策略验证所提出的代谢能力和生态作用；3)利用数据挖掘方法和比较基因组学策略评估已鉴定谱系的全球分布格局和全基因组多样性，以追踪这些新谱系的生态成功/退缩/灭绝。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Evolution of life on Earth is closely linked to geological changes occurring at its surface. Changes in early Earth’s geology and atmosphere drove the evolution of new microorganisms adapted to the prevailing new conditions. Consequently, growth of these newly-evolved microorganisms was associated with the production of new end products such as oxygen, carbon dioxide, and sulfides, that in turn greatly impacted the physical conditions on Earth in a never-ending feedback loop between biology and geology. So far, it is not clearly understood what types of microorganisms inhabited early Earth. Early unicellular lifeforms are fragile, boneless, and have not been preserved. Since direct sampling is impossible, an alternative approach based on the identification of current locations with conditions paralleling those prevailing in past eons is warranted. The researchers have identified a unique site in southwestern Oklahoma (Zodletone spring), where physical conditions at various locations in the spring remarkably correspond to conditions prevalent at various geological eons throughout Earth’s history. Therefore, spatial sampling in Zodletone spring can substitute for inaccessible temporal time scales. The project will utilize a range of cutting-edge laboratory methodologies to characterize the microbial community in this unique site. This knowledge will contribute to our understanding of how life evolved on Earth, and the prerequisites for its potential evolution on other planets and celestial objects within the solar system and beyond. The research will contribute to workforce training of multiple high-school, undergraduate, and graduate students in two states with special emphasis on students from groups that are underrepresented in science. The overall goal of this project is to identify and characterize novel bacterial lineages prevalent in Zodletone spring: a surficial, light-exposed, and euxinic (anoxic, sulfide-rich) habitat representing an early Earth analog. The researchers will characterize novel yet-uncultured bacterial lineages encountered in the spring using a combination of genome-resolved metagenomics, metabolic reconstruction, community transcriptomics, targeted isolation, and global diversity and pangenomic surveys. This will be achieved by: 1) Metabolic reconstruction to deduce the metabolic potential and physiological preferences of uncultured lineages recovered from various locations in the spring; 2) Validating the proposed metabolic capabilities and ecological roles using expression studies and reverse-genomics based isolation strategies, and; 3) Assessing the global distribution patterns and pangenomic diversity of the identified lineages using data mining approaches and comparative genomics strategies to trace the ecological success/retreat/extinction of these novel lineages.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.