Microbiology of the Chicxulub Impact Crater

深层地下被认为是一个支持巨大而多样的微生物生物圈的环境，但我们仍然对微生物在这种环境中如何生长，它们的空间多样性是什么以及这种多样性是如何受地下地球化学条件控制的知之甚少。以前的研究主要集中在深海沉积物上。在这些环境中的工作表明，地球化学界面对确定地下生物圈的多样性很重要。海洋环境中的地下生物圈与大陆环境中的地下生物圈相比，我们所知甚少。我们的实验室将于2016年4月至5月在IODP第364次探险期间，从埋在墨西哥湾下的6600万年前的希克苏鲁伯撞击结构的峰值环收集岩芯样本。这种白垩纪末期的撞击结构被认为是导致恐龙和当时75%的其他生命灭绝的原因。钻孔岩心将被回收，微生物污染控制到约1.5公里深度。因此，钻孔岩心提供了研究大陆地区地下微生物学的机会，以及微生物多样性与独特但明确的地下岩性序列之间的关系。在这个项目中，我们建议使用这些岩心来获得对地下微生物多样性的新见解。在这个项目中，我们将：1)通过岩心量化微生物的生物量，并将其与岩性相关联，以了解大陆深层地下微生物的生命如何受到岩性的影响；2)具体研究微生物丰度和多样性如何与撞击岩性相关联，以了解撞击如何破坏深层地下生物圈；3)培养和使用“组学”方法，如宏基因组学，通过核心了解生物的功能能力和代谢如何与环境和岩性相关联，从而更好地了解深层地下微生物的生物地球化学过程，特别是在撞击坑中；4)利用上述数据更广泛地了解生命是如何重新定居在陨石坑上的，以及陨石坑是如何为生命提供栖息地的，尽管对大型地表生活生物造成了灾难性的影响。

The deep subsurface is recognised to be an environment that supports a large and diverse microbial biosphere, and yet we still know very little about how microorganisms grow in this environment, what their spatial diversity is and how this diversity is controlled by subsurface geochemical conditions. Previous research has primarily focused on deep-ocean sediments. Work in these environments has shown that geochemical interfaces are important for determining the diversity of the subsurface biosphere. Little is known about how the subsurface biosphere in marine environments compares to that in continental subsurface environments.Our laboratory will acquire core samples collected from the peak ring of the 66 million-year old Chicxulub impact structure buried beneath the Gulf of Mexico in April-May 2016 during IODP Expedition 364. This end-Cretaceous impact structure is hypothesised to have been responsible for causing the extinction of the dinosaurs and ~75% of all other life at this time. The drill core will be retrieved with microbiological contamination control to ~1.5 km depth. Thus, the drill core offers the opportunity to investigate the subsurface microbiology of a continental site and also how the microbial diversity relates to a unique, but well-defined subsurface lithologic sequence. In this project we propose to use these cores to gain new insights into the diversity of microorganisms in the subsurface. In this project we will: 1) Quantify the biomass of microorganisms through the core and correlate it to the lithologies to understand how microbial life in the continental deep subsurface is influenced by lithology, 2) Specifically investigate how microbial abundance and diversity is correlated to impact lithologies to understand how impacts can disrupt the deep subsurface biosphere, 3) Culture and use '-omics' methods such as metagenomics to understand how the functional capabilities and metabolisms of organisms correlate to the environment and lithology through the core to gain a better understanding of microbial biogeochemical processes in the deep subsurface in general and specifically in an impact crater, 4) Use the above data to understand more generally how life recolonises impact craters and how craters might provide a habitat for life despite otherwise catastrophic effects on large surface dwelling life.